MQTT seems to work

.cproject

@@ -22,6 +22,11 @@
 									<listOptionValue builtIn="false" value="&quot;${workspace_loc:/RelayBox/arduino/core}&quot;"/>
 									<listOptionValue builtIn="false" value="&quot;${workspace_loc:/RelayBox/arduino/variant}&quot;"/>
 									<listOptionValue builtIn="false" value="&quot;${workspace_loc:/RelayBox/Streaming}&quot;"/>
+									<listOptionValue builtIn="false" value="&quot;${workspace_loc:/RelayBox/MQTT}&quot;"/>
+									<listOptionValue builtIn="false" value="&quot;${workspace_loc:/RelayBox/Ethernet}&quot;"/>
+									<listOptionValue builtIn="false" value="&quot;${workspace_loc:/RelayBox/SPI}&quot;"/>
+									<listOptionValue builtIn="false" value="&quot;${workspace_loc:/RelayBox/Metro}&quot;"/>
+									<listOptionValue builtIn="false" value="&quot;${workspace_loc:/RelayBox/PString}&quot;"/>
 								</option>
 								<inputType id="it.baeyens.arduino.compiler.cpp.sketch.input.1672155813" name="CPP source files" superClass="it.baeyens.arduino.compiler.cpp.sketch.input"/>
 							</tool>
@@ -30,6 +35,11 @@
 									<listOptionValue builtIn="false" value="&quot;${workspace_loc:/RelayBox/arduino/core}&quot;"/>
 									<listOptionValue builtIn="false" value="&quot;${workspace_loc:/RelayBox/arduino/variant}&quot;"/>
 									<listOptionValue builtIn="false" value="&quot;${workspace_loc:/RelayBox/Streaming}&quot;"/>
+									<listOptionValue builtIn="false" value="&quot;${workspace_loc:/RelayBox/MQTT}&quot;"/>
+									<listOptionValue builtIn="false" value="&quot;${workspace_loc:/RelayBox/Ethernet}&quot;"/>
+									<listOptionValue builtIn="false" value="&quot;${workspace_loc:/RelayBox/SPI}&quot;"/>
+									<listOptionValue builtIn="false" value="&quot;${workspace_loc:/RelayBox/Metro}&quot;"/>
+									<listOptionValue builtIn="false" value="&quot;${workspace_loc:/RelayBox/PString}&quot;"/>
 								</option>
 								<inputType id="it.baeyens.arduino.compiler.c.sketch.input.631198041" name="C Source Files" superClass="it.baeyens.arduino.compiler.c.sketch.input"/>
 							</tool>
@@ -42,7 +52,12 @@
 						</toolChain>
 					</folderInfo>
 					<sourceEntries>
-						<entry excluding="Streaming|Libraries/*/?xamples|Libraries/*/?xtras" flags="VALUE_WORKSPACE_PATH" kind="sourcePath" name=""/>
+						<entry excluding="PString|Metro|SPI|Ethernet|MQTT|Streaming|Libraries/*/?xamples|Libraries/*/?xtras" flags="VALUE_WORKSPACE_PATH" kind="sourcePath" name=""/>
+						<entry flags="VALUE_WORKSPACE_PATH|RESOLVED" kind="sourcePath" name="Ethernet"/>
+						<entry flags="VALUE_WORKSPACE_PATH|RESOLVED" kind="sourcePath" name="MQTT"/>
+						<entry flags="VALUE_WORKSPACE_PATH|RESOLVED" kind="sourcePath" name="Metro"/>
+						<entry flags="VALUE_WORKSPACE_PATH|RESOLVED" kind="sourcePath" name="PString"/>
+						<entry flags="VALUE_WORKSPACE_PATH|RESOLVED" kind="sourcePath" name="SPI"/>
 						<entry flags="VALUE_WORKSPACE_PATH|RESOLVED" kind="sourcePath" name="Streaming"/>
 					</sourceEntries>
 				</configuration>

.hgignore

@@ -0,0 +1,3 @@
+
+syntax: regexp
+^Release$

Ethernet/Dhcp.cpp

@@ -0,0 +1,481 @@
+// DHCP Library v0.3 - April 25, 2009
+// Author: Jordan Terrell - blog.jordanterrell.com
+
+#include "utility/w5100.h"
+
+#include <string.h>
+#include <stdlib.h>
+#include "Dhcp.h"
+#include "Arduino.h"
+#include "utility/util.h"
+
+int DhcpClass::beginWithDHCP(uint8_t *mac, unsigned long timeout, unsigned long responseTimeout)
+{
+    _dhcpLeaseTime=0;
+    _dhcpT1=0;
+    _dhcpT2=0;
+    _lastCheck=0;
+    _timeout = timeout;
+    _responseTimeout = responseTimeout;
+
+    // zero out _dhcpMacAddr
+    memset(_dhcpMacAddr, 0, 6); 
+    reset_DHCP_lease();
+
+    memcpy((void*)_dhcpMacAddr, (void*)mac, 6);
+    _dhcp_state = STATE_DHCP_START;
+    return request_DHCP_lease();
+}
+
+void DhcpClass::reset_DHCP_lease(){
+    // zero out _dhcpSubnetMask, _dhcpGatewayIp, _dhcpLocalIp, _dhcpDhcpServerIp, _dhcpDnsServerIp
+    memset(_dhcpLocalIp, 0, 20);
+}
+
+//return:0 on error, 1 if request is sent and response is received
+int DhcpClass::request_DHCP_lease(){
+    
+    uint8_t messageType = 0;
+  
+    
+  
+    // Pick an initial transaction ID
+    _dhcpTransactionId = random(1UL, 2000UL);
+    _dhcpInitialTransactionId = _dhcpTransactionId;
+
+    _dhcpUdpSocket.stop();
+    if (_dhcpUdpSocket.begin(DHCP_CLIENT_PORT) == 0)
+    {
+      // Couldn't get a socket
+      return 0;
+    }
+    
+    presend_DHCP();
+    
+    int result = 0;
+    
+    unsigned long startTime = millis();
+    
+    while(_dhcp_state != STATE_DHCP_LEASED)
+    {
+        if(_dhcp_state == STATE_DHCP_START)
+        {
+            _dhcpTransactionId++;
+            
+            send_DHCP_MESSAGE(DHCP_DISCOVER, ((millis() - startTime) / 1000));
+            _dhcp_state = STATE_DHCP_DISCOVER;
+        }
+        else if(_dhcp_state == STATE_DHCP_REREQUEST){
+            _dhcpTransactionId++;
+            send_DHCP_MESSAGE(DHCP_REQUEST, ((millis() - startTime)/1000));
+            _dhcp_state = STATE_DHCP_REQUEST;
+        }
+        else if(_dhcp_state == STATE_DHCP_DISCOVER)
+        {
+            uint32_t respId;
+            messageType = parseDHCPResponse(_responseTimeout, respId);
+            if(messageType == DHCP_OFFER)
+            {
+                // We'll use the transaction ID that the offer came with,
+                // rather than the one we were up to
+                _dhcpTransactionId = respId;
+                send_DHCP_MESSAGE(DHCP_REQUEST, ((millis() - startTime) / 1000));
+                _dhcp_state = STATE_DHCP_REQUEST;
+            }
+        }
+        else if(_dhcp_state == STATE_DHCP_REQUEST)
+        {
+            uint32_t respId;
+            messageType = parseDHCPResponse(_responseTimeout, respId);
+            if(messageType == DHCP_ACK)
+            {
+                _dhcp_state = STATE_DHCP_LEASED;
+                result = 1;
+                //use default lease time if we didn't get it
+                if(_dhcpLeaseTime == 0){
+                    _dhcpLeaseTime = DEFAULT_LEASE;
+                }
+                //calculate T1 & T2 if we didn't get it
+                if(_dhcpT1 == 0){
+                    //T1 should be 50% of _dhcpLeaseTime
+                    _dhcpT1 = _dhcpLeaseTime >> 1;
+                }
+                if(_dhcpT2 == 0){
+                    //T2 should be 87.5% (7/8ths) of _dhcpLeaseTime
+                    _dhcpT2 = _dhcpT1 << 1;
+                }
+                _renewInSec = _dhcpT1;
+                _rebindInSec = _dhcpT2;
+            }
+            else if(messageType == DHCP_NAK)
+                _dhcp_state = STATE_DHCP_START;
+        }
+        
+        if(messageType == 255)
+        {
+            messageType = 0;
+            _dhcp_state = STATE_DHCP_START;
+        }
+        
+        if(result != 1 && ((millis() - startTime) > _timeout))
+            break;
+    }
+    
+    // We're done with the socket now
+    _dhcpUdpSocket.stop();
+    _dhcpTransactionId++;
+
+    return result;
+}
+
+void DhcpClass::presend_DHCP()
+{
+}
+
+void DhcpClass::send_DHCP_MESSAGE(uint8_t messageType, uint16_t secondsElapsed)
+{
+    uint8_t buffer[32];
+    memset(buffer, 0, 32);
+    IPAddress dest_addr( 255, 255, 255, 255 ); // Broadcast address
+
+    if (-1 == _dhcpUdpSocket.beginPacket(dest_addr, DHCP_SERVER_PORT))
+    {
+        // FIXME Need to return errors
+        return;
+    }
+
+    buffer[0] = DHCP_BOOTREQUEST;   // op
+    buffer[1] = DHCP_HTYPE10MB;     // htype
+    buffer[2] = DHCP_HLENETHERNET;  // hlen
+    buffer[3] = DHCP_HOPS;          // hops
+
+    // xid
+    unsigned long xid = htonl(_dhcpTransactionId);
+    memcpy(buffer + 4, &(xid), 4);
+
+    // 8, 9 - seconds elapsed
+    buffer[8] = ((secondsElapsed & 0xff00) >> 8);
+    buffer[9] = (secondsElapsed & 0x00ff);
+
+    // flags
+    unsigned short flags = htons(DHCP_FLAGSBROADCAST);
+    memcpy(buffer + 10, &(flags), 2);
+
+    // ciaddr: already zeroed
+    // yiaddr: already zeroed
+    // siaddr: already zeroed
+    // giaddr: already zeroed
+
+    //put data in W5100 transmit buffer
+    _dhcpUdpSocket.write(buffer, 28);
+
+    memset(buffer, 0, 32); // clear local buffer
+
+    memcpy(buffer, _dhcpMacAddr, 6); // chaddr
+
+    //put data in W5100 transmit buffer
+    _dhcpUdpSocket.write(buffer, 16);
+
+    memset(buffer, 0, 32); // clear local buffer
+
+    // leave zeroed out for sname && file
+    // put in W5100 transmit buffer x 6 (192 bytes)
+  
+    for(int i = 0; i < 6; i++) {
+        _dhcpUdpSocket.write(buffer, 32);
+    }
+  
+    // OPT - Magic Cookie
+    buffer[0] = (uint8_t)((MAGIC_COOKIE >> 24)& 0xFF);
+    buffer[1] = (uint8_t)((MAGIC_COOKIE >> 16)& 0xFF);
+    buffer[2] = (uint8_t)((MAGIC_COOKIE >> 8)& 0xFF);
+    buffer[3] = (uint8_t)(MAGIC_COOKIE& 0xFF);
+
+    // OPT - message type
+    buffer[4] = dhcpMessageType;
+    buffer[5] = 0x01;
+    buffer[6] = messageType; //DHCP_REQUEST;
+
+    // OPT - client identifier
+    buffer[7] = dhcpClientIdentifier;
+    buffer[8] = 0x07;
+    buffer[9] = 0x01;
+    memcpy(buffer + 10, _dhcpMacAddr, 6);
+
+    // OPT - host name
+    buffer[16] = hostName;
+    buffer[17] = strlen(HOST_NAME) + 6; // length of hostname + last 3 bytes of mac address
+    strcpy((char*)&(buffer[18]), HOST_NAME);
+
+    printByte((char*)&(buffer[24]), _dhcpMacAddr[3]);
+    printByte((char*)&(buffer[26]), _dhcpMacAddr[4]);
+    printByte((char*)&(buffer[28]), _dhcpMacAddr[5]);
+
+    //put data in W5100 transmit buffer
+    _dhcpUdpSocket.write(buffer, 30);
+
+    if(messageType == DHCP_REQUEST)
+    {
+        buffer[0] = dhcpRequestedIPaddr;
+        buffer[1] = 0x04;
+        buffer[2] = _dhcpLocalIp[0];
+        buffer[3] = _dhcpLocalIp[1];
+        buffer[4] = _dhcpLocalIp[2];
+        buffer[5] = _dhcpLocalIp[3];
+
+        buffer[6] = dhcpServerIdentifier;
+        buffer[7] = 0x04;
+        buffer[8] = _dhcpDhcpServerIp[0];
+        buffer[9] = _dhcpDhcpServerIp[1];
+        buffer[10] = _dhcpDhcpServerIp[2];
+        buffer[11] = _dhcpDhcpServerIp[3];
+
+        //put data in W5100 transmit buffer
+        _dhcpUdpSocket.write(buffer, 12);
+    }
+    
+    buffer[0] = dhcpParamRequest;
+    buffer[1] = 0x06;
+    buffer[2] = subnetMask;
+    buffer[3] = routersOnSubnet;
+    buffer[4] = dns;
+    buffer[5] = domainName;
+    buffer[6] = dhcpT1value;
+    buffer[7] = dhcpT2value;
+    buffer[8] = endOption;
+    
+    //put data in W5100 transmit buffer
+    _dhcpUdpSocket.write(buffer, 9);
+
+    _dhcpUdpSocket.endPacket();
+}
+
+uint8_t DhcpClass::parseDHCPResponse(unsigned long responseTimeout, uint32_t& transactionId)
+{
+    uint8_t type = 0;
+    uint8_t opt_len = 0;
+     
+    unsigned long startTime = millis();
+
+    while(_dhcpUdpSocket.parsePacket() <= 0)
+    {
+        if((millis() - startTime) > responseTimeout)
+        {
+            return 255;
+        }
+        delay(50);
+    }
+    // start reading in the packet
+    RIP_MSG_FIXED fixedMsg;
+    _dhcpUdpSocket.read((uint8_t*)&fixedMsg, sizeof(RIP_MSG_FIXED));
+  
+    if(fixedMsg.op == DHCP_BOOTREPLY && _dhcpUdpSocket.remotePort() == DHCP_SERVER_PORT)
+    {
+        transactionId = ntohl(fixedMsg.xid);
+        if(memcmp(fixedMsg.chaddr, _dhcpMacAddr, 6) != 0 || (transactionId < _dhcpInitialTransactionId) || (transactionId > _dhcpTransactionId))
+        {
+            // Need to read the rest of the packet here regardless
+            _dhcpUdpSocket.flush();
+            return 0;
+        }
+
+        memcpy(_dhcpLocalIp, fixedMsg.yiaddr, 4);
+
+        // Skip to the option part
+        // Doing this a byte at a time so we don't have to put a big buffer
+        // on the stack (as we don't have lots of memory lying around)
+        for (int i =0; i < (240 - (int)sizeof(RIP_MSG_FIXED)); i++)
+        {
+            _dhcpUdpSocket.read(); // we don't care about the returned byte
+        }
+
+        while (_dhcpUdpSocket.available() > 0) 
+        {
+            switch (_dhcpUdpSocket.read()) 
+            {
+                case endOption :
+                    break;
+                    
+                case padOption :
+                    break;
+                
+                case dhcpMessageType :
+                    opt_len = _dhcpUdpSocket.read();
+                    type = _dhcpUdpSocket.read();
+                    break;
+                
+                case subnetMask :
+                    opt_len = _dhcpUdpSocket.read();
+                    _dhcpUdpSocket.read(_dhcpSubnetMask, 4);
+                    break;
+                
+                case routersOnSubnet :
+                    opt_len = _dhcpUdpSocket.read();
+                    _dhcpUdpSocket.read(_dhcpGatewayIp, 4);
+                    for (int i = 0; i < opt_len-4; i++)
+                    {
+                        _dhcpUdpSocket.read();
+                    }
+                    break;
+                
+                case dns :
+                    opt_len = _dhcpUdpSocket.read();
+                    _dhcpUdpSocket.read(_dhcpDnsServerIp, 4);
+                    for (int i = 0; i < opt_len-4; i++)
+                    {
+                        _dhcpUdpSocket.read();
+                    }
+                    break;
+                
+                case dhcpServerIdentifier :
+                    opt_len = _dhcpUdpSocket.read();
+                    if ((_dhcpDhcpServerIp[0] == 0 && _dhcpDhcpServerIp[1] == 0 &&
+                         _dhcpDhcpServerIp[2] == 0 && _dhcpDhcpServerIp[3] == 0) ||
+                        IPAddress(_dhcpDhcpServerIp) == _dhcpUdpSocket.remoteIP())
+                    {
+                        _dhcpUdpSocket.read(_dhcpDhcpServerIp, sizeof(_dhcpDhcpServerIp));
+                    }
+                    else
+                    {
+                        // Skip over the rest of this option
+                        while (opt_len--)
+                        {
+                            _dhcpUdpSocket.read();
+                        }
+                    }
+                    break;
+
+                case dhcpT1value : 
+                    opt_len = _dhcpUdpSocket.read();
+                    _dhcpUdpSocket.read((uint8_t*)&_dhcpT1, sizeof(_dhcpT1));
+                    _dhcpT1 = ntohl(_dhcpT1);
+                    break;
+
+                case dhcpT2value : 
+                    opt_len = _dhcpUdpSocket.read();
+                    _dhcpUdpSocket.read((uint8_t*)&_dhcpT2, sizeof(_dhcpT2));
+                    _dhcpT2 = ntohl(_dhcpT2);
+                    break;
+
+                case dhcpIPaddrLeaseTime :
+                    opt_len = _dhcpUdpSocket.read();
+                    _dhcpUdpSocket.read((uint8_t*)&_dhcpLeaseTime, sizeof(_dhcpLeaseTime));
+                    _dhcpLeaseTime = ntohl(_dhcpLeaseTime);
+                    _renewInSec = _dhcpLeaseTime;
+                    break;
+
+                default :
+                    opt_len = _dhcpUdpSocket.read();
+                    // Skip over the rest of this option
+                    while (opt_len--)
+                    {
+                        _dhcpUdpSocket.read();
+                    }
+                    break;
+            }
+        }
+    }
+
+    // Need to skip to end of the packet regardless here
+    _dhcpUdpSocket.flush();
+
+    return type;
+}
+
+
+/*
+    returns:
+    0/DHCP_CHECK_NONE: nothing happened
+    1/DHCP_CHECK_RENEW_FAIL: renew failed
+    2/DHCP_CHECK_RENEW_OK: renew success
+    3/DHCP_CHECK_REBIND_FAIL: rebind fail
+    4/DHCP_CHECK_REBIND_OK: rebind success
+*/
+int DhcpClass::checkLease(){
+    //this uses a signed / unsigned trick to deal with millis overflow
+    unsigned long now = millis();
+    signed long snow = (long)now;
+    int rc=DHCP_CHECK_NONE;
+    if (_lastCheck != 0){
+        signed long factor;
+        //calc how many ms past the timeout we are
+        factor = snow - (long)_secTimeout;
+        //if on or passed the timeout, reduce the counters
+        if ( factor >= 0 ){
+            //next timeout should be now plus 1000 ms minus parts of second in factor
+            _secTimeout = snow + 1000 - factor % 1000;
+            //how many seconds late are we, minimum 1
+            factor = factor / 1000 +1;
+            
+            //reduce the counters by that mouch
+            //if we can assume that the cycle time (factor) is fairly constant
+            //and if the remainder is less than cycle time * 2 
+            //do it early instead of late
+            if(_renewInSec < factor*2 )
+                _renewInSec = 0;
+            else
+                _renewInSec -= factor;
+            
+            if(_rebindInSec < factor*2 )
+                _rebindInSec = 0;
+            else
+                _rebindInSec -= factor;
+        }
+
+        //if we have a lease but should renew, do it
+        if (_dhcp_state == STATE_DHCP_LEASED && _renewInSec <=0){
+            _dhcp_state = STATE_DHCP_REREQUEST;
+            rc = 1 + request_DHCP_lease();
+        }
+
+        //if we have a lease or is renewing but should bind, do it
+        if( (_dhcp_state == STATE_DHCP_LEASED || _dhcp_state == STATE_DHCP_START) && _rebindInSec <=0){
+            //this should basically restart completely
+            _dhcp_state = STATE_DHCP_START;
+            reset_DHCP_lease();
+            rc = 3 + request_DHCP_lease();
+        }
+    }
+    else{
+        _secTimeout = snow + 1000;
+    }
+
+    _lastCheck = now;
+    return rc;
+}
+
+IPAddress DhcpClass::getLocalIp()
+{
+    return IPAddress(_dhcpLocalIp);
+}
+
+IPAddress DhcpClass::getSubnetMask()
+{
+    return IPAddress(_dhcpSubnetMask);
+}
+
+IPAddress DhcpClass::getGatewayIp()
+{
+    return IPAddress(_dhcpGatewayIp);
+}
+
+IPAddress DhcpClass::getDhcpServerIp()
+{
+    return IPAddress(_dhcpDhcpServerIp);
+}
+
+IPAddress DhcpClass::getDnsServerIp()
+{
+    return IPAddress(_dhcpDnsServerIp);
+}
+
+void DhcpClass::printByte(char * buf, uint8_t n ) {
+  char *str = &buf[1];
+  buf[0]='0';
+  do {
+    unsigned long m = n;
+    n /= 16;
+    char c = m - 16 * n;
+    *str-- = c < 10 ? c + '0' : c + 'A' - 10;
+  } while(n);
+}

Ethernet/Dhcp.h

@@ -0,0 +1,178 @@
+// DHCP Library v0.3 - April 25, 2009
+// Author: Jordan Terrell - blog.jordanterrell.com
+
+#ifndef Dhcp_h
+#define Dhcp_h
+
+#include "EthernetUdp.h"
+
+/* DHCP state machine. */
+#define STATE_DHCP_START 0
+#define	STATE_DHCP_DISCOVER	1
+#define	STATE_DHCP_REQUEST	2
+#define	STATE_DHCP_LEASED	3
+#define	STATE_DHCP_REREQUEST	4
+#define	STATE_DHCP_RELEASE	5
+
+#define DHCP_FLAGSBROADCAST	0x8000
+
+/* UDP port numbers for DHCP */
+#define	DHCP_SERVER_PORT	67	/* from server to client */
+#define DHCP_CLIENT_PORT	68	/* from client to server */
+
+/* DHCP message OP code */
+#define DHCP_BOOTREQUEST	1
+#define DHCP_BOOTREPLY		2
+
+/* DHCP message type */
+#define	DHCP_DISCOVER		1
+#define DHCP_OFFER		  2
+#define	DHCP_REQUEST		3
+#define	DHCP_DECLINE		4
+#define	DHCP_ACK		    5
+#define DHCP_NAK		    6
+#define	DHCP_RELEASE		7
+#define DHCP_INFORM		  8
+
+#define DHCP_HTYPE10MB		1
+#define DHCP_HTYPE100MB		2
+
+#define DHCP_HLENETHERNET	6
+#define DHCP_HOPS		0
+#define DHCP_SECS		0
+
+#define MAGIC_COOKIE		0x63825363
+#define MAX_DHCP_OPT	16
+
+#define HOST_NAME "WIZnet"
+#define DEFAULT_LEASE	(900) //default lease time in seconds
+
+#define DHCP_CHECK_NONE         (0)
+#define DHCP_CHECK_RENEW_FAIL   (1)
+#define DHCP_CHECK_RENEW_OK     (2)
+#define DHCP_CHECK_REBIND_FAIL  (3)
+#define DHCP_CHECK_REBIND_OK    (4)
+
+enum
+{
+	padOption		=	0,
+	subnetMask		=	1,
+	timerOffset		=	2,
+	routersOnSubnet		=	3,
+	/* timeServer		=	4,
+	nameServer		=	5,*/
+	dns			=	6,
+	/*logServer		=	7,
+	cookieServer		=	8,
+	lprServer		=	9,
+	impressServer		=	10,
+	resourceLocationServer	=	11,*/
+	hostName		=	12,
+	/*bootFileSize		=	13,
+	meritDumpFile		=	14,*/
+	domainName		=	15,
+	/*swapServer		=	16,
+	rootPath		=	17,
+	extentionsPath		=	18,
+	IPforwarding		=	19,
+	nonLocalSourceRouting	=	20,
+	policyFilter		=	21,
+	maxDgramReasmSize	=	22,
+	defaultIPTTL		=	23,
+	pathMTUagingTimeout	=	24,
+	pathMTUplateauTable	=	25,
+	ifMTU			=	26,
+	allSubnetsLocal		=	27,
+	broadcastAddr		=	28,
+	performMaskDiscovery	=	29,
+	maskSupplier		=	30,
+	performRouterDiscovery	=	31,
+	routerSolicitationAddr	=	32,
+	staticRoute		=	33,
+	trailerEncapsulation	=	34,
+	arpCacheTimeout		=	35,
+	ethernetEncapsulation	=	36,
+	tcpDefaultTTL		=	37,
+	tcpKeepaliveInterval	=	38,
+	tcpKeepaliveGarbage	=	39,
+	nisDomainName		=	40,
+	nisServers		=	41,
+	ntpServers		=	42,
+	vendorSpecificInfo	=	43,
+	netBIOSnameServer	=	44,
+	netBIOSdgramDistServer	=	45,
+	netBIOSnodeType		=	46,
+	netBIOSscope		=	47,
+	xFontServer		=	48,
+	xDisplayManager		=	49,*/
+	dhcpRequestedIPaddr	=	50,
+	dhcpIPaddrLeaseTime	=	51,
+	/*dhcpOptionOverload	=	52,*/
+	dhcpMessageType		=	53,
+	dhcpServerIdentifier	=	54,
+	dhcpParamRequest	=	55,
+	/*dhcpMsg			=	56,
+	dhcpMaxMsgSize		=	57,*/
+	dhcpT1value		=	58,
+	dhcpT2value		=	59,
+	/*dhcpClassIdentifier	=	60,*/
+	dhcpClientIdentifier	=	61,
+	endOption		=	255
+};
+
+typedef struct __attribute__((packed)) _RIP_MSG_FIXED
+{
+	uint8_t  op; 
+	uint8_t  htype; 
+	uint8_t  hlen;
+	uint8_t  hops;
+	uint32_t xid;
+	uint16_t secs;
+	uint16_t flags;
+	uint8_t  ciaddr[4];
+	uint8_t  yiaddr[4];
+	uint8_t  siaddr[4];
+	uint8_t  giaddr[4];
+	uint8_t  chaddr[6];
+}RIP_MSG_FIXED;
+
+class DhcpClass {
+private:
+  uint32_t _dhcpInitialTransactionId;
+  uint32_t _dhcpTransactionId;
+  uint8_t  _dhcpMacAddr[6];
+  uint8_t  _dhcpLocalIp[4];
+  uint8_t  _dhcpSubnetMask[4];
+  uint8_t  _dhcpGatewayIp[4];
+  uint8_t  _dhcpDhcpServerIp[4];
+  uint8_t  _dhcpDnsServerIp[4];
+  uint32_t _dhcpLeaseTime;
+  uint32_t _dhcpT1, _dhcpT2;
+  signed long _renewInSec;
+  signed long _rebindInSec;
+  signed long _lastCheck;
+  unsigned long _timeout;
+  unsigned long _responseTimeout;
+  unsigned long _secTimeout;
+  uint8_t _dhcp_state;
+  EthernetUDP _dhcpUdpSocket;
+  
+  int request_DHCP_lease();
+  void reset_DHCP_lease();
+  void presend_DHCP();
+  void send_DHCP_MESSAGE(uint8_t, uint16_t);
+  void printByte(char *, uint8_t);
+  
+  uint8_t parseDHCPResponse(unsigned long responseTimeout, uint32_t& transactionId);
+public:
+  IPAddress getLocalIp();
+  IPAddress getSubnetMask();
+  IPAddress getGatewayIp();
+  IPAddress getDhcpServerIp();
+  IPAddress getDnsServerIp();
+  
+  int beginWithDHCP(uint8_t *, unsigned long timeout = 60000, unsigned long responseTimeout = 4000);
+  int checkLease();
+};
+
+#endif

Ethernet/Dns.cpp

@@ -0,0 +1,423 @@
+// Arduino DNS client for WizNet5100-based Ethernet shield
+// (c) Copyright 2009-2010 MCQN Ltd.
+// Released under Apache License, version 2.0
+
+#include "utility/w5100.h"
+#include "EthernetUdp.h"
+#include "utility/util.h"
+
+#include "Dns.h"
+#include <string.h>
+//#include <stdlib.h>
+#include "Arduino.h"
+
+
+#define SOCKET_NONE	255
+// Various flags and header field values for a DNS message
+#define UDP_HEADER_SIZE	8
+#define DNS_HEADER_SIZE	12
+#define TTL_SIZE        4
+#define QUERY_FLAG               (0)
+#define RESPONSE_FLAG            (1<<15)
+#define QUERY_RESPONSE_MASK      (1<<15)
+#define OPCODE_STANDARD_QUERY    (0)
+#define OPCODE_INVERSE_QUERY     (1<<11)
+#define OPCODE_STATUS_REQUEST    (2<<11)
+#define OPCODE_MASK              (15<<11)
+#define AUTHORITATIVE_FLAG       (1<<10)
+#define TRUNCATION_FLAG          (1<<9)
+#define RECURSION_DESIRED_FLAG   (1<<8)
+#define RECURSION_AVAILABLE_FLAG (1<<7)
+#define RESP_NO_ERROR            (0)
+#define RESP_FORMAT_ERROR        (1)
+#define RESP_SERVER_FAILURE      (2)
+#define RESP_NAME_ERROR          (3)
+#define RESP_NOT_IMPLEMENTED     (4)
+#define RESP_REFUSED             (5)
+#define RESP_MASK                (15)
+#define TYPE_A                   (0x0001)
+#define CLASS_IN                 (0x0001)
+#define LABEL_COMPRESSION_MASK   (0xC0)
+// Port number that DNS servers listen on
+#define DNS_PORT        53
+
+// Possible return codes from ProcessResponse
+#define SUCCESS          1
+#define TIMED_OUT        -1
+#define INVALID_SERVER   -2
+#define TRUNCATED        -3
+#define INVALID_RESPONSE -4
+
+void DNSClient::begin(const IPAddress& aDNSServer)
+{
+    iDNSServer = aDNSServer;
+    iRequestId = 0;
+}
+
+
+int DNSClient::inet_aton(const char* aIPAddrString, IPAddress& aResult)
+{
+    // See if we've been given a valid IP address
+    const char* p =aIPAddrString;
+    while (*p &&
+           ( (*p == '.') || (*p >= '0') || (*p <= '9') ))
+    {
+        p++;
+    }
+
+    if (*p == '\0')
+    {
+        // It's looking promising, we haven't found any invalid characters
+        p = aIPAddrString;
+        int segment =0;
+        int segmentValue =0;
+        while (*p && (segment < 4))
+        {
+            if (*p == '.')
+            {
+                // We've reached the end of a segment
+                if (segmentValue > 255)
+                {
+                    // You can't have IP address segments that don't fit in a byte
+                    return 0;
+                }
+                else
+                {
+                    aResult[segment] = (byte)segmentValue;
+                    segment++;
+                    segmentValue = 0;
+                }
+            }
+            else
+            {
+                // Next digit
+                segmentValue = (segmentValue*10)+(*p - '0');
+            }
+            p++;
+        }
+        // We've reached the end of address, but there'll still be the last
+        // segment to deal with
+        if ((segmentValue > 255) || (segment > 3))
+        {
+            // You can't have IP address segments that don't fit in a byte,
+            // or more than four segments
+            return 0;
+        }
+        else
+        {
+            aResult[segment] = (byte)segmentValue;
+            return 1;
+        }
+    }
+    else
+    {
+        return 0;
+    }
+}
+
+int DNSClient::getHostByName(const char* aHostname, IPAddress& aResult)
+{
+    int ret =0;
+
+    // See if it's a numeric IP address
+    if (inet_aton(aHostname, aResult))
+    {
+        // It is, our work here is done
+        return 1;
+    }
+
+    // Check we've got a valid DNS server to use
+    if (iDNSServer == INADDR_NONE)
+    {
+        return INVALID_SERVER;
+    }
+	
+    // Find a socket to use
+    if (iUdp.begin(1024+(millis() & 0xF)) == 1)
+    {
+        // Try up to three times
+        int retries = 0;
+//        while ((retries < 3) && (ret <= 0))
+        {
+            // Send DNS request
+            ret = iUdp.beginPacket(iDNSServer, DNS_PORT);
+            if (ret != 0)
+            {
+                // Now output the request data
+                ret = BuildRequest(aHostname);
+                if (ret != 0)
+                {
+                    // And finally send the request
+                    ret = iUdp.endPacket();
+                    if (ret != 0)
+                    {
+                        // Now wait for a response
+                        int wait_retries = 0;
+                        ret = TIMED_OUT;
+                        while ((wait_retries < 3) && (ret == TIMED_OUT))
+                        {
+                            ret = ProcessResponse(5000, aResult);
+                            wait_retries++;
+                        }
+                    }
+                }
+            }
+            retries++;
+        }
+
+        // We're done with the socket now
+        iUdp.stop();
+    }
+
+    return ret;
+}
+
+uint16_t DNSClient::BuildRequest(const char* aName)
+{
+    // Build header
+    //                                    1  1  1  1  1  1
+    //      0  1  2  3  4  5  6  7  8  9  0  1  2  3  4  5
+    //    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+    //    |                      ID                       |
+    //    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+    //    |QR|   Opcode  |AA|TC|RD|RA|   Z    |   RCODE   |
+    //    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+    //    |                    QDCOUNT                    |
+    //    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+    //    |                    ANCOUNT                    |
+    //    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+    //    |                    NSCOUNT                    |
+    //    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+    //    |                    ARCOUNT                    |
+    //    +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+    // As we only support one request at a time at present, we can simplify
+    // some of this header
+    iRequestId = millis(); // generate a random ID
+    uint16_t twoByteBuffer;
+
+    // FIXME We should also check that there's enough space available to write to, rather
+    // FIXME than assume there's enough space (as the code does at present)
+    iUdp.write((uint8_t*)&iRequestId, sizeof(iRequestId));
+
+    twoByteBuffer = htons(QUERY_FLAG | OPCODE_STANDARD_QUERY | RECURSION_DESIRED_FLAG);
+    iUdp.write((uint8_t*)&twoByteBuffer, sizeof(twoByteBuffer));
+
+    twoByteBuffer = htons(1);  // One question record
+    iUdp.write((uint8_t*)&twoByteBuffer, sizeof(twoByteBuffer));
+
+    twoByteBuffer = 0;  // Zero answer records
+    iUdp.write((uint8_t*)&twoByteBuffer, sizeof(twoByteBuffer));
+
+    iUdp.write((uint8_t*)&twoByteBuffer, sizeof(twoByteBuffer));
+    // and zero additional records
+    iUdp.write((uint8_t*)&twoByteBuffer, sizeof(twoByteBuffer));
+
+    // Build question
+    const char* start =aName;
+    const char* end =start;
+    uint8_t len;
+    // Run through the name being requested
+    while (*end)
+    {
+        // Find out how long this section of the name is
+        end = start;
+        while (*end && (*end != '.') )
+        {
+            end++;
+        }
+
+        if (end-start > 0)
+        {
+            // Write out the size of this section
+            len = end-start;
+            iUdp.write(&len, sizeof(len));
+            // And then write out the section
+            iUdp.write((uint8_t*)start, end-start);
+        }
+        start = end+1;
+    }
+
+    // We've got to the end of the question name, so
+    // terminate it with a zero-length section
+    len = 0;
+    iUdp.write(&len, sizeof(len));
+    // Finally the type and class of question
+    twoByteBuffer = htons(TYPE_A);
+    iUdp.write((uint8_t*)&twoByteBuffer, sizeof(twoByteBuffer));
+
+    twoByteBuffer = htons(CLASS_IN);  // Internet class of question
+    iUdp.write((uint8_t*)&twoByteBuffer, sizeof(twoByteBuffer));
+    // Success!  Everything buffered okay
+    return 1;
+}
+
+
+uint16_t DNSClient::ProcessResponse(uint16_t aTimeout, IPAddress& aAddress)
+{
+    uint32_t startTime = millis();
+
+    // Wait for a response packet
+    while(iUdp.parsePacket() <= 0)
+    {
+        if((millis() - startTime) > aTimeout)
+            return TIMED_OUT;
+        delay(50);
+    }
+
+    // We've had a reply!
+    // Read the UDP header
+    uint8_t header[DNS_HEADER_SIZE]; // Enough space to reuse for the DNS header
+    // Check that it's a response from the right server and the right port
+    if ( (iDNSServer != iUdp.remoteIP()) || 
+        (iUdp.remotePort() != DNS_PORT) )
+    {
+        // It's not from who we expected
+        return INVALID_SERVER;
+    }
+
+    // Read through the rest of the response
+    if (iUdp.available() < DNS_HEADER_SIZE)
+    {
+        return TRUNCATED;
+    }
+    iUdp.read(header, DNS_HEADER_SIZE);
+
+    uint16_t header_flags = htons(*((uint16_t*)&header[2]));
+    // Check that it's a response to this request
+    if ( ( iRequestId != (*((uint16_t*)&header[0])) ) ||
+        ((header_flags & QUERY_RESPONSE_MASK) != (uint16_t)RESPONSE_FLAG) )
+    {
+        // Mark the entire packet as read
+        iUdp.flush();
+        return INVALID_RESPONSE;
+    }
+    // Check for any errors in the response (or in our request)
+    // although we don't do anything to get round these
+    if ( (header_flags & TRUNCATION_FLAG) || (header_flags & RESP_MASK) )
+    {
+        // Mark the entire packet as read
+        iUdp.flush();
+        return -5; //INVALID_RESPONSE;
+    }
+
+    // And make sure we've got (at least) one answer
+    uint16_t answerCount = htons(*((uint16_t*)&header[6]));
+    if (answerCount == 0 )
+    {
+        // Mark the entire packet as read
+        iUdp.flush();
+        return -6; //INVALID_RESPONSE;
+    }
+
+    // Skip over any questions
+    for (uint16_t i =0; i < htons(*((uint16_t*)&header[4])); i++)
+    {
+        // Skip over the name
+        uint8_t len;
+        do
+        {
+            iUdp.read(&len, sizeof(len));
+            if (len > 0)
+            {
+                // Don't need to actually read the data out for the string, just
+                // advance ptr to beyond it
+                while(len--)
+                {
+                    iUdp.read(); // we don't care about the returned byte
+                }
+            }
+        } while (len != 0);
+
+        // Now jump over the type and class
+        for (int i =0; i < 4; i++)
+        {
+            iUdp.read(); // we don't care about the returned byte
+        }
+    }
+
+    // Now we're up to the bit we're interested in, the answer
+    // There might be more than one answer (although we'll just use the first
+    // type A answer) and some authority and additional resource records but
+    // we're going to ignore all of them.
+
+    for (uint16_t i =0; i < answerCount; i++)
+    {
+        // Skip the name
+        uint8_t len;
+        do
+        {
+            iUdp.read(&len, sizeof(len));
+            if ((len & LABEL_COMPRESSION_MASK) == 0)
+            {
+                // It's just a normal label
+                if (len > 0)
+                {
+                    // And it's got a length
+                    // Don't need to actually read the data out for the string,
+                    // just advance ptr to beyond it
+                    while(len--)
+                    {
+                        iUdp.read(); // we don't care about the returned byte
+                    }
+                }
+            }
+            else
+            {
+                // This is a pointer to a somewhere else in the message for the
+                // rest of the name.  We don't care about the name, and RFC1035
+                // says that a name is either a sequence of labels ended with a
+                // 0 length octet or a pointer or a sequence of labels ending in
+                // a pointer.  Either way, when we get here we're at the end of
+                // the name
+                // Skip over the pointer
+                iUdp.read(); // we don't care about the returned byte
+                // And set len so that we drop out of the name loop
+                len = 0;
+            }
+        } while (len != 0);
+
+        // Check the type and class
+        uint16_t answerType;
+        uint16_t answerClass;
+        iUdp.read((uint8_t*)&answerType, sizeof(answerType));
+        iUdp.read((uint8_t*)&answerClass, sizeof(answerClass));
+
+        // Ignore the Time-To-Live as we don't do any caching
+        for (int i =0; i < TTL_SIZE; i++)
+        {
+            iUdp.read(); // we don't care about the returned byte
+        }
+
+        // And read out the length of this answer
+        // Don't need header_flags anymore, so we can reuse it here
+        iUdp.read((uint8_t*)&header_flags, sizeof(header_flags));
+
+        if ( (htons(answerType) == TYPE_A) && (htons(answerClass) == CLASS_IN) )
+        {
+            if (htons(header_flags) != 4)
+            {
+                // It's a weird size
+                // Mark the entire packet as read
+                iUdp.flush();
+                return -9;//INVALID_RESPONSE;
+            }
+            iUdp.read(aAddress.raw_address(), 4);
+            return SUCCESS;
+        }
+        else
+        {
+            // This isn't an answer type we're after, move onto the next one
+            for (uint16_t i =0; i < htons(header_flags); i++)
+            {
+                iUdp.read(); // we don't care about the returned byte
+            }
+        }
+    }
+
+    // Mark the entire packet as read
+    iUdp.flush();
+
+    // If we get here then we haven't found an answer
+    return -10;//INVALID_RESPONSE;
+}
+

Ethernet/Dns.h

@@ -0,0 +1,41 @@
+// Arduino DNS client for WizNet5100-based Ethernet shield
+// (c) Copyright 2009-2010 MCQN Ltd.
+// Released under Apache License, version 2.0
+
+#ifndef DNSClient_h
+#define DNSClient_h
+
+#include <EthernetUdp.h>
+
+class DNSClient
+{
+public:
+    // ctor
+    void begin(const IPAddress& aDNSServer);
+
+    /** Convert a numeric IP address string into a four-byte IP address.
+        @param aIPAddrString IP address to convert
+        @param aResult IPAddress structure to store the returned IP address
+        @result 1 if aIPAddrString was successfully converted to an IP address,
+                else error code
+    */
+    int inet_aton(const char *aIPAddrString, IPAddress& aResult);
+
+    /** Resolve the given hostname to an IP address.
+        @param aHostname Name to be resolved
+        @param aResult IPAddress structure to store the returned IP address
+        @result 1 if aIPAddrString was successfully converted to an IP address,
+                else error code
+    */
+    int getHostByName(const char* aHostname, IPAddress& aResult);
+
+protected:
+    uint16_t BuildRequest(const char* aName);
+    uint16_t ProcessResponse(uint16_t aTimeout, IPAddress& aAddress);
+
+    IPAddress iDNSServer;
+    uint16_t iRequestId;
+    EthernetUDP iUdp;
+};
+
+#endif

Ethernet/Ethernet.cpp

@@ -0,0 +1,136 @@
+#include "utility/w5100.h"
+#include "Ethernet.h"
+#include "Dhcp.h"
+
+// XXX: don't make assumptions about the value of MAX_SOCK_NUM.
+uint8_t EthernetClass::_state[MAX_SOCK_NUM] = { 
+  0, 0, 0, 0 };
+uint16_t EthernetClass::_server_port[MAX_SOCK_NUM] = { 
+  0, 0, 0, 0 };
+
+int EthernetClass::begin(uint8_t *mac_address)
+{
+  static DhcpClass s_dhcp;
+  _dhcp = &s_dhcp;
+
+
+  // Initialise the basic info
+  W5100.init();
+  SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+  W5100.setMACAddress(mac_address);
+  W5100.setIPAddress(IPAddress(0,0,0,0).raw_address());
+  SPI.endTransaction();
+
+  // Now try to get our config info from a DHCP server
+  int ret = _dhcp->beginWithDHCP(mac_address);
+  if(ret == 1)
+  {
+    // We've successfully found a DHCP server and got our configuration info, so set things
+    // accordingly
+    SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+    W5100.setIPAddress(_dhcp->getLocalIp().raw_address());
+    W5100.setGatewayIp(_dhcp->getGatewayIp().raw_address());
+    W5100.setSubnetMask(_dhcp->getSubnetMask().raw_address());
+    SPI.endTransaction();
+    _dnsServerAddress = _dhcp->getDnsServerIp();
+  }
+
+  return ret;
+}
+
+void EthernetClass::begin(uint8_t *mac_address, IPAddress local_ip)
+{
+  // Assume the DNS server will be the machine on the same network as the local IP
+  // but with last octet being '1'
+  IPAddress dns_server = local_ip;
+  dns_server[3] = 1;
+  begin(mac_address, local_ip, dns_server);
+}
+
+void EthernetClass::begin(uint8_t *mac_address, IPAddress local_ip, IPAddress dns_server)
+{
+  // Assume the gateway will be the machine on the same network as the local IP
+  // but with last octet being '1'
+  IPAddress gateway = local_ip;
+  gateway[3] = 1;
+  begin(mac_address, local_ip, dns_server, gateway);
+}
+
+void EthernetClass::begin(uint8_t *mac_address, IPAddress local_ip, IPAddress dns_server, IPAddress gateway)
+{
+  IPAddress subnet(255, 255, 255, 0);
+  begin(mac_address, local_ip, dns_server, gateway, subnet);
+}
+
+void EthernetClass::begin(uint8_t *mac, IPAddress local_ip, IPAddress dns_server, IPAddress gateway, IPAddress subnet)
+{
+  W5100.init();
+  SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+  W5100.setMACAddress(mac);
+  W5100.setIPAddress(local_ip.raw_address());
+  W5100.setGatewayIp(gateway.raw_address());
+  W5100.setSubnetMask(subnet.raw_address());
+  SPI.endTransaction();
+  _dnsServerAddress = dns_server;
+}
+
+int EthernetClass::maintain(){
+  int rc = DHCP_CHECK_NONE;
+  if(_dhcp != NULL){
+    //we have a pointer to dhcp, use it
+    rc = _dhcp->checkLease();
+    switch ( rc ){
+      case DHCP_CHECK_NONE:
+        //nothing done
+        break;
+      case DHCP_CHECK_RENEW_OK:
+      case DHCP_CHECK_REBIND_OK:
+        //we might have got a new IP.
+        SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+        W5100.setIPAddress(_dhcp->getLocalIp().raw_address());
+        W5100.setGatewayIp(_dhcp->getGatewayIp().raw_address());
+        W5100.setSubnetMask(_dhcp->getSubnetMask().raw_address());
+        SPI.endTransaction();
+        _dnsServerAddress = _dhcp->getDnsServerIp();
+        break;
+      default:
+        //this is actually a error, it will retry though
+        break;
+    }
+  }
+  return rc;
+}
+
+IPAddress EthernetClass::localIP()
+{
+  IPAddress ret;
+  SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+  W5100.getIPAddress(ret.raw_address());
+  SPI.endTransaction();
+  return ret;
+}
+
+IPAddress EthernetClass::subnetMask()
+{
+  IPAddress ret;
+  SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+  W5100.getSubnetMask(ret.raw_address());
+  SPI.endTransaction();
+  return ret;
+}
+
+IPAddress EthernetClass::gatewayIP()
+{
+  IPAddress ret;
+  SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+  W5100.getGatewayIp(ret.raw_address());
+  SPI.endTransaction();
+  return ret;
+}
+
+IPAddress EthernetClass::dnsServerIP()
+{
+  return _dnsServerAddress;
+}
+
+EthernetClass Ethernet;

Ethernet/Ethernet.h

@@ -0,0 +1,41 @@
+#ifndef ethernet_h
+#define ethernet_h
+
+#include <inttypes.h>
+//#include "w5100.h"
+#include "IPAddress.h"
+#include "EthernetClient.h"
+#include "EthernetServer.h"
+#include "Dhcp.h"
+
+#define MAX_SOCK_NUM 4
+
+class EthernetClass {
+private:
+  IPAddress _dnsServerAddress;
+  DhcpClass* _dhcp;
+public:
+  static uint8_t _state[MAX_SOCK_NUM];
+  static uint16_t _server_port[MAX_SOCK_NUM];
+  // Initialise the Ethernet shield to use the provided MAC address and gain the rest of the
+  // configuration through DHCP.
+  // Returns 0 if the DHCP configuration failed, and 1 if it succeeded
+  int begin(uint8_t *mac_address);
+  void begin(uint8_t *mac_address, IPAddress local_ip);
+  void begin(uint8_t *mac_address, IPAddress local_ip, IPAddress dns_server);
+  void begin(uint8_t *mac_address, IPAddress local_ip, IPAddress dns_server, IPAddress gateway);
+  void begin(uint8_t *mac_address, IPAddress local_ip, IPAddress dns_server, IPAddress gateway, IPAddress subnet);
+  int maintain();
+
+  IPAddress localIP();
+  IPAddress subnetMask();
+  IPAddress gatewayIP();
+  IPAddress dnsServerIP();
+
+  friend class EthernetClient;
+  friend class EthernetServer;
+};
+
+extern EthernetClass Ethernet;
+
+#endif

Ethernet/EthernetClient.cpp

@@ -0,0 +1,168 @@
+#include "utility/w5100.h"
+#include "utility/socket.h"
+
+extern "C" {
+  #include "string.h"
+}
+
+#include "Arduino.h"
+
+#include "Ethernet.h"
+#include "EthernetClient.h"
+#include "EthernetServer.h"
+#include "Dns.h"
+
+uint16_t EthernetClient::_srcport = 49152;      //Use IANA recommended ephemeral port range 49152-65535
+
+EthernetClient::EthernetClient() : _sock(MAX_SOCK_NUM) {
+}
+
+EthernetClient::EthernetClient(uint8_t sock) : _sock(sock) {
+}
+
+int EthernetClient::connect(const char* host, uint16_t port) {
+  // Look up the host first
+  int ret = 0;
+  DNSClient dns;
+  IPAddress remote_addr;
+
+  dns.begin(Ethernet.dnsServerIP());
+  ret = dns.getHostByName(host, remote_addr);
+  if (ret == 1) {
+    return connect(remote_addr, port);
+  } else {
+    return ret;
+  }
+}
+
+int EthernetClient::connect(IPAddress ip, uint16_t port) {
+  if (_sock != MAX_SOCK_NUM)
+    return 0;
+
+  for (int i = 0; i < MAX_SOCK_NUM; i++) {
+    uint8_t s = socketStatus(i);
+    if (s == SnSR::CLOSED || s == SnSR::FIN_WAIT || s == SnSR::CLOSE_WAIT) {
+      _sock = i;
+      break;
+    }
+  }
+
+  if (_sock == MAX_SOCK_NUM)
+    return 0;
+
+  _srcport++;
+  if (_srcport == 0) _srcport = 49152;          //Use IANA recommended ephemeral port range 49152-65535
+  socket(_sock, SnMR::TCP, _srcport, 0);
+
+  if (!::connect(_sock, rawIPAddress(ip), port)) {
+    _sock = MAX_SOCK_NUM;
+    return 0;
+  }
+
+  while (status() != SnSR::ESTABLISHED) {
+    delay(1);
+    if (status() == SnSR::CLOSED) {
+      _sock = MAX_SOCK_NUM;
+      return 0;
+    }
+  }
+
+  return 1;
+}
+
+size_t EthernetClient::write(uint8_t b) {
+  return write(&b, 1);
+}
+
+size_t EthernetClient::write(const uint8_t *buf, size_t size) {
+  if (_sock == MAX_SOCK_NUM) {
+    setWriteError();
+    return 0;
+  }
+  if (!send(_sock, buf, size)) {
+    setWriteError();
+    return 0;
+  }
+  return size;
+}
+
+int EthernetClient::available() {
+  if (_sock != MAX_SOCK_NUM)
+    return recvAvailable(_sock);
+  return 0;
+}
+
+int EthernetClient::read() {
+  uint8_t b;
+  if ( recv(_sock, &b, 1) > 0 )
+  {
+    // recv worked
+    return b;
+  }
+  else
+  {
+    // No data available
+    return -1;
+  }
+}
+
+int EthernetClient::read(uint8_t *buf, size_t size) {
+  return recv(_sock, buf, size);
+}
+
+int EthernetClient::peek() {
+  uint8_t b;
+  // Unlike recv, peek doesn't check to see if there's any data available, so we must
+  if (!available())
+    return -1;
+  ::peek(_sock, &b);
+  return b;
+}
+
+void EthernetClient::flush() {
+  ::flush(_sock);
+}
+
+void EthernetClient::stop() {
+  if (_sock == MAX_SOCK_NUM)
+    return;
+
+  // attempt to close the connection gracefully (send a FIN to other side)
+  disconnect(_sock);
+  unsigned long start = millis();
+
+  // wait a second for the connection to close
+  while (status() != SnSR::CLOSED && millis() - start < 1000)
+    delay(1);
+
+  // if it hasn't closed, close it forcefully
+  if (status() != SnSR::CLOSED)
+    close(_sock);
+
+  EthernetClass::_server_port[_sock] = 0;
+  _sock = MAX_SOCK_NUM;
+}
+
+uint8_t EthernetClient::connected() {
+  if (_sock == MAX_SOCK_NUM) return 0;
+  
+  uint8_t s = status();
+  return !(s == SnSR::LISTEN || s == SnSR::CLOSED || s == SnSR::FIN_WAIT ||
+    (s == SnSR::CLOSE_WAIT && !available()));
+}
+
+uint8_t EthernetClient::status() {
+  if (_sock == MAX_SOCK_NUM) return SnSR::CLOSED;
+  return socketStatus(_sock);
+}
+
+// the next function allows us to use the client returned by
+// EthernetServer::available() as the condition in an if-statement.
+
+EthernetClient::operator bool() {
+  return _sock != MAX_SOCK_NUM;
+}
+
+bool EthernetClient::operator==(const EthernetClient& rhs) {
+  return _sock == rhs._sock && _sock != MAX_SOCK_NUM && rhs._sock != MAX_SOCK_NUM;
+}

Ethernet/EthernetClient.h

@@ -0,0 +1,41 @@
+#ifndef ethernetclient_h
+#define ethernetclient_h
+#include "Arduino.h"	
+#include "Print.h"
+#include "Client.h"
+#include "IPAddress.h"
+
+class EthernetClient : public Client {
+
+public:
+  EthernetClient();
+  EthernetClient(uint8_t sock);
+
+  uint8_t status();
+  virtual int connect(IPAddress ip, uint16_t port);
+  virtual int connect(const char *host, uint16_t port);
+  virtual size_t write(uint8_t);
+  virtual size_t write(const uint8_t *buf, size_t size);
+  virtual int available();
+  virtual int read();
+  virtual int read(uint8_t *buf, size_t size);
+  virtual int peek();
+  virtual void flush();
+  virtual void stop();
+  virtual uint8_t connected();
+  virtual operator bool();
+  virtual bool operator==(const bool value) { return bool() == value; }
+  virtual bool operator!=(const bool value) { return bool() != value; }
+  virtual bool operator==(const EthernetClient&);
+  virtual bool operator!=(const EthernetClient& rhs) { return !this->operator==(rhs); };
+
+  friend class EthernetServer;
+  
+  using Print::write;
+
+private:
+  static uint16_t _srcport;
+  uint8_t _sock;
+};
+
+#endif

Ethernet/EthernetServer.cpp

@@ -0,0 +1,91 @@
+#include "utility/w5100.h"
+#include "utility/socket.h"
+extern "C" {
+#include "string.h"
+}
+
+#include "Ethernet.h"
+#include "EthernetClient.h"
+#include "EthernetServer.h"
+
+EthernetServer::EthernetServer(uint16_t port)
+{
+  _port = port;
+}
+
+void EthernetServer::begin()
+{
+  for (int sock = 0; sock < MAX_SOCK_NUM; sock++) {
+    EthernetClient client(sock);
+    if (client.status() == SnSR::CLOSED) {
+      socket(sock, SnMR::TCP, _port, 0);
+      listen(sock);
+      EthernetClass::_server_port[sock] = _port;
+      break;
+    }
+  }  
+}
+
+void EthernetServer::accept()
+{
+  int listening = 0;
+
+  for (int sock = 0; sock < MAX_SOCK_NUM; sock++) {
+    EthernetClient client(sock);
+
+    if (EthernetClass::_server_port[sock] == _port) {
+      if (client.status() == SnSR::LISTEN) {
+        listening = 1;
+      } 
+      else if (client.status() == SnSR::CLOSE_WAIT && !client.available()) {
+        client.stop();
+      }
+    } 
+  }
+
+  if (!listening) {
+    begin();
+  }
+}
+
+EthernetClient EthernetServer::available()
+{
+  accept();
+
+  for (int sock = 0; sock < MAX_SOCK_NUM; sock++) {
+    EthernetClient client(sock);
+    if (EthernetClass::_server_port[sock] == _port &&
+        (client.status() == SnSR::ESTABLISHED ||
+         client.status() == SnSR::CLOSE_WAIT)) {
+      if (client.available()) {
+        // XXX: don't always pick the lowest numbered socket.
+        return client;
+      }
+    }
+  }
+
+  return EthernetClient(MAX_SOCK_NUM);
+}
+
+size_t EthernetServer::write(uint8_t b) 
+{
+  return write(&b, 1);
+}
+
+size_t EthernetServer::write(const uint8_t *buffer, size_t size) 
+{
+  size_t n = 0;
+  
+  accept();
+
+  for (int sock = 0; sock < MAX_SOCK_NUM; sock++) {
+    EthernetClient client(sock);
+
+    if (EthernetClass::_server_port[sock] == _port &&
+      client.status() == SnSR::ESTABLISHED) {
+      n += client.write(buffer, size);
+    }
+  }
+  
+  return n;
+}

Ethernet/EthernetServer.h

@@ -0,0 +1,22 @@
+#ifndef ethernetserver_h
+#define ethernetserver_h
+
+#include "Server.h"
+
+class EthernetClient;
+
+class EthernetServer : 
+public Server {
+private:
+  uint16_t _port;
+  void accept();
+public:
+  EthernetServer(uint16_t);
+  EthernetClient available();
+  virtual void begin();
+  virtual size_t write(uint8_t);
+  virtual size_t write(const uint8_t *buf, size_t size);
+  using Print::write;
+};
+
+#endif

Ethernet/EthernetUdp.cpp

@@ -0,0 +1,218 @@
+/*
+ *  Udp.cpp: Library to send/receive UDP packets with the Arduino ethernet shield.
+ *  This version only offers minimal wrapping of socket.c/socket.h
+ *  Drop Udp.h/.cpp into the Ethernet library directory at hardware/libraries/Ethernet/ 
+ *
+ * MIT License:
+ * Copyright (c) 2008 Bjoern Hartmann
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * bjoern@cs.stanford.edu 12/30/2008
+ */
+
+#include "utility/w5100.h"
+#include "utility/socket.h"
+#include "Ethernet.h"
+#include "Udp.h"
+#include "Dns.h"
+
+/* Constructor */
+EthernetUDP::EthernetUDP() : _sock(MAX_SOCK_NUM) {}
+
+/* Start EthernetUDP socket, listening at local port PORT */
+uint8_t EthernetUDP::begin(uint16_t port) {
+  if (_sock != MAX_SOCK_NUM)
+    return 0;
+
+  for (int i = 0; i < MAX_SOCK_NUM; i++) {
+    uint8_t s = socketStatus(i);
+    if (s == SnSR::CLOSED || s == SnSR::FIN_WAIT) {
+      _sock = i;
+      break;
+    }
+  }
+
+  if (_sock == MAX_SOCK_NUM)
+    return 0;
+
+  _port = port;
+  _remaining = 0;
+  socket(_sock, SnMR::UDP, _port, 0);
+
+  return 1;
+}
+
+/* return number of bytes available in the current packet,
+   will return zero if parsePacket hasn't been called yet */
+int EthernetUDP::available() {
+  return _remaining;
+}
+
+/* Release any resources being used by this EthernetUDP instance */
+void EthernetUDP::stop()
+{
+  if (_sock == MAX_SOCK_NUM)
+    return;
+
+  close(_sock);
+
+  EthernetClass::_server_port[_sock] = 0;
+  _sock = MAX_SOCK_NUM;
+}
+
+int EthernetUDP::beginPacket(const char *host, uint16_t port)
+{
+  // Look up the host first
+  int ret = 0;
+  DNSClient dns;
+  IPAddress remote_addr;
+
+  dns.begin(Ethernet.dnsServerIP());
+  ret = dns.getHostByName(host, remote_addr);
+  if (ret == 1) {
+    return beginPacket(remote_addr, port);
+  } else {
+    return ret;
+  }
+}
+
+int EthernetUDP::beginPacket(IPAddress ip, uint16_t port)
+{
+  _offset = 0;
+  return startUDP(_sock, rawIPAddress(ip), port);
+}
+
+int EthernetUDP::endPacket()
+{
+  return sendUDP(_sock);
+}
+
+size_t EthernetUDP::write(uint8_t byte)
+{
+  return write(&byte, 1);
+}
+
+size_t EthernetUDP::write(const uint8_t *buffer, size_t size)
+{
+  uint16_t bytes_written = bufferData(_sock, _offset, buffer, size);
+  _offset += bytes_written;
+  return bytes_written;
+}
+
+int EthernetUDP::parsePacket()
+{
+  // discard any remaining bytes in the last packet
+  flush();
+
+  if (recvAvailable(_sock) > 0)
+  {
+    //HACK - hand-parse the UDP packet using TCP recv method
+    uint8_t tmpBuf[8];
+    int ret =0; 
+    //read 8 header bytes and get IP and port from it
+    ret = recv(_sock,tmpBuf,8);
+    if (ret > 0)
+    {
+      _remoteIP = tmpBuf;
+      _remotePort = tmpBuf[4];
+      _remotePort = (_remotePort << 8) + tmpBuf[5];
+      _remaining = tmpBuf[6];
+      _remaining = (_remaining << 8) + tmpBuf[7];
+
+      // When we get here, any remaining bytes are the data
+      ret = _remaining;
+    }
+    return ret;
+  }
+  // There aren't any packets available
+  return 0;
+}
+
+int EthernetUDP::read()
+{
+  uint8_t byte;
+
+  if ((_remaining > 0) && (recv(_sock, &byte, 1) > 0))
+  {
+    // We read things without any problems
+    _remaining--;
+    return byte;
+  }
+
+  // If we get here, there's no data available
+  return -1;
+}
+
+int EthernetUDP::read(unsigned char* buffer, size_t len)
+{
+
+  if (_remaining > 0)
+  {
+
+    int got;
+
+    if (_remaining <= len)
+    {
+      // data should fit in the buffer
+      got = recv(_sock, buffer, _remaining);
+    }
+    else
+    {
+      // too much data for the buffer, 
+      // grab as much as will fit
+      got = recv(_sock, buffer, len);
+    }
+
+    if (got > 0)
+    {
+      _remaining -= got;
+      return got;
+    }
+
+  }
+
+  // If we get here, there's no data available or recv failed
+  return -1;
+
+}
+
+int EthernetUDP::peek()
+{
+  uint8_t b;
+  // Unlike recv, peek doesn't check to see if there's any data available, so we must.
+  // If the user hasn't called parsePacket yet then return nothing otherwise they
+  // may get the UDP header
+  if (!_remaining)
+    return -1;
+  ::peek(_sock, &b);
+  return b;
+}
+
+void EthernetUDP::flush()
+{
+  // could this fail (loop endlessly) if _remaining > 0 and recv in read fails?
+  // should only occur if recv fails after telling us the data is there, lets
+  // hope the w5100 always behaves :)
+
+  while (_remaining)
+  {
+    read();
+  }
+}
+

Ethernet/EthernetUdp.h

@@ -0,0 +1,99 @@
+/*
+ *  Udp.cpp: Library to send/receive UDP packets with the Arduino ethernet shield.
+ *  This version only offers minimal wrapping of socket.c/socket.h
+ *  Drop Udp.h/.cpp into the Ethernet library directory at hardware/libraries/Ethernet/ 
+ *
+ * NOTE: UDP is fast, but has some important limitations (thanks to Warren Gray for mentioning these)
+ * 1) UDP does not guarantee the order in which assembled UDP packets are received. This
+ * might not happen often in practice, but in larger network topologies, a UDP
+ * packet can be received out of sequence. 
+ * 2) UDP does not guard against lost packets - so packets *can* disappear without the sender being
+ * aware of it. Again, this may not be a concern in practice on small local networks.
+ * For more information, see http://www.cafeaulait.org/course/week12/35.html
+ *
+ * MIT License:
+ * Copyright (c) 2008 Bjoern Hartmann
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * bjoern@cs.stanford.edu 12/30/2008
+ */
+
+#ifndef ethernetudp_h
+#define ethernetudp_h
+
+#include <Udp.h>
+
+#define UDP_TX_PACKET_MAX_SIZE 24
+
+class EthernetUDP : public UDP {
+private:
+  uint8_t _sock;  // socket ID for Wiz5100
+  uint16_t _port; // local port to listen on
+  IPAddress _remoteIP; // remote IP address for the incoming packet whilst it's being processed
+  uint16_t _remotePort; // remote port for the incoming packet whilst it's being processed
+  uint16_t _offset; // offset into the packet being sent
+  uint16_t _remaining; // remaining bytes of incoming packet yet to be processed
+
+public:
+  EthernetUDP();  // Constructor
+  virtual uint8_t begin(uint16_t);	// initialize, start listening on specified port. Returns 1 if successful, 0 if there are no sockets available to use
+  virtual void stop();  // Finish with the UDP socket
+
+  // Sending UDP packets
+  
+  // Start building up a packet to send to the remote host specific in ip and port
+  // Returns 1 if successful, 0 if there was a problem with the supplied IP address or port
+  virtual int beginPacket(IPAddress ip, uint16_t port);
+  // Start building up a packet to send to the remote host specific in host and port
+  // Returns 1 if successful, 0 if there was a problem resolving the hostname or port
+  virtual int beginPacket(const char *host, uint16_t port);
+  // Finish off this packet and send it
+  // Returns 1 if the packet was sent successfully, 0 if there was an error
+  virtual int endPacket();
+  // Write a single byte into the packet
+  virtual size_t write(uint8_t);
+  // Write size bytes from buffer into the packet
+  virtual size_t write(const uint8_t *buffer, size_t size);
+  
+  using Print::write;
+
+  // Start processing the next available incoming packet
+  // Returns the size of the packet in bytes, or 0 if no packets are available
+  virtual int parsePacket();
+  // Number of bytes remaining in the current packet
+  virtual int available();
+  // Read a single byte from the current packet
+  virtual int read();
+  // Read up to len bytes from the current packet and place them into buffer
+  // Returns the number of bytes read, or 0 if none are available
+  virtual int read(unsigned char* buffer, size_t len);
+  // Read up to len characters from the current packet and place them into buffer
+  // Returns the number of characters read, or 0 if none are available
+  virtual int read(char* buffer, size_t len) { return read((unsigned char*)buffer, len); };
+  // Return the next byte from the current packet without moving on to the next byte
+  virtual int peek();
+  virtual void flush();	// Finish reading the current packet
+
+  // Return the IP address of the host who sent the current incoming packet
+  virtual IPAddress remoteIP() { return _remoteIP; };
+  // Return the port of the host who sent the current incoming packet
+  virtual uint16_t remotePort() { return _remotePort; };
+};
+
+#endif

Ethernet/utility/socket.cpp

@@ -0,0 +1,469 @@
+#include "utility/w5100.h"
+#include "utility/socket.h"
+
+static uint16_t local_port;
+
+/**
+ * @brief	This Socket function initialize the channel in perticular mode, and set the port and wait for W5100 done it.
+ * @return 	1 for success else 0.
+ */
+uint8_t socket(SOCKET s, uint8_t protocol, uint16_t port, uint8_t flag)
+{
+  if ((protocol == SnMR::TCP) || (protocol == SnMR::UDP) || (protocol == SnMR::IPRAW) || (protocol == SnMR::MACRAW) || (protocol == SnMR::PPPOE))
+  {
+    close(s);
+    SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+    W5100.writeSnMR(s, protocol | flag);
+    if (port != 0) {
+      W5100.writeSnPORT(s, port);
+    } 
+    else {
+      local_port++; // if don't set the source port, set local_port number.
+      W5100.writeSnPORT(s, local_port);
+    }
+
+    W5100.execCmdSn(s, Sock_OPEN);
+    SPI.endTransaction();
+    return 1;
+  }
+
+  return 0;
+}
+
+
+uint8_t socketStatus(SOCKET s)
+{
+  SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+  uint8_t status = W5100.readSnSR(s);
+  SPI.endTransaction();
+  return status;
+}
+
+
+/**
+ * @brief	This function close the socket and parameter is "s" which represent the socket number
+ */
+void close(SOCKET s)
+{
+  SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+  W5100.execCmdSn(s, Sock_CLOSE);
+  W5100.writeSnIR(s, 0xFF);
+  SPI.endTransaction();
+}
+
+
+/**
+ * @brief	This function established  the connection for the channel in passive (server) mode. This function waits for the request from the peer.
+ * @return	1 for success else 0.
+ */
+uint8_t listen(SOCKET s)
+{
+  SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+  if (W5100.readSnSR(s) != SnSR::INIT) {
+    SPI.endTransaction();
+    return 0;
+  }
+  W5100.execCmdSn(s, Sock_LISTEN);
+  SPI.endTransaction();
+  return 1;
+}
+
+
+/**
+ * @brief	This function established  the connection for the channel in Active (client) mode. 
+ * 		This function waits for the untill the connection is established.
+ * 		
+ * @return	1 for success else 0.
+ */
+uint8_t connect(SOCKET s, uint8_t * addr, uint16_t port)
+{
+  if 
+    (
+  ((addr[0] == 0xFF) && (addr[1] == 0xFF) && (addr[2] == 0xFF) && (addr[3] == 0xFF)) ||
+    ((addr[0] == 0x00) && (addr[1] == 0x00) && (addr[2] == 0x00) && (addr[3] == 0x00)) ||
+    (port == 0x00) 
+    ) 
+    return 0;
+
+  // set destination IP
+  SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+  W5100.writeSnDIPR(s, addr);
+  W5100.writeSnDPORT(s, port);
+  W5100.execCmdSn(s, Sock_CONNECT);
+  SPI.endTransaction();
+
+  return 1;
+}
+
+
+
+/**
+ * @brief	This function used for disconnect the socket and parameter is "s" which represent the socket number
+ * @return	1 for success else 0.
+ */
+void disconnect(SOCKET s)
+{
+  SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+  W5100.execCmdSn(s, Sock_DISCON);
+  SPI.endTransaction();
+}
+
+
+/**
+ * @brief	This function used to send the data in TCP mode
+ * @return	1 for success else 0.
+ */
+uint16_t send(SOCKET s, const uint8_t * buf, uint16_t len)
+{
+  uint8_t status=0;
+  uint16_t ret=0;
+  uint16_t freesize=0;
+
+  if (len > W5100.SSIZE) 
+    ret = W5100.SSIZE; // check size not to exceed MAX size.
+  else 
+    ret = len;
+
+  // if freebuf is available, start.
+  do 
+  {
+    SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+    freesize = W5100.getTXFreeSize(s);
+    status = W5100.readSnSR(s);
+    SPI.endTransaction();
+    if ((status != SnSR::ESTABLISHED) && (status != SnSR::CLOSE_WAIT))
+    {
+      ret = 0; 
+      break;
+    }
+    yield();
+  } 
+  while (freesize < ret);
+
+  // copy data
+  SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+  W5100.send_data_processing(s, (uint8_t *)buf, ret);
+  W5100.execCmdSn(s, Sock_SEND);
+
+  /* +2008.01 bj */
+  while ( (W5100.readSnIR(s) & SnIR::SEND_OK) != SnIR::SEND_OK ) 
+  {
+    /* m2008.01 [bj] : reduce code */
+    if ( W5100.readSnSR(s) == SnSR::CLOSED )
+    {
+      SPI.endTransaction();
+      close(s);
+      return 0;
+    }
+    SPI.endTransaction();
+    yield();
+    SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+  }
+  /* +2008.01 bj */
+  W5100.writeSnIR(s, SnIR::SEND_OK);
+  SPI.endTransaction();
+  return ret;
+}
+
+
+/**
+ * @brief	This function is an application I/F function which is used to receive the data in TCP mode.
+ * 		It continues to wait for data as much as the application wants to receive.
+ * 		
+ * @return	received data size for success else -1.
+ */
+int16_t recv(SOCKET s, uint8_t *buf, int16_t len)
+{
+  // Check how much data is available
+  SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+  int16_t ret = W5100.getRXReceivedSize(s);
+  if ( ret == 0 )
+  {
+    // No data available.
+    uint8_t status = W5100.readSnSR(s);
+    if ( status == SnSR::LISTEN || status == SnSR::CLOSED || status == SnSR::CLOSE_WAIT )
+    {
+      // The remote end has closed its side of the connection, so this is the eof state
+      ret = 0;
+    }
+    else
+    {
+      // The connection is still up, but there's no data waiting to be read
+      ret = -1;
+    }
+  }
+  else if (ret > len)
+  {
+    ret = len;
+  }
+
+  if ( ret > 0 )
+  {
+    W5100.recv_data_processing(s, buf, ret);
+    W5100.execCmdSn(s, Sock_RECV);
+  }
+  SPI.endTransaction();
+  return ret;
+}
+
+
+int16_t recvAvailable(SOCKET s)
+{
+  SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+  int16_t ret = W5100.getRXReceivedSize(s);
+  SPI.endTransaction();
+  return ret;
+}
+
+
+/**
+ * @brief	Returns the first byte in the receive queue (no checking)
+ * 		
+ * @return
+ */
+uint16_t peek(SOCKET s, uint8_t *buf)
+{
+  SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+  W5100.recv_data_processing(s, buf, 1, 1);
+  SPI.endTransaction();
+  return 1;
+}
+
+
+/**
+ * @brief	This function is an application I/F function which is used to send the data for other then TCP mode. 
+ * 		Unlike TCP transmission, The peer's destination address and the port is needed.
+ * 		
+ * @return	This function return send data size for success else -1.
+ */
+uint16_t sendto(SOCKET s, const uint8_t *buf, uint16_t len, uint8_t *addr, uint16_t port)
+{
+  uint16_t ret=0;
+
+  if (len > W5100.SSIZE) ret = W5100.SSIZE; // check size not to exceed MAX size.
+  else ret = len;
+
+  if
+    (
+  ((addr[0] == 0x00) && (addr[1] == 0x00) && (addr[2] == 0x00) && (addr[3] == 0x00)) ||
+    ((port == 0x00)) ||(ret == 0)
+    ) 
+  {
+    /* +2008.01 [bj] : added return value */
+    ret = 0;
+  }
+  else
+  {
+    SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+    W5100.writeSnDIPR(s, addr);
+    W5100.writeSnDPORT(s, port);
+
+    // copy data
+    W5100.send_data_processing(s, (uint8_t *)buf, ret);
+    W5100.execCmdSn(s, Sock_SEND);
+
+    /* +2008.01 bj */
+    while ( (W5100.readSnIR(s) & SnIR::SEND_OK) != SnIR::SEND_OK ) 
+    {
+      if (W5100.readSnIR(s) & SnIR::TIMEOUT)
+      {
+        /* +2008.01 [bj]: clear interrupt */
+        W5100.writeSnIR(s, (SnIR::SEND_OK | SnIR::TIMEOUT)); /* clear SEND_OK & TIMEOUT */
+        SPI.endTransaction();
+        return 0;
+      }
+      SPI.endTransaction();
+      yield();
+      SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+    }
+
+    /* +2008.01 bj */
+    W5100.writeSnIR(s, SnIR::SEND_OK);
+    SPI.endTransaction();
+  }
+  return ret;
+}
+
+
+/**
+ * @brief	This function is an application I/F function which is used to receive the data in other then
+ * 	TCP mode. This function is used to receive UDP, IP_RAW and MAC_RAW mode, and handle the header as well. 
+ * 	
+ * @return	This function return received data size for success else -1.
+ */
+uint16_t recvfrom(SOCKET s, uint8_t *buf, uint16_t len, uint8_t *addr, uint16_t *port)
+{
+  uint8_t head[8];
+  uint16_t data_len=0;
+  uint16_t ptr=0;
+
+  if ( len > 0 )
+  {
+    SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+    ptr = W5100.readSnRX_RD(s);
+    switch (W5100.readSnMR(s) & 0x07)
+    {
+    case SnMR::UDP :
+      W5100.read_data(s, ptr, head, 0x08);
+      ptr += 8;
+      // read peer's IP address, port number.
+      addr[0] = head[0];
+      addr[1] = head[1];
+      addr[2] = head[2];
+      addr[3] = head[3];
+      *port = head[4];
+      *port = (*port << 8) + head[5];
+      data_len = head[6];
+      data_len = (data_len << 8) + head[7];
+
+      W5100.read_data(s, ptr, buf, data_len); // data copy.
+      ptr += data_len;
+
+      W5100.writeSnRX_RD(s, ptr);
+      break;
+
+    case SnMR::IPRAW :
+      W5100.read_data(s, ptr, head, 0x06);
+      ptr += 6;
+
+      addr[0] = head[0];
+      addr[1] = head[1];
+      addr[2] = head[2];
+      addr[3] = head[3];
+      data_len = head[4];
+      data_len = (data_len << 8) + head[5];
+
+      W5100.read_data(s, ptr, buf, data_len); // data copy.
+      ptr += data_len;
+
+      W5100.writeSnRX_RD(s, ptr);
+      break;
+
+    case SnMR::MACRAW:
+      W5100.read_data(s, ptr, head, 2);
+      ptr+=2;
+      data_len = head[0];
+      data_len = (data_len<<8) + head[1] - 2;
+
+      W5100.read_data(s, ptr, buf, data_len);
+      ptr += data_len;
+      W5100.writeSnRX_RD(s, ptr);
+      break;
+
+    default :
+      break;
+    }
+    W5100.execCmdSn(s, Sock_RECV);
+    SPI.endTransaction();
+  }
+  return data_len;
+}
+
+/**
+ * @brief	Wait for buffered transmission to complete.
+ */
+void flush(SOCKET s) {
+  // TODO
+}
+
+uint16_t igmpsend(SOCKET s, const uint8_t * buf, uint16_t len)
+{
+  uint16_t ret=0;
+
+  if (len > W5100.SSIZE) 
+    ret = W5100.SSIZE; // check size not to exceed MAX size.
+  else 
+    ret = len;
+
+  if (ret == 0)
+    return 0;
+
+  SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+  W5100.send_data_processing(s, (uint8_t *)buf, ret);
+  W5100.execCmdSn(s, Sock_SEND);
+
+  while ( (W5100.readSnIR(s) & SnIR::SEND_OK) != SnIR::SEND_OK ) 
+  {
+    if (W5100.readSnIR(s) & SnIR::TIMEOUT)
+    {
+      /* in case of igmp, if send fails, then socket closed */
+      /* if you want change, remove this code. */
+      SPI.endTransaction();
+      close(s);
+      return 0;
+    }
+    SPI.endTransaction();
+    yield();
+    SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+  }
+
+  W5100.writeSnIR(s, SnIR::SEND_OK);
+  SPI.endTransaction();
+  return ret;
+}
+
+uint16_t bufferData(SOCKET s, uint16_t offset, const uint8_t* buf, uint16_t len)
+{
+  uint16_t ret =0;
+  SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+  if (len > W5100.getTXFreeSize(s))
+  {
+    ret = W5100.getTXFreeSize(s); // check size not to exceed MAX size.
+  }
+  else
+  {
+    ret = len;
+  }
+  W5100.send_data_processing_offset(s, offset, buf, ret);
+  SPI.endTransaction();
+  return ret;
+}
+
+int startUDP(SOCKET s, uint8_t* addr, uint16_t port)
+{
+  if
+    (
+     ((addr[0] == 0x00) && (addr[1] == 0x00) && (addr[2] == 0x00) && (addr[3] == 0x00)) ||
+     ((port == 0x00))
+    ) 
+  {
+    return 0;
+  }
+  else
+  {
+    SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+    W5100.writeSnDIPR(s, addr);
+    W5100.writeSnDPORT(s, port);
+    SPI.endTransaction();
+    return 1;
+  }
+}
+
+int sendUDP(SOCKET s)
+{
+  SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+  W5100.execCmdSn(s, Sock_SEND);
+		
+  /* +2008.01 bj */
+  while ( (W5100.readSnIR(s) & SnIR::SEND_OK) != SnIR::SEND_OK ) 
+  {
+    if (W5100.readSnIR(s) & SnIR::TIMEOUT)
+    {
+      /* +2008.01 [bj]: clear interrupt */
+      W5100.writeSnIR(s, (SnIR::SEND_OK|SnIR::TIMEOUT));
+      SPI.endTransaction();
+      return 0;
+    }
+    SPI.endTransaction();
+    yield();
+    SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+  }
+
+  /* +2008.01 bj */	
+  W5100.writeSnIR(s, SnIR::SEND_OK);
+  SPI.endTransaction();
+
+  /* Sent ok */
+  return 1;
+}
+

Ethernet/utility/socket.h

@@ -0,0 +1,44 @@
+#ifndef	_SOCKET_H_
+#define	_SOCKET_H_
+
+#include "utility/w5100.h"
+
+extern uint8_t socket(SOCKET s, uint8_t protocol, uint16_t port, uint8_t flag); // Opens a socket(TCP or UDP or IP_RAW mode)
+extern uint8_t socketStatus(SOCKET s);
+extern void close(SOCKET s); // Close socket
+extern uint8_t connect(SOCKET s, uint8_t * addr, uint16_t port); // Establish TCP connection (Active connection)
+extern void disconnect(SOCKET s); // disconnect the connection
+extern uint8_t listen(SOCKET s);	// Establish TCP connection (Passive connection)
+extern uint16_t send(SOCKET s, const uint8_t * buf, uint16_t len); // Send data (TCP)
+extern int16_t recv(SOCKET s, uint8_t * buf, int16_t len);	// Receive data (TCP)
+extern int16_t recvAvailable(SOCKET s);
+extern uint16_t peek(SOCKET s, uint8_t *buf);
+extern uint16_t sendto(SOCKET s, const uint8_t * buf, uint16_t len, uint8_t * addr, uint16_t port); // Send data (UDP/IP RAW)
+extern uint16_t recvfrom(SOCKET s, uint8_t * buf, uint16_t len, uint8_t * addr, uint16_t *port); // Receive data (UDP/IP RAW)
+extern void flush(SOCKET s); // Wait for transmission to complete
+
+extern uint16_t igmpsend(SOCKET s, const uint8_t * buf, uint16_t len);
+
+// Functions to allow buffered UDP send (i.e. where the UDP datagram is built up over a
+// number of calls before being sent
+/*
+  @brief This function sets up a UDP datagram, the data for which will be provided by one
+  or more calls to bufferData and then finally sent with sendUDP.
+  @return 1 if the datagram was successfully set up, or 0 if there was an error
+*/
+extern int startUDP(SOCKET s, uint8_t* addr, uint16_t port);
+/*
+  @brief This function copies up to len bytes of data from buf into a UDP datagram to be
+  sent later by sendUDP.  Allows datagrams to be built up from a series of bufferData calls.
+  @return Number of bytes successfully buffered
+*/
+uint16_t bufferData(SOCKET s, uint16_t offset, const uint8_t* buf, uint16_t len);
+/*
+  @brief Send a UDP datagram built up from a sequence of startUDP followed by one or more
+  calls to bufferData.
+  @return 1 if the datagram was successfully sent, or 0 if there was an error
+*/
+int sendUDP(SOCKET s);
+
+#endif
+/* _SOCKET_H_ */

Ethernet/utility/util.h

@@ -0,0 +1,14 @@
+#ifndef UTIL_H
+#define UTIL_H
+
+#define htons(x) ( ((x)<< 8 & 0xFF00) | \
+                   ((x)>> 8 & 0x00FF) )
+#define ntohs(x) htons(x)
+
+#define htonl(x) ( ((x)<<24 & 0xFF000000UL) | \
+                   ((x)<< 8 & 0x00FF0000UL) | \
+                   ((x)>> 8 & 0x0000FF00UL) | \
+                   ((x)>>24 & 0x000000FFUL) )
+#define ntohl(x) htonl(x)
+
+#endif

Ethernet/utility/w5100.cpp

@@ -0,0 +1,225 @@
+/*
+ * Copyright (c) 2010 by Cristian Maglie <c.maglie@arduino.cc>
+ *
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of either the GNU General Public License version 2
+ * or the GNU Lesser General Public License version 2.1, both as
+ * published by the Free Software Foundation.
+ */
+
+#include <stdio.h>
+#include <string.h>
+
+#include "utility/w5100.h"
+
+// W5100 controller instance
+W5100Class W5100;
+
+#define TX_RX_MAX_BUF_SIZE 2048
+#define TX_BUF 0x1100
+#define RX_BUF (TX_BUF + TX_RX_MAX_BUF_SIZE)
+
+#define TXBUF_BASE 0x4000
+#define RXBUF_BASE 0x6000
+
+void W5100Class::init(void)
+{
+  delay(300);
+
+#if defined(ARDUINO_ARCH_AVR)
+  SPI.begin();
+  initSS();
+#else
+  SPI.begin(SPI_CS);
+  // Set clock to 4Mhz (W5100 should support up to about 14Mhz)
+  SPI.setClockDivider(SPI_CS, 21);
+  SPI.setDataMode(SPI_CS, SPI_MODE0);
+#endif
+  SPI.beginTransaction(SPI_ETHERNET_SETTINGS);
+  writeMR(1<<RST);
+  writeTMSR(0x55);
+  writeRMSR(0x55);
+  SPI.endTransaction();
+
+  for (int i=0; i<MAX_SOCK_NUM; i++) {
+    SBASE[i] = TXBUF_BASE + SSIZE * i;
+    RBASE[i] = RXBUF_BASE + RSIZE * i;
+  }
+}
+
+uint16_t W5100Class::getTXFreeSize(SOCKET s)
+{
+  uint16_t val=0, val1=0;
+  do {
+    val1 = readSnTX_FSR(s);
+    if (val1 != 0)
+      val = readSnTX_FSR(s);
+  } 
+  while (val != val1);
+  return val;
+}
+
+uint16_t W5100Class::getRXReceivedSize(SOCKET s)
+{
+  uint16_t val=0,val1=0;
+  do {
+    val1 = readSnRX_RSR(s);
+    if (val1 != 0)
+      val = readSnRX_RSR(s);
+  } 
+  while (val != val1);
+  return val;
+}
+
+
+void W5100Class::send_data_processing(SOCKET s, const uint8_t *data, uint16_t len)
+{
+  // This is same as having no offset in a call to send_data_processing_offset
+  send_data_processing_offset(s, 0, data, len);
+}
+
+void W5100Class::send_data_processing_offset(SOCKET s, uint16_t data_offset, const uint8_t *data, uint16_t len)
+{
+  uint16_t ptr = readSnTX_WR(s);
+  ptr += data_offset;
+  uint16_t offset = ptr & SMASK;
+  uint16_t dstAddr = offset + SBASE[s];
+
+  if (offset + len > SSIZE) 
+  {
+    // Wrap around circular buffer
+    uint16_t size = SSIZE - offset;
+    write(dstAddr, data, size);
+    write(SBASE[s], data + size, len - size);
+  } 
+  else {
+    write(dstAddr, data, len);
+  }
+
+  ptr += len;
+  writeSnTX_WR(s, ptr);
+}
+
+
+void W5100Class::recv_data_processing(SOCKET s, uint8_t *data, uint16_t len, uint8_t peek)
+{
+  uint16_t ptr;
+  ptr = readSnRX_RD(s);
+  read_data(s, ptr, data, len);
+  if (!peek)
+  {
+    ptr += len;
+    writeSnRX_RD(s, ptr);
+  }
+}
+
+void W5100Class::read_data(SOCKET s, volatile uint16_t src, volatile uint8_t *dst, uint16_t len)
+{
+  uint16_t size;
+  uint16_t src_mask;
+  uint16_t src_ptr;
+
+  src_mask = src & RMASK;
+  src_ptr = RBASE[s] + src_mask;
+
+  if( (src_mask + len) > RSIZE ) 
+  {
+    size = RSIZE - src_mask;
+    read(src_ptr, (uint8_t *)dst, size);
+    dst += size;
+    read(RBASE[s], (uint8_t *) dst, len - size);
+  } 
+  else
+    read(src_ptr, (uint8_t *) dst, len);
+}
+
+
+uint8_t W5100Class::write(uint16_t _addr, uint8_t _data)
+{
+#if defined(ARDUINO_ARCH_AVR)
+  setSS();  
+  SPI.transfer(0xF0);
+  SPI.transfer(_addr >> 8);
+  SPI.transfer(_addr & 0xFF);
+  SPI.transfer(_data);
+  resetSS();
+#else
+  SPI.transfer(SPI_CS, 0xF0, SPI_CONTINUE);
+  SPI.transfer(SPI_CS, _addr >> 8, SPI_CONTINUE);
+  SPI.transfer(SPI_CS, _addr & 0xFF, SPI_CONTINUE);
+  SPI.transfer(SPI_CS, _data);
+#endif
+  return 1;
+}
+
+uint16_t W5100Class::write(uint16_t _addr, const uint8_t *_buf, uint16_t _len)
+{
+  for (uint16_t i=0; i<_len; i++)
+  {
+#if defined(ARDUINO_ARCH_AVR)
+    setSS();    
+    SPI.transfer(0xF0);
+    SPI.transfer(_addr >> 8);
+    SPI.transfer(_addr & 0xFF);
+    _addr++;
+    SPI.transfer(_buf[i]);
+    resetSS();
+#else
+	SPI.transfer(SPI_CS, 0xF0, SPI_CONTINUE);
+	SPI.transfer(SPI_CS, _addr >> 8, SPI_CONTINUE);
+	SPI.transfer(SPI_CS, _addr & 0xFF, SPI_CONTINUE);
+	SPI.transfer(SPI_CS, _buf[i]);
+    _addr++;
+#endif
+  }
+  return _len;
+}
+
+uint8_t W5100Class::read(uint16_t _addr)
+{
+#if defined(ARDUINO_ARCH_AVR)
+  setSS();  
+  SPI.transfer(0x0F);
+  SPI.transfer(_addr >> 8);
+  SPI.transfer(_addr & 0xFF);
+  uint8_t _data = SPI.transfer(0);
+  resetSS();
+#else
+  SPI.transfer(SPI_CS, 0x0F, SPI_CONTINUE);
+  SPI.transfer(SPI_CS, _addr >> 8, SPI_CONTINUE);
+  SPI.transfer(SPI_CS, _addr & 0xFF, SPI_CONTINUE);
+  uint8_t _data = SPI.transfer(SPI_CS, 0);
+#endif
+  return _data;
+}
+
+uint16_t W5100Class::read(uint16_t _addr, uint8_t *_buf, uint16_t _len)
+{
+  for (uint16_t i=0; i<_len; i++)
+  {
+#if defined(ARDUINO_ARCH_AVR)
+    setSS();
+    SPI.transfer(0x0F);
+    SPI.transfer(_addr >> 8);
+    SPI.transfer(_addr & 0xFF);
+    _addr++;
+    _buf[i] = SPI.transfer(0);
+    resetSS();
+#else
+	SPI.transfer(SPI_CS, 0x0F, SPI_CONTINUE);
+	SPI.transfer(SPI_CS, _addr >> 8, SPI_CONTINUE);
+	SPI.transfer(SPI_CS, _addr & 0xFF, SPI_CONTINUE);
+    _buf[i] = SPI.transfer(SPI_CS, 0);
+    _addr++;
+#endif
+  }
+  return _len;
+}
+
+void W5100Class::execCmdSn(SOCKET s, SockCMD _cmd) {
+  // Send command to socket
+  writeSnCR(s, _cmd);
+  // Wait for command to complete
+  while (readSnCR(s))
+    ;
+}

Ethernet/utility/w5100.h

@@ -0,0 +1,412 @@
+/*
+ * Copyright (c) 2010 by Cristian Maglie <c.maglie@arduino.cc>
+ *
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of either the GNU General Public License version 2
+ * or the GNU Lesser General Public License version 2.1, both as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef	W5100_H_INCLUDED
+#define	W5100_H_INCLUDED
+
+#include <SPI.h>
+
+#define SPI_CS 10
+
+#if defined(ARDUINO_ARCH_AVR)
+#define SPI_ETHERNET_SETTINGS SPISettings(4000000, MSBFIRST, SPI_MODE0)
+#else
+#define SPI_ETHERNET_SETTINGS SPI_CS,SPISettings(4000000, MSBFIRST, SPI_MODE0)
+#endif
+
+#define MAX_SOCK_NUM 4
+
+typedef uint8_t SOCKET;
+
+#define IDM_OR  0x8000
+#define IDM_AR0 0x8001
+#define IDM_AR1 0x8002
+#define IDM_DR  0x8003
+/*
+class MR {
+public:
+  static const uint8_t RST   = 0x80;
+  static const uint8_t PB    = 0x10;
+  static const uint8_t PPPOE = 0x08;
+  static const uint8_t LB    = 0x04;
+  static const uint8_t AI    = 0x02;
+  static const uint8_t IND   = 0x01;
+};
+*/
+/*
+class IR {
+public:
+  static const uint8_t CONFLICT = 0x80;
+  static const uint8_t UNREACH  = 0x40;
+  static const uint8_t PPPoE    = 0x20;
+  static const uint8_t SOCK0    = 0x01;
+  static const uint8_t SOCK1    = 0x02;
+  static const uint8_t SOCK2    = 0x04;
+  static const uint8_t SOCK3    = 0x08;
+  static inline uint8_t SOCK(SOCKET ch) { return (0x01 << ch); };
+};
+*/
+
+class SnMR {
+public:
+  static const uint8_t CLOSE  = 0x00;
+  static const uint8_t TCP    = 0x01;
+  static const uint8_t UDP    = 0x02;
+  static const uint8_t IPRAW  = 0x03;
+  static const uint8_t MACRAW = 0x04;
+  static const uint8_t PPPOE  = 0x05;
+  static const uint8_t ND     = 0x20;
+  static const uint8_t MULTI  = 0x80;
+};
+
+enum SockCMD {
+  Sock_OPEN      = 0x01,
+  Sock_LISTEN    = 0x02,
+  Sock_CONNECT   = 0x04,
+  Sock_DISCON    = 0x08,
+  Sock_CLOSE     = 0x10,
+  Sock_SEND      = 0x20,
+  Sock_SEND_MAC  = 0x21,
+  Sock_SEND_KEEP = 0x22,
+  Sock_RECV      = 0x40
+};
+
+/*class SnCmd {
+public:
+  static const uint8_t OPEN      = 0x01;
+  static const uint8_t LISTEN    = 0x02;
+  static const uint8_t CONNECT   = 0x04;
+  static const uint8_t DISCON    = 0x08;
+  static const uint8_t CLOSE     = 0x10;
+  static const uint8_t SEND      = 0x20;
+  static const uint8_t SEND_MAC  = 0x21;
+  static const uint8_t SEND_KEEP = 0x22;
+  static const uint8_t RECV      = 0x40;
+};
+*/
+
+class SnIR {
+public:
+  static const uint8_t SEND_OK = 0x10;
+  static const uint8_t TIMEOUT = 0x08;
+  static const uint8_t RECV    = 0x04;
+  static const uint8_t DISCON  = 0x02;
+  static const uint8_t CON     = 0x01;
+};
+
+class SnSR {
+public:
+  static const uint8_t CLOSED      = 0x00;
+  static const uint8_t INIT        = 0x13;
+  static const uint8_t LISTEN      = 0x14;
+  static const uint8_t SYNSENT     = 0x15;
+  static const uint8_t SYNRECV     = 0x16;
+  static const uint8_t ESTABLISHED = 0x17;
+  static const uint8_t FIN_WAIT    = 0x18;
+  static const uint8_t CLOSING     = 0x1A;
+  static const uint8_t TIME_WAIT   = 0x1B;
+  static const uint8_t CLOSE_WAIT  = 0x1C;
+  static const uint8_t LAST_ACK    = 0x1D;
+  static const uint8_t UDP         = 0x22;
+  static const uint8_t IPRAW       = 0x32;
+  static const uint8_t MACRAW      = 0x42;
+  static const uint8_t PPPOE       = 0x5F;
+};
+
+class IPPROTO {
+public:
+  static const uint8_t IP   = 0;
+  static const uint8_t ICMP = 1;
+  static const uint8_t IGMP = 2;
+  static const uint8_t GGP  = 3;
+  static const uint8_t TCP  = 6;
+  static const uint8_t PUP  = 12;
+  static const uint8_t UDP  = 17;
+  static const uint8_t IDP  = 22;
+  static const uint8_t ND   = 77;
+  static const uint8_t RAW  = 255;
+};
+
+class W5100Class {
+
+public:
+  void init();
+
+  /**
+   * @brief	This function is being used for copy the data form Receive buffer of the chip to application buffer.
+   * 
+   * It calculate the actual physical address where one has to read
+   * the data from Receive buffer. Here also take care of the condition while it exceed
+   * the Rx memory uper-bound of socket.
+   */
+  void read_data(SOCKET s, volatile uint16_t src, volatile uint8_t * dst, uint16_t len);
+  
+  /**
+   * @brief	 This function is being called by send() and sendto() function also. 
+   * 
+   * This function read the Tx write pointer register and after copy the data in buffer update the Tx write pointer
+   * register. User should read upper byte first and lower byte later to get proper value.
+   */
+  void send_data_processing(SOCKET s, const uint8_t *data, uint16_t len);
+  /**
+   * @brief A copy of send_data_processing that uses the provided ptr for the
+   *        write offset.  Only needed for the "streaming" UDP API, where
+   *        a single UDP packet is built up over a number of calls to
+   *        send_data_processing_ptr, because TX_WR doesn't seem to get updated
+   *        correctly in those scenarios
+   * @param ptr value to use in place of TX_WR.  If 0, then the value is read
+   *        in from TX_WR
+   * @return New value for ptr, to be used in the next call
+   */
+// FIXME Update documentation
+  void send_data_processing_offset(SOCKET s, uint16_t data_offset, const uint8_t *data, uint16_t len);
+
+  /**
+   * @brief	This function is being called by recv() also.
+   * 
+   * This function read the Rx read pointer register
+   * and after copy the data from receive buffer update the Rx write pointer register.
+   * User should read upper byte first and lower byte later to get proper value.
+   */
+  void recv_data_processing(SOCKET s, uint8_t *data, uint16_t len, uint8_t peek = 0);
+
+  inline void setGatewayIp(uint8_t *_addr);
+  inline void getGatewayIp(uint8_t *_addr);
+
+  inline void setSubnetMask(uint8_t *_addr);
+  inline void getSubnetMask(uint8_t *_addr);
+
+  inline void setMACAddress(uint8_t * addr);
+  inline void getMACAddress(uint8_t * addr);
+
+  inline void setIPAddress(uint8_t * addr);
+  inline void getIPAddress(uint8_t * addr);
+
+  inline void setRetransmissionTime(uint16_t timeout);
+  inline void setRetransmissionCount(uint8_t _retry);
+
+  void execCmdSn(SOCKET s, SockCMD _cmd);
+  
+  uint16_t getTXFreeSize(SOCKET s);
+  uint16_t getRXReceivedSize(SOCKET s);
+  
+
+  // W5100 Registers
+  // ---------------
+private:
+  static uint8_t write(uint16_t _addr, uint8_t _data);
+  static uint16_t write(uint16_t addr, const uint8_t *buf, uint16_t len);
+  static uint8_t read(uint16_t addr);
+  static uint16_t read(uint16_t addr, uint8_t *buf, uint16_t len);
+  
+#define __GP_REGISTER8(name, address)             \
+  static inline void write##name(uint8_t _data) { \
+    write(address, _data);                        \
+  }                                               \
+  static inline uint8_t read##name() {            \
+    return read(address);                         \
+  }
+#define __GP_REGISTER16(name, address)            \
+  static void write##name(uint16_t _data) {       \
+    write(address,   _data >> 8);                 \
+    write(address+1, _data & 0xFF);               \
+  }                                               \
+  static uint16_t read##name() {                  \
+    uint16_t res = read(address);                 \
+    res = (res << 8) + read(address + 1);         \
+    return res;                                   \
+  }
+#define __GP_REGISTER_N(name, address, size)      \
+  static uint16_t write##name(uint8_t *_buff) {   \
+    return write(address, _buff, size);           \
+  }                                               \
+  static uint16_t read##name(uint8_t *_buff) {    \
+    return read(address, _buff, size);            \
+  }
+
+public:
+  __GP_REGISTER8 (MR,     0x0000);    // Mode
+  __GP_REGISTER_N(GAR,    0x0001, 4); // Gateway IP address
+  __GP_REGISTER_N(SUBR,   0x0005, 4); // Subnet mask address
+  __GP_REGISTER_N(SHAR,   0x0009, 6); // Source MAC address
+  __GP_REGISTER_N(SIPR,   0x000F, 4); // Source IP address
+  __GP_REGISTER8 (IR,     0x0015);    // Interrupt
+  __GP_REGISTER8 (IMR,    0x0016);    // Interrupt Mask
+  __GP_REGISTER16(RTR,    0x0017);    // Timeout address
+  __GP_REGISTER8 (RCR,    0x0019);    // Retry count
+  __GP_REGISTER8 (RMSR,   0x001A);    // Receive memory size
+  __GP_REGISTER8 (TMSR,   0x001B);    // Transmit memory size
+  __GP_REGISTER8 (PATR,   0x001C);    // Authentication type address in PPPoE mode
+  __GP_REGISTER8 (PTIMER, 0x0028);    // PPP LCP Request Timer
+  __GP_REGISTER8 (PMAGIC, 0x0029);    // PPP LCP Magic Number
+  __GP_REGISTER_N(UIPR,   0x002A, 4); // Unreachable IP address in UDP mode
+  __GP_REGISTER16(UPORT,  0x002E);    // Unreachable Port address in UDP mode
+  
+#undef __GP_REGISTER8
+#undef __GP_REGISTER16
+#undef __GP_REGISTER_N
+
+  // W5100 Socket registers
+  // ----------------------
+private:
+  static inline uint8_t readSn(SOCKET _s, uint16_t _addr);
+  static inline uint8_t writeSn(SOCKET _s, uint16_t _addr, uint8_t _data);
+  static inline uint16_t readSn(SOCKET _s, uint16_t _addr, uint8_t *_buf, uint16_t len);
+  static inline uint16_t writeSn(SOCKET _s, uint16_t _addr, uint8_t *_buf, uint16_t len);
+
+  static const uint16_t CH_BASE = 0x0400;
+  static const uint16_t CH_SIZE = 0x0100;
+
+#define __SOCKET_REGISTER8(name, address)                    \
+  static inline void write##name(SOCKET _s, uint8_t _data) { \
+    writeSn(_s, address, _data);                             \
+  }                                                          \
+  static inline uint8_t read##name(SOCKET _s) {              \
+    return readSn(_s, address);                              \
+  }
+#define __SOCKET_REGISTER16(name, address)                   \
+  static void write##name(SOCKET _s, uint16_t _data) {       \
+    writeSn(_s, address,   _data >> 8);                      \
+    writeSn(_s, address+1, _data & 0xFF);                    \
+  }                                                          \
+  static uint16_t read##name(SOCKET _s) {                    \
+    uint16_t res = readSn(_s, address);                      \
+    uint16_t res2 = readSn(_s,address + 1);                  \
+    res = res << 8;                                          \
+    res2 = res2 & 0xFF;                                      \
+    res = res | res2;                                        \
+    return res;                                              \
+  }
+#define __SOCKET_REGISTER_N(name, address, size)             \
+  static uint16_t write##name(SOCKET _s, uint8_t *_buff) {   \
+    return writeSn(_s, address, _buff, size);                \
+  }                                                          \
+  static uint16_t read##name(SOCKET _s, uint8_t *_buff) {    \
+    return readSn(_s, address, _buff, size);                 \
+  }
+  
+public:
+  __SOCKET_REGISTER8(SnMR,        0x0000)        // Mode
+  __SOCKET_REGISTER8(SnCR,        0x0001)        // Command
+  __SOCKET_REGISTER8(SnIR,        0x0002)        // Interrupt
+  __SOCKET_REGISTER8(SnSR,        0x0003)        // Status
+  __SOCKET_REGISTER16(SnPORT,     0x0004)        // Source Port
+  __SOCKET_REGISTER_N(SnDHAR,     0x0006, 6)     // Destination Hardw Addr
+  __SOCKET_REGISTER_N(SnDIPR,     0x000C, 4)     // Destination IP Addr
+  __SOCKET_REGISTER16(SnDPORT,    0x0010)        // Destination Port
+  __SOCKET_REGISTER16(SnMSSR,     0x0012)        // Max Segment Size
+  __SOCKET_REGISTER8(SnPROTO,     0x0014)        // Protocol in IP RAW Mode
+  __SOCKET_REGISTER8(SnTOS,       0x0015)        // IP TOS
+  __SOCKET_REGISTER8(SnTTL,       0x0016)        // IP TTL
+  __SOCKET_REGISTER16(SnTX_FSR,   0x0020)        // TX Free Size
+  __SOCKET_REGISTER16(SnTX_RD,    0x0022)        // TX Read Pointer
+  __SOCKET_REGISTER16(SnTX_WR,    0x0024)        // TX Write Pointer
+  __SOCKET_REGISTER16(SnRX_RSR,   0x0026)        // RX Free Size
+  __SOCKET_REGISTER16(SnRX_RD,    0x0028)        // RX Read Pointer
+  __SOCKET_REGISTER16(SnRX_WR,    0x002A)        // RX Write Pointer (supported?)
+  
+#undef __SOCKET_REGISTER8
+#undef __SOCKET_REGISTER16
+#undef __SOCKET_REGISTER_N
+
+
+private:
+  static const uint8_t  RST = 7; // Reset BIT
+
+  static const int SOCKETS = 4;
+  static const uint16_t SMASK = 0x07FF; // Tx buffer MASK
+  static const uint16_t RMASK = 0x07FF; // Rx buffer MASK
+public:
+  static const uint16_t SSIZE = 2048; // Max Tx buffer size
+private:
+  static const uint16_t RSIZE = 2048; // Max Rx buffer size
+  uint16_t SBASE[SOCKETS]; // Tx buffer base address
+  uint16_t RBASE[SOCKETS]; // Rx buffer base address
+
+private:
+#if defined(ARDUINO_ARCH_AVR)
+#if defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)
+  inline static void initSS()    { DDRB  |=  _BV(4); };
+  inline static void setSS()     { PORTB &= ~_BV(4); };
+  inline static void resetSS()   { PORTB |=  _BV(4); };
+#elif defined(__AVR_ATmega32U4__)
+  inline static void initSS()    { DDRB  |=  _BV(6); };
+  inline static void setSS()     { PORTB &= ~_BV(6); };
+  inline static void resetSS()   { PORTB |=  _BV(6); }; 
+#elif defined(__AVR_AT90USB1286__) || defined(__AVR_AT90USB646__) || defined(__AVR_AT90USB162__)
+  inline static void initSS()    { DDRB  |=  _BV(0); };
+  inline static void setSS()     { PORTB &= ~_BV(0); };
+  inline static void resetSS()   { PORTB |=  _BV(0); }; 
+#else
+  inline static void initSS()    { DDRB  |=  _BV(2); };
+  inline static void setSS()     { PORTB &= ~_BV(2); };
+  inline static void resetSS()   { PORTB |=  _BV(2); };
+#endif
+#endif // ARDUINO_ARCH_AVR
+};
+
+extern W5100Class W5100;
+
+uint8_t W5100Class::readSn(SOCKET _s, uint16_t _addr) {
+  return read(CH_BASE + _s * CH_SIZE + _addr);
+}
+
+uint8_t W5100Class::writeSn(SOCKET _s, uint16_t _addr, uint8_t _data) {
+  return write(CH_BASE + _s * CH_SIZE + _addr, _data);
+}
+
+uint16_t W5100Class::readSn(SOCKET _s, uint16_t _addr, uint8_t *_buf, uint16_t _len) {
+  return read(CH_BASE + _s * CH_SIZE + _addr, _buf, _len);
+}
+
+uint16_t W5100Class::writeSn(SOCKET _s, uint16_t _addr, uint8_t *_buf, uint16_t _len) {
+  return write(CH_BASE + _s * CH_SIZE + _addr, _buf, _len);
+}
+
+void W5100Class::getGatewayIp(uint8_t *_addr) {
+  readGAR(_addr);
+}
+
+void W5100Class::setGatewayIp(uint8_t *_addr) {
+  writeGAR(_addr);
+}
+
+void W5100Class::getSubnetMask(uint8_t *_addr) {
+  readSUBR(_addr);
+}
+
+void W5100Class::setSubnetMask(uint8_t *_addr) {
+  writeSUBR(_addr);
+}
+
+void W5100Class::getMACAddress(uint8_t *_addr) {
+  readSHAR(_addr);
+}
+
+void W5100Class::setMACAddress(uint8_t *_addr) {
+  writeSHAR(_addr);
+}
+
+void W5100Class::getIPAddress(uint8_t *_addr) {
+  readSIPR(_addr);
+}
+
+void W5100Class::setIPAddress(uint8_t *_addr) {
+  writeSIPR(_addr);
+}
+
+void W5100Class::setRetransmissionTime(uint16_t _timeout) {
+  writeRTR(_timeout);
+}
+
+void W5100Class::setRetransmissionCount(uint8_t _retry) {
+  writeRCR(_retry);
+}
+
+#endif

MQTT/PubSubClient.cpp

@@ -0,0 +1,365 @@
+/*
+ PubSubClient.cpp - A simple client for MQTT.
+  Nicholas O'Leary
+  http://knolleary.net
+*/
+
+#include "PubSubClient.h"
+#include <string.h>
+
+PubSubClient::PubSubClient(Client& client) {
+   this->_client = &client;
+}
+
+PubSubClient::PubSubClient(uint8_t *ip, uint16_t port, void (*callback)(char*,uint8_t*,unsigned int), Client& client) {
+   this->_client = &client;
+   this->callback = callback;
+   this->ip = ip;
+   this->port = port;
+}
+
+PubSubClient::PubSubClient(char* domain, uint16_t port, void (*callback)(char*,uint8_t*,unsigned int), Client& client) {
+   this->_client = &client;
+   this->callback = callback;
+   this->domain = domain;
+   this->port = port;
+}
+
+boolean PubSubClient::connect(char *id) {
+   return connect(id,NULL,NULL,0,0,0,0);
+}
+
+boolean PubSubClient::connect(char *id, char *user, char *pass) {
+   return connect(id,user,pass,0,0,0,0);
+}
+
+boolean PubSubClient::connect(char *id, char* willTopic, uint8_t willQos, uint8_t willRetain, char* willMessage)
+{
+   return connect(id,NULL,NULL,willTopic,willQos,willRetain,willMessage);
+}
+
+boolean PubSubClient::connect(char *id, char *user, char *pass, char* willTopic, uint8_t willQos, uint8_t willRetain, char* willMessage) {
+//   if (!connected()) {
+   if (true) {
+      int result = 0;
+      
+      if (domain != NULL) {
+        result = _client->connect(this->domain, this->port);
+      } else {
+        result = _client->connect(this->ip, this->port);
+      }
+      
+      if (result) {
+         nextMsgId = 1;
+         uint8_t d[9] = {0x00,0x06,'M','Q','I','s','d','p',MQTTPROTOCOLVERSION};
+         // Leave room in the buffer for header and variable length field
+         uint16_t length = 5;
+         unsigned int j;
+         for (j = 0;j<9;j++) {
+            buffer[length++] = d[j];
+         }
+
+         uint8_t v;
+         if (willTopic) {
+            v = 0x06|(willQos<<3)|(willRetain<<5);
+         } else {
+            v = 0x02;
+         }
+
+         if(user != NULL) {
+            v = v|0x80;
+
+            if(pass != NULL) {
+               v = v|(0x80>>1);
+            }
+         }
+
+         buffer[length++] = v;
+
+         buffer[length++] = ((MQTT_KEEPALIVE) >> 8);
+         buffer[length++] = ((MQTT_KEEPALIVE) & 0xFF);
+         length = writeString(id,buffer,length);
+         if (willTopic) {
+            length = writeString(willTopic,buffer,length);
+            length = writeString(willMessage,buffer,length);
+         }
+
+         if(user != NULL) {
+            length = writeString(user,buffer,length);
+            if(pass != NULL) {
+               length = writeString(pass,buffer,length);
+            }
+         }
+         
+         write(MQTTCONNECT,buffer,length-5);
+         
+         lastInActivity = lastOutActivity = millis();
+         
+         while (!_client->available()) {
+            unsigned long t = millis();
+            if (t-lastInActivity > MQTT_KEEPALIVE*1000UL) {
+               _client->stop();
+               return false;
+            }
+         }
+         uint16_t len = readPacket();
+         
+         if (len == 4 && buffer[3] == 0) {
+            lastInActivity = millis();
+            pingOutstanding = false;
+            return true;
+         }
+      }
+      _client->stop();
+   }
+   return false;
+}
+
+uint8_t PubSubClient::readByte() {
+   while(!_client->available()) {}
+   return _client->read();
+}
+
+uint16_t PubSubClient::readPacket() {
+   uint16_t len = 0;
+   buffer[len++] = readByte();
+   uint8_t multiplier = 1;
+   uint16_t length = 0;
+   uint8_t digit = 0;
+   do {
+      digit = readByte();
+      buffer[len++] = digit;
+      length += (digit & 127) * multiplier;
+      multiplier *= 128;
+   } while ((digit & 128) != 0);
+   
+   for (uint16_t i = 0;i<length;i++)
+   {
+      if (len < MQTT_MAX_PACKET_SIZE) {
+         buffer[len++] = readByte();
+      } else {
+         readByte();
+         len = 0; // This will cause the packet to be ignored.
+      }
+   }
+
+   return len;
+}
+
+boolean PubSubClient::loop() {
+   if (connected()) {
+      unsigned long t = millis();
+      if ((t - lastInActivity > MQTT_KEEPALIVE*1000UL) || (t - lastOutActivity > MQTT_KEEPALIVE*1000UL)) {
+         if (pingOutstanding) {
+            _client->stop();
+            return false;
+         } else {
+            buffer[0] = MQTTPINGREQ;
+            buffer[1] = 0;
+            _client->write(buffer,2);
+            lastOutActivity = t;
+            lastInActivity = t;
+            pingOutstanding = true;
+         }
+      }
+      if (_client->available()) {
+         uint16_t len = readPacket();
+         if (len > 0) {
+            lastInActivity = t;
+            uint8_t type = buffer[0]&0xF0;
+            if (type == MQTTPUBLISH) {
+               if (callback) {
+                  uint16_t tl = (buffer[2]<<8)+buffer[3];
+                  char topic[tl+1];
+                  for (uint16_t i=0;i<tl;i++) {
+                     topic[i] = buffer[4+i];
+                  }
+                  topic[tl] = 0;
+                  // ignore msgID - only support QoS 0 subs
+                  uint8_t *payload = buffer+4+tl;
+                  callback(topic,payload,len-4-tl);
+               }
+            } else if (type == MQTTPINGREQ) {
+               buffer[0] = MQTTPINGRESP;
+               buffer[1] = 0;
+               _client->write(buffer,2);
+            } else if (type == MQTTPINGRESP) {
+               pingOutstanding = false;
+            }
+         }
+      }
+      return true;
+   }
+   return false;
+}
+
+boolean PubSubClient::publish(char* topic, char* payload) {
+   return publish(topic,(uint8_t*)payload,strlen(payload),false);
+}
+
+boolean PubSubClient::publish(char* topic, uint8_t* payload, unsigned int plength) {
+   return publish(topic, payload, plength, false);
+}
+
+boolean PubSubClient::publish(char* topic, uint8_t* payload, unsigned int plength, boolean retained) {
+   if (connected()) {
+      // Leave room in the buffer for header and variable length field
+      uint16_t length = 5;
+      length = writeString(topic,buffer,length);
+      uint16_t i;
+      for (i=0;i<plength;i++) {
+         buffer[length++] = payload[i];
+      }
+      uint8_t header = MQTTPUBLISH;
+      if (retained) {
+         header |= 1;
+      }
+      // Serial.print("pub len: "); Serial.println(length-5);
+      return write(header,buffer,length-5);
+   } else {
+     // Serial.println("connection lost");
+   }
+   return false;
+}
+
+boolean PubSubClient::publish_P(char* topic, uint8_t* PROGMEM payload, unsigned int plength, boolean retained) {
+   uint8_t llen = 0;
+   uint8_t digit;
+   int rc;
+   uint16_t tlen;
+   int pos = 0;
+   int i;
+   uint8_t header;
+   unsigned int len;
+   
+   if (!connected()) {
+      return false;
+   }
+   
+   tlen = strlen(topic);
+   
+   header = MQTTPUBLISH;
+   if (retained) {
+      header |= 1;
+   }
+   buffer[pos++] = header;
+   len = plength + 2 + tlen;
+   do {
+      digit = len % 128;
+      len = len / 128;
+      if (len > 0) {
+         digit |= 0x80;
+      }
+      buffer[pos++] = digit;
+      llen++;
+   } while(len>0);
+   
+   pos = writeString(topic,buffer,pos);
+   
+   rc += _client->write(buffer,pos);
+   
+   for (i=0;i<plength;i++) {
+      rc += _client->write((char)pgm_read_byte_near(payload + i));
+   }
+   
+   lastOutActivity = millis();
+   return rc == len + 1 + plength;
+}
+
+boolean PubSubClient::write(uint8_t header, uint8_t* buf, uint16_t length) {
+   uint8_t lenBuf[4];
+   uint8_t llen = 0;
+   uint8_t digit;
+   uint8_t pos = 0;
+   uint8_t rc;
+   uint16_t len = length;
+   do {
+      digit = len % 128;
+      len = len / 128;
+      if (len > 0) {
+         digit |= 0x80;
+      }
+      lenBuf[pos++] = digit;
+      llen++;
+   } while(len>0);
+
+   buf[4-llen] = header;
+   for (int i=0;i<llen;i++) {
+      buf[5-llen+i] = lenBuf[i];
+   }
+
+//   Serial.print("write len: "); Serial.println(length+1+llen);
+//   size_t olen = length + 1 + llen;
+//   rc = _client->write(buf+(4-llen),length+1+llen);
+
+   const size_t SEND_AT_ONCE = 64;
+   size_t remains = length + 1 + llen;
+   // Serial.print("write len: "); Serial.println(remains);
+   const uint8_t *writebuf = buf + (4 - llen);
+   bool result = true;
+   while ((remains > 0) && result) {
+     size_t actuallySendChars = (remains > SEND_AT_ONCE) ? SEND_AT_ONCE : remains;
+     // Serial.print("tbs: "); Serial.println(actuallySendChars);
+     size_t sentChars = _client->write(writebuf, actuallySendChars);
+     result = sentChars == actuallySendChars;
+     remains -= sentChars;
+     writebuf += sentChars;
+   }
+
+   
+   lastOutActivity = millis();
+//   return (rc == 1+llen+length);
+   return result;
+}
+
+
+boolean PubSubClient::subscribe(char* topic) {
+   if (connected()) {
+      // Leave room in the buffer for header and variable length field
+      uint16_t length = 7;
+      nextMsgId++;
+      if (nextMsgId == 0) {
+         nextMsgId = 1;
+      }
+      buffer[0] = (nextMsgId >> 8);
+      buffer[1] = (nextMsgId & 0xFF);
+      length = writeString(topic, buffer,length);
+      buffer[length++] = 0; // Only do QoS 0 subs
+      return write(MQTTSUBSCRIBE|MQTTQOS1,buffer,length-5);
+   }
+   return false;
+}
+
+void PubSubClient::disconnect() {
+   buffer[0] = MQTTDISCONNECT;
+   buffer[1] = 0;
+   _client->write(buffer,2);
+   _client->stop();
+   lastInActivity = lastOutActivity = millis();
+}
+
+uint16_t PubSubClient::writeString(char* string, uint8_t* buf, uint16_t pos) {
+   char* idp = string;
+   uint16_t i = 0;
+   pos += 2;
+   while (*idp) {
+      buf[pos++] = *idp++;
+      i++;
+   }
+   buf[pos-i-2] = (i >> 8);
+   buf[pos-i-1] = (i & 0xFF);
+   return pos;
+}
+
+
+boolean PubSubClient::connected() {
+   int rc = (int)_client->connected();
+   //Serial.print("rc: "); Serial.println(rc);
+   if (!rc) {
+     //Serial.println("would stop");
+     _client->stop();
+     // while (true);
+   }
+   return rc;
+}
+

MQTT/PubSubClient.h

@@ -0,0 +1,75 @@
+/*
+ PubSubClient.h - A simple client for MQTT.
+  Nicholas O'Leary
+  http://knolleary.net
+*/
+
+#ifndef PubSubClient_h
+#define PubSubClient_h
+
+#include <Arduino.h>
+#include "Client.h"
+
+// MQTT_MAX_PACKET_SIZE : Maximum packet size
+#define MQTT_MAX_PACKET_SIZE 1024
+
+// MQTT_KEEPALIVE : keepAlive interval in Seconds
+#define MQTT_KEEPALIVE 15
+
+#define MQTTPROTOCOLVERSION 3
+#define MQTTCONNECT     1 << 4  // Client request to connect to Server
+#define MQTTCONNACK     2 << 4  // Connect Acknowledgment
+#define MQTTPUBLISH     3 << 4  // Publish message
+#define MQTTPUBACK      4 << 4  // Publish Acknowledgment
+#define MQTTPUBREC      5 << 4  // Publish Received (assured delivery part 1)
+#define MQTTPUBREL      6 << 4  // Publish Release (assured delivery part 2)
+#define MQTTPUBCOMP     7 << 4  // Publish Complete (assured delivery part 3)
+#define MQTTSUBSCRIBE   8 << 4  // Client Subscribe request
+#define MQTTSUBACK      9 << 4  // Subscribe Acknowledgment
+#define MQTTUNSUBSCRIBE 10 << 4 // Client Unsubscribe request
+#define MQTTUNSUBACK    11 << 4 // Unsubscribe Acknowledgment
+#define MQTTPINGREQ     12 << 4 // PING Request
+#define MQTTPINGRESP    13 << 4 // PING Response
+#define MQTTDISCONNECT  14 << 4 // Client is Disconnecting
+#define MQTTReserved    15 << 4 // Reserved
+
+#define MQTTQOS0        (0 << 1)
+#define MQTTQOS1        (1 << 1)
+#define MQTTQOS2        (2 << 1)
+
+class PubSubClient {
+private:
+   Client* _client;
+   uint8_t buffer[MQTT_MAX_PACKET_SIZE];
+   uint16_t nextMsgId;
+   unsigned long lastOutActivity;
+   unsigned long lastInActivity;
+   bool pingOutstanding;
+   void (*callback)(char*,uint8_t*,unsigned int);
+   uint16_t readPacket();
+   uint8_t readByte();
+   boolean write(uint8_t header, uint8_t* buf, uint16_t length);
+   uint16_t writeString(char* string, uint8_t* buf, uint16_t pos);
+   uint8_t *ip;
+   char* domain;
+   uint16_t port;
+public:
+   PubSubClient(Client& client);
+   PubSubClient(uint8_t *, uint16_t, void(*)(char*,uint8_t*,unsigned int),Client& client);
+   PubSubClient(char*, uint16_t, void(*)(char*,uint8_t*,unsigned int),Client& client);
+   boolean connect(char *);
+   boolean connect(char *, char *, char *);
+   boolean connect(char *, char *, uint8_t, uint8_t, char *);
+   boolean connect(char *, char *, char *, char *, uint8_t, uint8_t, char*);
+   void disconnect();
+   boolean publish(char *, char *);
+   boolean publish(char *, uint8_t *, unsigned int);
+   boolean publish(char *, uint8_t *, unsigned int, boolean);
+   boolean publish_P(char *, uint8_t PROGMEM *, unsigned int, boolean);
+   boolean subscribe(char *);
+   boolean loop();
+   boolean connected();
+};
+
+
+#endif

Metro/Metro.cpp

@@ -0,0 +1,73 @@
+
+#if defined(ARDUINO) && ARDUINO >= 100
+#include "Arduino.h"
+#else
+#include "WProgram.h"
+#endif
+#include "Metro.h"
+
+
+Metro::Metro(unsigned long interval_millis)
+{
+	this->autoreset = 0;
+	interval(interval_millis);
+	reset();
+}
+
+// New creator so I can use either the original check behavior or benjamin.soelberg's
+// suggested one (see below). 
+// autoreset = 0 is benjamin.soelberg's check behavior
+// autoreset != 0 is the original behavior
+
+Metro::Metro(unsigned long interval_millis, uint8_t autoreset)
+{   
+	this->autoreset = autoreset; // Fix by Paul Bouchier
+	interval(interval_millis);
+	reset();
+}
+
+void Metro::interval(unsigned long interval_millis)
+{
+  this->interval_millis = interval_millis;
+}
+
+// Benjamin.soelberg's check behavior:
+// When a check is true, add the interval to the internal counter.
+// This should guarantee a better overall stability.
+
+// Original check behavior:
+// When a check is true, add the interval to the current millis() counter.
+// This method can add a certain offset over time.
+
+char Metro::check()
+{
+  if (millis() - this->previous_millis >= this->interval_millis) {
+    // As suggested by benjamin.soelberg@gmail.com, the following line 
+    // this->previous_millis = millis();
+    // was changed to
+    // this->previous_millis += this->interval_millis;
+    
+    // If the interval is set to 0 we revert to the original behavior
+    if (this->interval_millis <= 0 || this->autoreset ) {
+    	this->previous_millis = millis();
+	} else {
+		this->previous_millis += this->interval_millis; 
+	}
+    
+    return 1;
+  }
+  
+  
+  
+  return 0;
+
+}
+
+void Metro::reset() 
+{
+ 
+  this->previous_millis = millis();
+
+}
+
+

Metro/Metro.h

@@ -0,0 +1,26 @@
+
+
+#ifndef Metro_h
+#define Metro_h
+
+#include <inttypes.h>
+
+class Metro
+{
+
+public:
+  Metro(unsigned long interval_millis);
+  Metro(unsigned long interval_millis, uint8_t autoreset);
+  void interval(unsigned long interval_millis);
+  char check();
+  void reset();
+	
+private:
+  uint8_t autoreset;
+  unsigned long  previous_millis, interval_millis;
+
+};
+
+#endif
+
+

PString/PString.cpp

@@ -0,0 +1,60 @@
+/*
+  PString.cpp - Lightweight printable string class
+  Copyright (c) 2009-2012 Mikal Hart.  All right reserved.
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#include "PString.h"
+
+void PString::begin()
+{
+  _cur = _buf;
+  if (_size > 0)
+    _buf[0] = '\0';
+}
+
+#if defined(ARDUINO) && ARDUINO >= 100
+size_t PString::write(uint8_t b)
+#else
+void PString::write(uint8_t b)
+#endif
+{
+  if (_cur + 1 < _buf + _size)
+  {
+    *_cur++ = (char)b;
+    *_cur = '\0';
+#if defined(ARDUINO) && ARDUINO >= 100
+		return 1;
+#endif
+	}
+
+#if defined(ARDUINO) && ARDUINO >= 100
+	return 0;
+#endif
+}
+
+int PString::format(char *str, ...) 
+{ 
+  va_list argptr;  
+  va_start(argptr, str); 
+  int ret = vsnprintf(_cur, _size - (_cur - _buf), str, argptr);
+  if (_size)
+     while (*_cur) 
+        ++_cur;
+  return ret;
+}
+
+

PString/PString.h

@@ -0,0 +1,87 @@
+/*
+  PString.h - Lightweight printable string class
+  Copyright (c) 2009-2012 Mikal Hart.  All right reserved.
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#ifndef PString_h
+#define PString_h
+
+#include "Print.h"
+#include <stdarg.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+
+#define PSTRING_LIBRARY_VERSION 3
+
+class PString : public Print
+{
+private:
+  char *_buf, *_cur;
+  size_t _size;
+public:
+#if defined(ARDUINO) && ARDUINO >= 100
+	virtual size_t write(uint8_t);
+#else
+	virtual void write(uint8_t);
+#endif
+
+public:
+
+  // Basic constructor requires a preallocated buffer
+  PString(char *buf, size_t size) : _buf(buf), _size(size)
+  { begin(); }
+
+  // templated constructors allow inline renderings of this type: PString(buf, size, myfloat[, modifier]);
+  template<class T> PString(char *buf, size_t size, T arg) : _buf(buf), _size(size) 
+  { begin(); print(arg); }
+  
+  template<class T> PString(char *buf, size_t size, T arg, int modifier) : _buf(buf), _size(size) 
+  { begin(); print(arg, modifier); }
+
+  // returns the length of the current string, not counting the 0 terminator
+  inline const size_t length() 
+  { return _cur - _buf; }
+
+  // returns the capacity of the string
+  inline const size_t capacity() 
+  { return _size; }
+
+  // gives access to the internal string
+  inline operator const char *() 
+  { return _buf; }
+
+  // compare to another string
+  bool operator==(const char *str) 
+  { return _size > 0 && !strcmp(_buf, str); }
+
+  // call this to re-use an existing string
+  void begin();
+
+  // This function allows assignment to an arbitrary scalar value like str = myfloat;
+  template<class T> inline PString &operator =(T arg) 
+  { begin(); print(arg); return *this; }
+
+  // Concatenation str += myfloat;
+  template<class T> inline PString &operator +=(T arg) 
+  { print(arg); return *this; }
+
+  // Safe access to sprintf-like formatting, e.g. str.format("Hi, my name is %s and I'm %d years old", name, age);
+  int format(char *str, ...);
+};
+
+#endif

RelayBox.cpp

@@ -1,15 +1,113 @@
 #include "RelayBox.h"
 #include "hardware.h"
 #include <avr/wdt.h>
+#include <SPI.h>
+#include <Ethernet.h>
+#include <Metro.h>
+#include <Streaming.h>
+#include <PubSubClient.h>
+#include <PString.h>
 
 
 
 
 
+uint8_t mac[]     = { 0x90, 0xA2, 0xDA, 0x00, 0x51, 0x07 };
+
+EthernetClient ethClient;
+
+void callback(char* topic, byte* payload, unsigned int length);
+
+// char server[] = "mqttbroker";
+char server[] = "192.168.75.1";
+PubSubClient client(server, 1883, callback, ethClient);
+uint8_t disconnectState = 0;
+uint32_t disconnectTime = 0;
+
+
+Metro minute = Metro(60000);
+Metro second = Metro(1000);
+uint32_t uptime;
+
+
+
+
 Switch switches[NUM_OF_LINES];
 
+
+void callback(char* topic, byte* payload, unsigned int length) {
+  const uint8_t BUFSIZE = 128;
+  if ((length + 1) >= BUFSIZE) {  // 1 for terminating NUL
+    Serial << "Received message too long, ignore it" << endl;
+  } else {
+    char buffer[BUFSIZE];
+    memcpy(buffer, payload, length);
+    *(buffer + length) = 0;
+    Serial << "Received message: " << length << ", " << String(topic) << ", " << String(buffer) << endl;
+
+    char *paramPtr = buffer;
+    char *commandStr = 0;
+    char *indexStr = 0;
+    char *stateStr = 0;
+    if ((paramPtr != 0) && (*paramPtr != 0)){
+      // command
+      commandStr = strsep(&paramPtr, " ");
+    }
+    if ((paramPtr != 0) && (*paramPtr != 0)){
+      indexStr = strsep(&paramPtr, " ");
+    }
+    if ((paramPtr != 0) && (*paramPtr != 0)){
+      stateStr = strsep(&paramPtr, " ");
+    }
+
+    if ((commandStr != 0) && (*commandStr != 0) &&
+        (indexStr != 0) && (*indexStr != 0) &&
+        (stateStr != 0) && (*stateStr != 0)) {
+      String command = String(commandStr);
+      int index = atoi(indexStr);
+      String state = String(stateStr);
+      bool validCommand = command.equals("switch");
+      bool validIndex = ! ((index < 0) || (index >= NUM_OF_LINES));
+
+      if (validCommand && validIndex) {
+        if (state.equalsIgnoreCase("on")) {
+          switches[index].on();
+        } else if (state.equalsIgnoreCase("off")) {
+          switches[index].off();
+        } else if (state.equalsIgnoreCase("toggle")) {
+          switches[index].toggle();
+        } else {
+          Serial << "Invalid state " << state << endl;
+        }
+      } else {
+        if (! validCommand) {
+          Serial << "Invalid command " << commandStr << endl;
+        }
+        if (! validIndex) {
+          Serial << "Invalid index " << indexStr << endl;
+        }
+      }
+    }
+  }
+}
+
+
+
+
 void setup() {
   Serial.begin(9600);
+
+  Serial << "Starting ... " << endl;
+
+  Ethernet.begin(mac);
+  Serial << "Got IP address: " << Ethernet.localIP() << endl;
+
+  disconnectState = 3;
+  disconnectTime = millis();
+
+  uptime = 0;
+
+
   for (uint8_t i = 0; i < NUM_OF_LINES; i++) {
     switches[i].begin(FEEDBACK_PIN[i], BUTTON_PIN[i], RELAY_PIN[i], LED_PIN[i]);
   }
@@ -24,38 +122,116 @@ void loop() {
   for (uint8_t i = 0; i < NUM_OF_LINES; i++) {
     switches[i].exec();
   }
-#else
-  for (uint8_t i = 0; i < NUM_OF_LINES; i++) {
-    digitalWrite(RELAY_PIN[i], false);
-    digitalWrite(LED_PIN[i], false);
-  }
-  delay(500);
-  for (uint8_t i = 0; i < NUM_OF_LINES; i++) {
-    digitalWrite(RELAY_PIN[i], true);
-    delay(100);
-  }
-  delay(500);
-  for (uint8_t i = 0; i < NUM_OF_LINES; i++) {
-    digitalWrite(RELAY_PIN[i], false);
-    delay(100);
-  }
-  delay(500);
-  for (uint8_t i = 0; i < NUM_OF_LINES; i++) {
-    digitalWrite(LED_PIN[i], true);
-    delay(100);
-  }
-  delay(500);
-  for (uint8_t i = 0; i < NUM_OF_LINES; i++) {
-    digitalWrite(LED_PIN[i], false);
-    delay(100);
-  }
-  delay(100);
 
-  while (true) {
+  if (minute.check() == 1) {
-    for (uint8_t i = 0; i < NUM_OF_LINES; i++) {
+    byte r = Ethernet.maintain();
-      digitalWrite(LED_PIN[i], digitalRead(FEEDBACK_PIN[i]));
+    Serial << "Ethernet.maintain: " << r << endl;
-      digitalWrite(RELAY_PIN[i], digitalRead(BUTTON_PIN[i]));
+    if ((r == DHCP_CHECK_REBIND_FAIL) || (r == DHCP_CHECK_RENEW_FAIL)) {
     }
   }
+
+  if ((disconnectState == 0) && (! client.loop())) {
+    disconnectState = 1;
+  }
+
+  switch (disconnectState) {
+  case 0:
+    // Serial.println("discState 0");
+    // everything fine
+    break;
+  case 1:
+    Serial.println("discState 1");
+    client.disconnect();
+    disconnectTime = millis();
+    disconnectState = 2;
+    break;
+  case 2:
+    Serial.println("discState 3");
+    if (disconnectTime + 2000 < millis()) {
+      disconnectState = 3;
+    }
+    break;
+  case 3:
+    Serial.println("discState 3");
+    if (client.connect("RelayBox")) {
+      client.subscribe("IoT/Command/RelayBox");
+      disconnectTime = millis();
+      disconnectState = 0;
+    } else {
+      disconnectState = 1;
+    }
+    break;
+  default:
+    disconnectState = 0;
+    break;
+  }
+
+
+
+  if (second.check() == 1) {
+    uptime++;
+
+    Serial.println("tick");
+
+    if (disconnectState == 0) {
+      String msg = String("{ \"metadata\": { \"device\": \"RelayBox\" }, \"data\": { \"uptime\": ") + uptime  + String("}}");
+      client.publish("IoT/Heartbeat/RelayBox", (char*)msg.c_str());
+
+      char strbuf[768];
+      memset(strbuf, sizeof(strbuf), 0);
+      PString buf = PString(strbuf, sizeof(strbuf));
+      buf << "{ \"metadata\": { \"device\": \"RelayBox\" }, " <<
+          "\"data\": {" <<
+          "\"switchStates\": [";
+      for (uint8_t i = 0; i < NUM_OF_LINES; i++) {
+        if (i != 0) {
+          buf << ", ";
+        }
+        buf << "{ \"index\": " << i << ", " <<
+            "\"state\": " << switches[i].getState() << ", " <<
+            "\"feedbackState\": " << switches[i].getFeedback() << ", " <<
+            "\"stateConflict\": " << switches[i].getStateConflict() << " }";
+      }
+      buf << "], " <<
+          "\"uptime\": " << uptime <<
+          "}" <<
+          "}" << endl;
+      //Serial << strbuf << endl;
+      client.publish("IoT/Status/RelayBox", strbuf);
+    }
+  }
+#else
+for (uint8_t i = 0; i < NUM_OF_LINES; i++) {
+  digitalWrite(RELAY_PIN[i], false);
+  digitalWrite(LED_PIN[i], false);
+}
+delay(500);
+for (uint8_t i = 0; i < NUM_OF_LINES; i++) {
+  digitalWrite(RELAY_PIN[i], true);
+  delay(100);
+}
+delay(500);
+for (uint8_t i = 0; i < NUM_OF_LINES; i++) {
+  digitalWrite(RELAY_PIN[i], false);
+  delay(100);
+}
+delay(500);
+for (uint8_t i = 0; i < NUM_OF_LINES; i++) {
+  digitalWrite(LED_PIN[i], true);
+  delay(100);
+}
+delay(500);
+for (uint8_t i = 0; i < NUM_OF_LINES; i++) {
+  digitalWrite(LED_PIN[i], false);
+  delay(100);
+}
+delay(100);
+
+while (true) {
+  for (uint8_t i = 0; i < NUM_OF_LINES; i++) {
+    digitalWrite(LED_PIN[i], digitalRead(FEEDBACK_PIN[i]));
+    digitalWrite(RELAY_PIN[i], digitalRead(BUTTON_PIN[i]));
+  }
+}
 #endif
 }

SPI/SPI.cpp

@@ -0,0 +1,193 @@
+/*
+ * Copyright (c) 2010 by Cristian Maglie <c.maglie@arduino.cc>
+ * Copyright (c) 2014 by Paul Stoffregen <paul@pjrc.com> (Transaction API)
+ * Copyright (c) 2014 by Matthijs Kooijman <matthijs@stdin.nl> (SPISettings AVR)
+ * Copyright (c) 2014 by Andrew J. Kroll <xxxajk@gmail.com> (atomicity fixes)
+ * SPI Master library for arduino.
+ *
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of either the GNU General Public License version 2
+ * or the GNU Lesser General Public License version 2.1, both as
+ * published by the Free Software Foundation.
+ */
+
+#include "SPI.h"
+
+SPIClass SPI;
+
+uint8_t SPIClass::initialized = 0;
+uint8_t SPIClass::interruptMode = 0;
+uint8_t SPIClass::interruptMask = 0;
+uint8_t SPIClass::interruptSave = 0;
+#ifdef SPI_TRANSACTION_MISMATCH_LED
+uint8_t SPIClass::inTransactionFlag = 0;
+#endif
+
+void SPIClass::begin()
+{
+  uint8_t sreg = SREG;
+  noInterrupts(); // Protect from a scheduler and prevent transactionBegin
+  if (!initialized) {
+    // Set SS to high so a connected chip will be "deselected" by default
+    digitalWrite(SS, HIGH);
+
+    // When the SS pin is set as OUTPUT, it can be used as
+    // a general purpose output port (it doesn't influence
+    // SPI operations).
+    pinMode(SS, OUTPUT);
+
+    // Warning: if the SS pin ever becomes a LOW INPUT then SPI
+    // automatically switches to Slave, so the data direction of
+    // the SS pin MUST be kept as OUTPUT.
+    SPCR |= _BV(MSTR);
+    SPCR |= _BV(SPE);
+
+    // Set direction register for SCK and MOSI pin.
+    // MISO pin automatically overrides to INPUT.
+    // By doing this AFTER enabling SPI, we avoid accidentally
+    // clocking in a single bit since the lines go directly
+    // from "input" to SPI control.
+    // http://code.google.com/p/arduino/issues/detail?id=888
+    pinMode(SCK, OUTPUT);
+    pinMode(MOSI, OUTPUT);
+  }
+  initialized++; // reference count
+  SREG = sreg;
+}
+
+void SPIClass::end() {
+  uint8_t sreg = SREG;
+  noInterrupts(); // Protect from a scheduler and prevent transactionBegin
+  // Decrease the reference counter
+  if (initialized)
+    initialized--;
+  // If there are no more references disable SPI
+  if (!initialized) {
+    SPCR &= ~_BV(SPE);
+    interruptMode = 0;
+    #ifdef SPI_TRANSACTION_MISMATCH_LED
+    inTransactionFlag = 0;
+    #endif
+  }
+  SREG = sreg;
+}
+
+// mapping of interrupt numbers to bits within SPI_AVR_EIMSK
+#if defined(__AVR_ATmega32U4__)
+  #define SPI_INT0_MASK  (1<<INT0)
+  #define SPI_INT1_MASK  (1<<INT1)
+  #define SPI_INT2_MASK  (1<<INT2)
+  #define SPI_INT3_MASK  (1<<INT3)
+  #define SPI_INT4_MASK  (1<<INT6)
+#elif defined(__AVR_AT90USB646__) || defined(__AVR_AT90USB1286__)
+  #define SPI_INT0_MASK  (1<<INT0)
+  #define SPI_INT1_MASK  (1<<INT1)
+  #define SPI_INT2_MASK  (1<<INT2)
+  #define SPI_INT3_MASK  (1<<INT3)
+  #define SPI_INT4_MASK  (1<<INT4)
+  #define SPI_INT5_MASK  (1<<INT5)
+  #define SPI_INT6_MASK  (1<<INT6)
+  #define SPI_INT7_MASK  (1<<INT7)
+#elif defined(EICRA) && defined(EICRB) && defined(EIMSK)
+  #define SPI_INT0_MASK  (1<<INT4)
+  #define SPI_INT1_MASK  (1<<INT5)
+  #define SPI_INT2_MASK  (1<<INT0)
+  #define SPI_INT3_MASK  (1<<INT1)
+  #define SPI_INT4_MASK  (1<<INT2)
+  #define SPI_INT5_MASK  (1<<INT3)
+  #define SPI_INT6_MASK  (1<<INT6)
+  #define SPI_INT7_MASK  (1<<INT7)
+#else
+  #ifdef INT0
+  #define SPI_INT0_MASK  (1<<INT0)
+  #endif
+  #ifdef INT1
+  #define SPI_INT1_MASK  (1<<INT1)
+  #endif
+  #ifdef INT2
+  #define SPI_INT2_MASK  (1<<INT2)
+  #endif
+#endif
+
+void SPIClass::usingInterrupt(uint8_t interruptNumber)
+{
+  uint8_t mask = 0;
+  uint8_t sreg = SREG;
+  noInterrupts(); // Protect from a scheduler and prevent transactionBegin
+  switch (interruptNumber) {
+  #ifdef SPI_INT0_MASK
+  case 0: mask = SPI_INT0_MASK; break;
+  #endif
+  #ifdef SPI_INT1_MASK
+  case 1: mask = SPI_INT1_MASK; break;
+  #endif
+  #ifdef SPI_INT2_MASK
+  case 2: mask = SPI_INT2_MASK; break;
+  #endif
+  #ifdef SPI_INT3_MASK
+  case 3: mask = SPI_INT3_MASK; break;
+  #endif
+  #ifdef SPI_INT4_MASK
+  case 4: mask = SPI_INT4_MASK; break;
+  #endif
+  #ifdef SPI_INT5_MASK
+  case 5: mask = SPI_INT5_MASK; break;
+  #endif
+  #ifdef SPI_INT6_MASK
+  case 6: mask = SPI_INT6_MASK; break;
+  #endif
+  #ifdef SPI_INT7_MASK
+  case 7: mask = SPI_INT7_MASK; break;
+  #endif
+  default:
+    interruptMode = 2;
+    break;
+  }
+  interruptMask |= mask;
+  if (!interruptMode)
+    interruptMode = 1;
+  SREG = sreg;
+}
+
+void SPIClass::notUsingInterrupt(uint8_t interruptNumber)
+{
+  // Once in mode 2 we can't go back to 0 without a proper reference count
+  if (interruptMode == 2)
+    return;
+  uint8_t mask = 0;
+  uint8_t sreg = SREG;
+  noInterrupts(); // Protect from a scheduler and prevent transactionBegin
+  switch (interruptNumber) {
+  #ifdef SPI_INT0_MASK
+  case 0: mask = SPI_INT0_MASK; break;
+  #endif
+  #ifdef SPI_INT1_MASK
+  case 1: mask = SPI_INT1_MASK; break;
+  #endif
+  #ifdef SPI_INT2_MASK
+  case 2: mask = SPI_INT2_MASK; break;
+  #endif
+  #ifdef SPI_INT3_MASK
+  case 3: mask = SPI_INT3_MASK; break;
+  #endif
+  #ifdef SPI_INT4_MASK
+  case 4: mask = SPI_INT4_MASK; break;
+  #endif
+  #ifdef SPI_INT5_MASK
+  case 5: mask = SPI_INT5_MASK; break;
+  #endif
+  #ifdef SPI_INT6_MASK
+  case 6: mask = SPI_INT6_MASK; break;
+  #endif
+  #ifdef SPI_INT7_MASK
+  case 7: mask = SPI_INT7_MASK; break;
+  #endif
+  default:
+    break;
+    // this case can't be reached
+  }
+  interruptMask &= ~mask;
+  if (!interruptMask)
+    interruptMode = 0;
+  SREG = sreg;
+}

SPI/SPI.h

@@ -0,0 +1,324 @@
+/*
+ * Copyright (c) 2010 by Cristian Maglie <c.maglie@arduino.cc>
+ * Copyright (c) 2014 by Paul Stoffregen <paul@pjrc.com> (Transaction API)
+ * Copyright (c) 2014 by Matthijs Kooijman <matthijs@stdin.nl> (SPISettings AVR)
+ * Copyright (c) 2014 by Andrew J. Kroll <xxxajk@gmail.com> (atomicity fixes)
+ * SPI Master library for arduino.
+ *
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of either the GNU General Public License version 2
+ * or the GNU Lesser General Public License version 2.1, both as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef _SPI_H_INCLUDED
+#define _SPI_H_INCLUDED
+
+#include <Arduino.h>
+
+// SPI_HAS_TRANSACTION means SPI has beginTransaction(), endTransaction(),
+// usingInterrupt(), and SPISetting(clock, bitOrder, dataMode)
+#define SPI_HAS_TRANSACTION 1
+
+// SPI_HAS_NOTUSINGINTERRUPT means that SPI has notUsingInterrupt() method
+#define SPI_HAS_NOTUSINGINTERRUPT 1
+
+// SPI_ATOMIC_VERSION means that SPI has atomicity fixes and what version.
+// This way when there is a bug fix you can check this define to alert users
+// of your code if it uses better version of this library.
+// This also implies everything that SPI_HAS_TRANSACTION as documented above is
+// available too.
+#define SPI_ATOMIC_VERSION 1
+
+// Uncomment this line to add detection of mismatched begin/end transactions.
+// A mismatch occurs if other libraries fail to use SPI.endTransaction() for
+// each SPI.beginTransaction().  Connect an LED to this pin.  The LED will turn
+// on if any mismatch is ever detected.
+//#define SPI_TRANSACTION_MISMATCH_LED 5
+
+#ifndef LSBFIRST
+#define LSBFIRST 0
+#endif
+#ifndef MSBFIRST
+#define MSBFIRST 1
+#endif
+
+#define SPI_CLOCK_DIV4 0x00
+#define SPI_CLOCK_DIV16 0x01
+#define SPI_CLOCK_DIV64 0x02
+#define SPI_CLOCK_DIV128 0x03
+#define SPI_CLOCK_DIV2 0x04
+#define SPI_CLOCK_DIV8 0x05
+#define SPI_CLOCK_DIV32 0x06
+
+#define SPI_MODE0 0x00
+#define SPI_MODE1 0x04
+#define SPI_MODE2 0x08
+#define SPI_MODE3 0x0C
+
+#define SPI_MODE_MASK 0x0C  // CPOL = bit 3, CPHA = bit 2 on SPCR
+#define SPI_CLOCK_MASK 0x03  // SPR1 = bit 1, SPR0 = bit 0 on SPCR
+#define SPI_2XCLOCK_MASK 0x01  // SPI2X = bit 0 on SPSR
+
+// define SPI_AVR_EIMSK for AVR boards with external interrupt pins
+#if defined(EIMSK)
+  #define SPI_AVR_EIMSK  EIMSK
+#elif defined(GICR)
+  #define SPI_AVR_EIMSK  GICR
+#elif defined(GIMSK)
+  #define SPI_AVR_EIMSK  GIMSK
+#endif
+
+class SPISettings {
+public:
+  SPISettings(uint32_t clock, uint8_t bitOrder, uint8_t dataMode) {
+    if (__builtin_constant_p(clock)) {
+      init_AlwaysInline(clock, bitOrder, dataMode);
+    } else {
+      init_MightInline(clock, bitOrder, dataMode);
+    }
+  }
+  SPISettings() {
+    init_AlwaysInline(4000000, MSBFIRST, SPI_MODE0);
+  }
+private:
+  void init_MightInline(uint32_t clock, uint8_t bitOrder, uint8_t dataMode) {
+    init_AlwaysInline(clock, bitOrder, dataMode);
+  }
+  void init_AlwaysInline(uint32_t clock, uint8_t bitOrder, uint8_t dataMode)
+    __attribute__((__always_inline__)) {
+    // Clock settings are defined as follows. Note that this shows SPI2X
+    // inverted, so the bits form increasing numbers. Also note that
+    // fosc/64 appears twice
+    // SPR1 SPR0 ~SPI2X Freq
+    //   0    0     0   fosc/2
+    //   0    0     1   fosc/4
+    //   0    1     0   fosc/8
+    //   0    1     1   fosc/16
+    //   1    0     0   fosc/32
+    //   1    0     1   fosc/64
+    //   1    1     0   fosc/64
+    //   1    1     1   fosc/128
+
+    // We find the fastest clock that is less than or equal to the
+    // given clock rate. The clock divider that results in clock_setting
+    // is 2 ^^ (clock_div + 1). If nothing is slow enough, we'll use the
+    // slowest (128 == 2 ^^ 7, so clock_div = 6).
+    uint8_t clockDiv;
+
+    // When the clock is known at compiletime, use this if-then-else
+    // cascade, which the compiler knows how to completely optimize
+    // away. When clock is not known, use a loop instead, which generates
+    // shorter code.
+    if (__builtin_constant_p(clock)) {
+      if (clock >= F_CPU / 2) {
+        clockDiv = 0;
+      } else if (clock >= F_CPU / 4) {
+        clockDiv = 1;
+      } else if (clock >= F_CPU / 8) {
+        clockDiv = 2;
+      } else if (clock >= F_CPU / 16) {
+        clockDiv = 3;
+      } else if (clock >= F_CPU / 32) {
+        clockDiv = 4;
+      } else if (clock >= F_CPU / 64) {
+        clockDiv = 5;
+      } else {
+        clockDiv = 6;
+      }
+    } else {
+      uint32_t clockSetting = F_CPU / 2;
+      clockDiv = 0;
+      while (clockDiv < 6 && clock < clockSetting) {
+        clockSetting /= 2;
+        clockDiv++;
+      }
+    }
+
+    // Compensate for the duplicate fosc/64
+    if (clockDiv == 6)
+    clockDiv = 7;
+
+    // Invert the SPI2X bit
+    clockDiv ^= 0x1;
+
+    // Pack into the SPISettings class
+    spcr = _BV(SPE) | _BV(MSTR) | ((bitOrder == LSBFIRST) ? _BV(DORD) : 0) |
+      (dataMode & SPI_MODE_MASK) | ((clockDiv >> 1) & SPI_CLOCK_MASK);
+    spsr = clockDiv & SPI_2XCLOCK_MASK;
+  }
+  uint8_t spcr;
+  uint8_t spsr;
+  friend class SPIClass;
+};
+
+
+class SPIClass {
+public:
+  // Initialize the SPI library
+  static void begin();
+
+  // If SPI is used from within an interrupt, this function registers
+  // that interrupt with the SPI library, so beginTransaction() can
+  // prevent conflicts.  The input interruptNumber is the number used
+  // with attachInterrupt.  If SPI is used from a different interrupt
+  // (eg, a timer), interruptNumber should be 255.
+  static void usingInterrupt(uint8_t interruptNumber);
+  // And this does the opposite.
+  static void notUsingInterrupt(uint8_t interruptNumber);
+  // Note: the usingInterrupt and notUsingInterrupt functions should
+  // not to be called from ISR context or inside a transaction.
+  // For details see:
+  // https://github.com/arduino/Arduino/pull/2381
+  // https://github.com/arduino/Arduino/pull/2449
+
+  // Before using SPI.transfer() or asserting chip select pins,
+  // this function is used to gain exclusive access to the SPI bus
+  // and configure the correct settings.
+  inline static void beginTransaction(SPISettings settings) {
+    if (interruptMode > 0) {
+      uint8_t sreg = SREG;
+      noInterrupts();
+
+      #ifdef SPI_AVR_EIMSK
+      if (interruptMode == 1) {
+        interruptSave = SPI_AVR_EIMSK;
+        SPI_AVR_EIMSK &= ~interruptMask;
+        SREG = sreg;
+      } else
+      #endif
+      {
+        interruptSave = sreg;
+      }
+    }
+
+    #ifdef SPI_TRANSACTION_MISMATCH_LED
+    if (inTransactionFlag) {
+      pinMode(SPI_TRANSACTION_MISMATCH_LED, OUTPUT);
+      digitalWrite(SPI_TRANSACTION_MISMATCH_LED, HIGH);
+    }
+    inTransactionFlag = 1;
+    #endif
+
+    SPCR = settings.spcr;
+    SPSR = settings.spsr;
+  }
+
+  // Write to the SPI bus (MOSI pin) and also receive (MISO pin)
+  inline static uint8_t transfer(uint8_t data) {
+    SPDR = data;
+    /*
+     * The following NOP introduces a small delay that can prevent the wait
+     * loop form iterating when running at the maximum speed. This gives
+     * about 10% more speed, even if it seems counter-intuitive. At lower
+     * speeds it is unnoticed.
+     */
+    asm volatile("nop");
+    while (!(SPSR & _BV(SPIF))) ; // wait
+    return SPDR;
+  }
+  inline static uint16_t transfer16(uint16_t data) {
+    union { uint16_t val; struct { uint8_t lsb; uint8_t msb; }; } in, out;
+    in.val = data;
+    if (!(SPCR & _BV(DORD))) {
+      SPDR = in.msb;
+      asm volatile("nop"); // See transfer(uint8_t) function
+      while (!(SPSR & _BV(SPIF))) ;
+      out.msb = SPDR;
+      SPDR = in.lsb;
+      asm volatile("nop");
+      while (!(SPSR & _BV(SPIF))) ;
+      out.lsb = SPDR;
+    } else {
+      SPDR = in.lsb;
+      asm volatile("nop");
+      while (!(SPSR & _BV(SPIF))) ;
+      out.lsb = SPDR;
+      SPDR = in.msb;
+      asm volatile("nop");
+      while (!(SPSR & _BV(SPIF))) ;
+      out.msb = SPDR;
+    }
+    return out.val;
+  }
+  inline static void transfer(void *buf, size_t count) {
+    if (count == 0) return;
+    uint8_t *p = (uint8_t *)buf;
+    SPDR = *p;
+    while (--count > 0) {
+      uint8_t out = *(p + 1);
+      while (!(SPSR & _BV(SPIF))) ;
+      uint8_t in = SPDR;
+      SPDR = out;
+      *p++ = in;
+    }
+    while (!(SPSR & _BV(SPIF))) ;
+    *p = SPDR;
+  }
+  // After performing a group of transfers and releasing the chip select
+  // signal, this function allows others to access the SPI bus
+  inline static void endTransaction(void) {
+    #ifdef SPI_TRANSACTION_MISMATCH_LED
+    if (!inTransactionFlag) {
+      pinMode(SPI_TRANSACTION_MISMATCH_LED, OUTPUT);
+      digitalWrite(SPI_TRANSACTION_MISMATCH_LED, HIGH);
+    }
+    inTransactionFlag = 0;
+    #endif
+
+    if (interruptMode > 0) {
+      #ifdef SPI_AVR_EIMSK
+      uint8_t sreg = SREG;
+      #endif
+      noInterrupts();
+      #ifdef SPI_AVR_EIMSK
+      if (interruptMode == 1) {
+        SPI_AVR_EIMSK = interruptSave;
+        SREG = sreg;
+      } else
+      #endif
+      {
+        SREG = interruptSave;
+      }
+    }
+  }
+
+  // Disable the SPI bus
+  static void end();
+
+  // This function is deprecated.  New applications should use
+  // beginTransaction() to configure SPI settings.
+  inline static void setBitOrder(uint8_t bitOrder) {
+    if (bitOrder == LSBFIRST) SPCR |= _BV(DORD);
+    else SPCR &= ~(_BV(DORD));
+  }
+  // This function is deprecated.  New applications should use
+  // beginTransaction() to configure SPI settings.
+  inline static void setDataMode(uint8_t dataMode) {
+    SPCR = (SPCR & ~SPI_MODE_MASK) | dataMode;
+  }
+  // This function is deprecated.  New applications should use
+  // beginTransaction() to configure SPI settings.
+  inline static void setClockDivider(uint8_t clockDiv) {
+    SPCR = (SPCR & ~SPI_CLOCK_MASK) | (clockDiv & SPI_CLOCK_MASK);
+    SPSR = (SPSR & ~SPI_2XCLOCK_MASK) | ((clockDiv >> 2) & SPI_2XCLOCK_MASK);
+  }
+  // These undocumented functions should not be used.  SPI.transfer()
+  // polls the hardware flag which is automatically cleared as the
+  // AVR responds to SPI's interrupt
+  inline static void attachInterrupt() { SPCR |= _BV(SPIE); }
+  inline static void detachInterrupt() { SPCR &= ~_BV(SPIE); }
+
+private:
+  static uint8_t initialized;
+  static uint8_t interruptMode; // 0=none, 1=mask, 2=global
+  static uint8_t interruptMask; // which interrupts to mask
+  static uint8_t interruptSave; // temp storage, to restore state
+  #ifdef SPI_TRANSACTION_MISMATCH_LED
+  static uint8_t inTransactionFlag;
+  #endif
+};
+
+extern SPIClass SPI;
+
+#endif