commit eb73818297bbfbe3bfe0b2870304404e577a4be3
Author: Wolfgang Hottgenroth <wolfgang.hottgenroth@icloud.com>
Date:   Sun Oct 9 11:38:51 2022 +0200

    initial

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..bd2b439
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+secrets.py
+
diff --git a/boot.py b/boot.py
new file mode 100644
index 0000000..b8e7bb0
--- /dev/null
+++ b/boot.py
@@ -0,0 +1 @@
+# boot.py -- run on boot-up
diff --git a/config.py b/config.py
new file mode 100644
index 0000000..433a5b4
--- /dev/null
+++ b/config.py
@@ -0,0 +1,5 @@
+ssid = 'telemetry'
+
+mqtt_server = '172.16.10.47'
+heartbeat_topic = b'IoT/rpipwThermometer/0/Heartbeat'
+watchdog_topic = b'IoT/Watchdog'
diff --git a/main.py b/main.py
new file mode 100644
index 0000000..36aadc9
--- /dev/null
+++ b/main.py
@@ -0,0 +1,77 @@
+# main.py -- put your code here!
+
+from umqttsimple import MQTTClient
+import time
+import ubinascii
+from machine import WDT
+import network
+import os
+import config
+import secrets
+
+last_message = 0
+message_interval = 5
+counter = 0
+ringFlag = False
+wdt = None
+wdtCnt = 0
+client = None
+
+def init():
+    wlan = network.WLAN(network.STA_IF)
+    wlan.active(True)
+    wlan.connect(config.ssid, secrets.wpakey)
+
+    while (not wlan.isconnected()):
+        print('Not yet connected to WLAN')
+
+    print('Connected to WLAN')
+
+    global client
+    clientId = ubinascii.hexlify(bytearray(os.urandom(16))).decode()
+    client = MQTTClient(clientId, config.mqtt_server, keepalive=60, ssl=True)
+    client.set_callback(mqtt_callback)
+    client.connect()
+    client.subscribe(config.watchdog_topic)
+    print(f"Connected to {config.mqtt_server} MQTT Broker")
+
+    global wdt
+    wdt = WDT(timeout=5000)
+    wdt.feed()
+    print("Watchdog enabled")
+
+
+def mqtt_callback(topic, msg):
+    global wdt, wdtCnt
+    print(f"Received: {topic}: {msg}")
+    if topic == config.watchdog_topic:
+        wdtCnt += 1
+        print(f"feed watchdog {wdtCnt}")
+        wdt.feed()
+
+def main():
+    global client
+    print("Hello")
+    time.sleep(1)
+
+    try:
+        init()
+    except Exception as e:
+        print(f"Some error when starting: {e}")
+        time.sleep(15)
+        machine.reset()
+
+    last_time = time.ticks_ms()
+    while True:
+        current_time = time.ticks_ms()
+
+        if (time.ticks_diff(current_time, last_time) > 250):
+            last_time = current_time
+            client.ping()
+            client.wait_msg()
+
+
+    client.disconnect()
+    
+if __name__ == "__main__":
+    main()
\ No newline at end of file
diff --git a/umqttsimple.py b/umqttsimple.py
new file mode 100644
index 0000000..28a61da
--- /dev/null
+++ b/umqttsimple.py
@@ -0,0 +1,215 @@
+import usocket as socket
+import ustruct as struct
+from ubinascii import hexlify
+
+
+class MQTTException(Exception):
+    pass
+
+
+class MQTTClient:
+    def __init__(
+        self,
+        client_id,
+        server,
+        port=0,
+        user=None,
+        password=None,
+        keepalive=0,
+        ssl=False,
+        ssl_params={},
+    ):
+        if port == 0:
+            port = 8883 if ssl else 1883
+        self.client_id = client_id
+        self.sock = None
+        self.server = server
+        self.port = port
+        self.ssl = ssl
+        self.ssl_params = ssl_params
+        self.pid = 0
+        self.cb = None
+        self.user = user
+        self.pswd = password
+        self.keepalive = keepalive
+        self.lw_topic = None
+        self.lw_msg = None
+        self.lw_qos = 0
+        self.lw_retain = False
+
+    def _send_str(self, s):
+        self.sock.write(struct.pack("!H", len(s)))
+        self.sock.write(s)
+
+    def _recv_len(self):
+        n = 0
+        sh = 0
+        while 1:
+            b = self.sock.read(1)[0]
+            n |= (b & 0x7F) << sh
+            if not b & 0x80:
+                return n
+            sh += 7
+
+    def set_callback(self, f):
+        self.cb = f
+
+    def set_last_will(self, topic, msg, retain=False, qos=0):
+        assert 0 <= qos <= 2
+        assert topic
+        self.lw_topic = topic
+        self.lw_msg = msg
+        self.lw_qos = qos
+        self.lw_retain = retain
+
+    def connect(self, clean_session=True):
+        self.sock = socket.socket()
+        addr = socket.getaddrinfo(self.server, self.port)[0][-1]
+        self.sock.connect(addr)
+        if self.ssl:
+            import ussl
+
+            self.sock = ussl.wrap_socket(self.sock, **self.ssl_params)
+        premsg = bytearray(b"\x10\0\0\0\0\0")
+        msg = bytearray(b"\x04MQTT\x04\x02\0\0")
+
+        sz = 10 + 2 + len(self.client_id)
+        msg[6] = clean_session << 1
+        if self.user is not None:
+            sz += 2 + len(self.user) + 2 + len(self.pswd)
+            msg[6] |= 0xC0
+        if self.keepalive:
+            assert self.keepalive < 65536
+            msg[7] |= self.keepalive >> 8
+            msg[8] |= self.keepalive & 0x00FF
+        if self.lw_topic:
+            sz += 2 + len(self.lw_topic) + 2 + len(self.lw_msg)
+            msg[6] |= 0x4 | (self.lw_qos & 0x1) << 3 | (self.lw_qos & 0x2) << 3
+            msg[6] |= self.lw_retain << 5
+
+        i = 1
+        while sz > 0x7F:
+            premsg[i] = (sz & 0x7F) | 0x80
+            sz >>= 7
+            i += 1
+        premsg[i] = sz
+
+        self.sock.write(premsg, i + 2)
+        self.sock.write(msg)
+        # print(hex(len(msg)), hexlify(msg, ":"))
+        self._send_str(self.client_id)
+        if self.lw_topic:
+            self._send_str(self.lw_topic)
+            self._send_str(self.lw_msg)
+        if self.user is not None:
+            self._send_str(self.user)
+            self._send_str(self.pswd)
+        resp = self.sock.read(4)
+        assert resp[0] == 0x20 and resp[1] == 0x02
+        if resp[3] != 0:
+            raise MQTTException(resp[3])
+        return resp[2] & 1
+
+    def disconnect(self):
+        self.sock.write(b"\xe0\0")
+        self.sock.close()
+
+    def ping(self):
+        self.sock.write(b"\xc0\0")
+
+    def publish(self, topic, msg, retain=False, qos=0):
+        pkt = bytearray(b"\x30\0\0\0")
+        pkt[0] |= qos << 1 | retain
+        sz = 2 + len(topic) + len(msg)
+        if qos > 0:
+            sz += 2
+        assert sz < 2097152
+        i = 1
+        while sz > 0x7F:
+            pkt[i] = (sz & 0x7F) | 0x80
+            sz >>= 7
+            i += 1
+        pkt[i] = sz
+        # print(hex(len(pkt)), hexlify(pkt, ":"))
+        self.sock.write(pkt, i + 1)
+        self._send_str(topic)
+        if qos > 0:
+            self.pid += 1
+            pid = self.pid
+            struct.pack_into("!H", pkt, 0, pid)
+            self.sock.write(pkt, 2)
+        self.sock.write(msg)
+        if qos == 1:
+            while 1:
+                op = self.wait_msg()
+                if op == 0x40:
+                    sz = self.sock.read(1)
+                    assert sz == b"\x02"
+                    rcv_pid = self.sock.read(2)
+                    rcv_pid = rcv_pid[0] << 8 | rcv_pid[1]
+                    if pid == rcv_pid:
+                        return
+        elif qos == 2:
+            assert 0
+
+    def subscribe(self, topic, qos=0):
+        assert self.cb is not None, "Subscribe callback is not set"
+        pkt = bytearray(b"\x82\0\0\0")
+        self.pid += 1
+        struct.pack_into("!BH", pkt, 1, 2 + 2 + len(topic) + 1, self.pid)
+        # print(hex(len(pkt)), hexlify(pkt, ":"))
+        self.sock.write(pkt)
+        self._send_str(topic)
+        self.sock.write(qos.to_bytes(1, "little"))
+        while 1:
+            op = self.wait_msg()
+            if op == 0x90:
+                resp = self.sock.read(4)
+                # print(resp)
+                assert resp[1] == pkt[2] and resp[2] == pkt[3]
+                if resp[3] == 0x80:
+                    raise MQTTException(resp[3])
+                return
+
+    # Wait for a single incoming MQTT message and process it.
+    # Subscribed messages are delivered to a callback previously
+    # set by .set_callback() method. Other (internal) MQTT
+    # messages processed internally.
+    def wait_msg(self):
+        res = self.sock.read(1)
+        #self.sock.setblocking(True)
+        if res is None:
+            return None
+        if res == b"":
+            raise OSError(-1)
+        if res == b"\xd0":  # PINGRESP
+            sz = self.sock.read(1)[0]
+            assert sz == 0
+            return None
+        op = res[0]
+        if op & 0xF0 != 0x30:
+            return op
+        sz = self._recv_len()
+        topic_len = self.sock.read(2)
+        topic_len = (topic_len[0] << 8) | topic_len[1]
+        topic = self.sock.read(topic_len)
+        sz -= topic_len + 2
+        if op & 6:
+            pid = self.sock.read(2)
+            pid = pid[0] << 8 | pid[1]
+            sz -= 2
+        msg = self.sock.read(sz)
+        self.cb(topic, msg)
+        if op & 6 == 2:
+            pkt = bytearray(b"\x40\x02\0\0")
+            struct.pack_into("!H", pkt, 2, pid)
+            self.sock.write(pkt)
+        elif op & 6 == 4:
+            assert 0
+
+    # Checks whether a pending message from server is available.
+    # If not, returns immediately with None. Otherwise, does
+    # the same processing as wait_msg.
+    def check_msg(self):
+        self.sock.setblocking(False)
+        return self.wait_msg()
\ No newline at end of file
diff --git a/urequest.py b/urequest.py
new file mode 100644
index 0000000..5478aad
--- /dev/null
+++ b/urequest.py
@@ -0,0 +1,120 @@
+import usocket
+import ujson
+try:
+    import ussl
+    SUPPORT_SSL = True
+except ImportError:
+    ussl = None
+    SUPPORT_SSL = False
+
+SUPPORT_TIMEOUT = hasattr(usocket.socket, 'settimeout')
+CONTENT_TYPE_JSON = 'application/json'
+
+
+class Response(object):
+    def __init__(self, status_code, raw):
+        self.status_code = status_code
+        self.raw = raw
+        self._content = False
+        self.encoding = 'utf-8'
+
+    @property
+    def content(self):
+        if self._content is False:
+            self._content = self.raw.read()
+            self.raw.close()
+            self.raw = None
+
+        return self._content
+
+    @property
+    def text(self):
+        content = self.content
+
+        return str(content, self.encoding) if content else ''
+
+    def close(self):
+        if self.raw is not None:
+            self._content = None
+            self.raw.close()
+            self.raw = None
+
+    def json(self):
+        return ujson.loads(self.text)
+
+    def raise_for_status(self):
+        if 400 <= self.status_code < 500:
+            raise OSError('Client error: %s' % self.status_code)
+        if 500 <= self.status_code < 600:
+            raise OSError('Server error: %s' % self.status_code)
+
+
+# Adapted from upip
+def request(method, url, json=None, timeout=None, headers=None):
+    urlparts = url.split('/', 3)
+    proto = urlparts[0]
+    host = urlparts[2]
+    urlpath = '' if len(urlparts) < 4 else urlparts[3]
+
+    if proto == 'http:':
+        port = 80
+    elif proto == 'https:':
+        port = 443
+    else:
+        raise OSError('Unsupported protocol: %s' % proto[:-1])
+
+    if ':' in host:
+        host, port = host.split(':')
+        port = int(port)
+
+    if json is not None:
+        content = ujson.dumps(json)
+        content_type = CONTENT_TYPE_JSON
+    else:
+        content = None
+
+    ai = usocket.getaddrinfo(host, port)
+    addr = ai[0][4]
+
+    sock = usocket.socket()
+
+    if timeout is not None:
+        assert SUPPORT_TIMEOUT, 'Socket does not support timeout'
+        sock.settimeout(timeout)
+
+    sock.connect(addr)
+
+    if proto == 'https:':
+        assert SUPPORT_SSL, 'HTTPS not supported: could not find ussl'
+        sock = ussl.wrap_socket(sock)
+
+    sock.write('%s /%s HTTP/1.0\r\nHost: %s\r\n' % (method, urlpath, host))
+
+    if headers is not None:
+        for header in headers.items():
+            sock.write('%s: %s\r\n' % header)
+
+    if content is not None:
+        sock.write('content-length: %s\r\n' % len(content))
+        sock.write('content-type: %s\r\n' % content_type)
+        sock.write('\r\n')
+        sock.write(content)
+    else:
+        sock.write('\r\n')
+
+    l = sock.readline()
+    protover, status, msg = l.split(None, 2)
+
+    # Skip headers
+    while sock.readline() != b'\r\n':
+        pass
+
+    return Response(int(status), sock)
+
+
+def get(url, **kwargs):
+    return request('GET', url, **kwargs)
+
+
+def post(url, **kwargs):
+    return request('POST', url, **kwargs)
\ No newline at end of file