From ecfc55705ac91cd80f22ed12f545da667ddcf44f Mon Sep 17 00:00:00 2001 From: Wolfgang Hottgenroth Date: Tue, 22 May 2018 15:13:47 +0200 Subject: [PATCH] prepare another post --- docroot/posts/2018-01-26.01/article.pag | 310 ++++++++++++++++++++++++ 1 file changed, 310 insertions(+) create mode 100644 docroot/posts/2018-01-26.01/article.pag diff --git a/docroot/posts/2018-01-26.01/article.pag b/docroot/posts/2018-01-26.01/article.pag new file mode 100644 index 0000000..6f57912 --- /dev/null +++ b/docroot/posts/2018-01-26.01/article.pag @@ -0,0 +1,310 @@ + +

+In my previous ESP8266 based weekend projects I always hardcoded configuration data. For the ESP8266 these are at least the WiFi credentials SSID and WPA key. Moving it into a different WiFi network requires re-flashing it. There must be a better way I thought and found that's a single line of code to run the ESP8266 as an accesspoint, which opens its own WiFi network. +

+ +

+So, I first hardcoded a web page with a form to enter configuration data, a data structure to hold it and some code to store it into the EEPROM or load it there. +It appears that this was an error-prone process with a lot of redudancy in the code. +

+ +

+For that reason I wrote an approach with a small template-based generator script: +

+ +

+

+
+#!/usr/bin/python
+
+from Cheetah.Template import Template
+
+configItems = [
+    { "label" : "_" ,  "key" : "magic" ,  "type" : "I" ,  "default" : 0 },
+    { "label" : "Wifi SSID" ,  "key" : "wifiSsid" ,  "type" : "C" ,  "length" : 32,  "default" : "test" },
+    { "label" : "Wifi Key" ,  "key" : "wifiKey" ,  "type" : "C" ,  "length" : 64,  "default" : "geheim" },
+    { "label" : "MQTT Broker" ,  "key" : "mqttBroker" ,  "type" : "C" ,  "length" : 64,  "default" : "broker.hottis.de" },
+    { "label" : "MQTT Username" ,  "key" : "mqttUser" ,  "type" : "C" ,  "length" : 32,  "default" : "esp1" },
+    { "label" : "MQTT Password" ,  "key" : "mqttPass" ,  "type" : "C" ,  "length" : 32,  "default" : "geheim" },
+    { "label" : "MQTT ClientId" ,  "key" : "mqttClientId" ,  "type" : "C" ,  "length" : 32,  "default" : "changeThis" },
+    { "label" : "MQTT Topic" ,  "key" : "mqttTopic" ,  "type" : "C" ,  "length" : 64,  "default" : "IoT/espThermometer2/location/measurement" },
+    { "label" : "MQTT Port" ,  "key" : "mqttPort" ,  "type" : "I" ,  "default" :8883},
+    { "label" : "Measure Period" ,  "key" : "measurePeriod" ,  "type" : "I" ,  "default" :300}
+]
+
+h_file = Template(file= configuration_h.tmpl , searchList=[{ configItems :configItems}])
+open('configuration.h','w').write(str(h_file))
+c_file = Template(file= configuration_c.tmpl , searchList=[{ configItems :configItems}])
+open('configuration.cpp','w').write(str(c_file))
+
+
+

+ +

+The two templates are: +

+ +

+

+
+typedef struct {
+#for $configItem in $configItems
+#if $configItem.type == 'C'
+  char ${configItem.key}[$configItem.length];
+#else if $configItem.type == 'I'
+  uint32_t $configItem.key;
+#end if
+#end for
+} tConfigBlock;
+
+extern const uint32_t MAGIC;
+extern tConfigBlock configBlock;
+
+void configServeIndex();
+void configServeGetConfiguration();
+void showConfiguration();
+
+
+
+

+ +

+And: +

+ +

+

+
+#raw
+#include 
+
+#include 
+#include 
+#include 
+
+#include "defines.h"
+#include "configuration.h"
+#end raw
+
+
+tConfigBlock configBlock;
+const uint32_t MAGIC = 0xC0DE0001;
+extern ESP8266WebServer webServer;
+
+bool configSaved = false;
+
+void configServeIndex() {
+  bool configValid = (configBlock.magic == MAGIC);
+
+  if (! configValid) {
+  #for $configItem in $configItems
+  #if $configItem.label != "_"
+  #if $configItem.type == "C"
+    strcpy(configBlock.$configItem.key, "$configItem.default");
+  #else if $configItem.type == "I"
+    configBlock.$configItem.key = $configItem.default;
+  #end if
+  #end if
+  #end for
+  }
+  
+  String buffer =
+  ""
+  "  "
+  "    ESP8266 Thermometer Configuration Page"
+  "  "
+  "  "
+  "    
ESP8266 Configuration Page
";
+  
+  if (configSaved) {
+    configSaved = false;
+    buffer += "
Configuration saved
";
+  }  
+  
+  buffer +=
+  "    
"
+  "      "
+  #for $configItem in $configItems
+  #if $configItem.label != "_"
+  "        "
+  "          "
+  "        "
+  #end if
+  #end for
+  "        "
+  "          "
+  "        "
+  "      
"
+  "            "
+  "          "
+  "            "
+  "          
"
+  "            "
+  "          
"
+  "    
"
+  "  "
+  "";
+
+  webServer.send(200, "text/html", buffer);
+
+
+#ifdef DEBUG
+  Serial.println("indexHtml request served");
+#endif    
+}
+
+void configServeGetConfiguration() {
+  String arg;
+
+  #for $configItem in $configItems
+  #if $configItem.label != "_"
+  arg = webServer.arg("$configItem.key");
+  #if $configItem.type == "C"
+  strcpy(configBlock.$configItem.key, arg.c_str());
+  #else if $configItem.type == "I"
+  configBlock.$configItem.key = atoi(arg.c_str());
+  #end if
+  #end if
+  #end for
+  
+  configBlock.magic = MAGIC;
+  
+  showConfiguration();
+  
+  EEPROM.begin(512);
+  EEPROM.put(EEPROM_ADDR, configBlock);  
+  EEPROM.commit();
+  
+  Serial.println("EEPROM saved");
+
+  configSaved = true;
+  webServer.sendHeader("Location", String("/"), true);
+  webServer.send(302, "text/plain", "");
+  //webServer.send(200, "text/html", "configuration saved");
+}
+  
+void showConfiguration() {
+  Serial.println("Configuration is");
+
+  #for $configItem in $configItems
+  Serial.print("$configItem.key = ");
+  Serial.println(configBlock.$configItem.key);
+    
+  #end for
+  
+  Serial.println("---");
+}
+
+
+

+ +

+Besides these generated files I also needed a framework to distinguish between "configuration mode" and "production mode" and in configuration mode to start the WiFi accesspoint. +

+ +

+Since I'm programming the ESP8266 in an Eclipse-based Arduino-environment, this is all done in the setup() and loop() function: +

+ +

+

+
+// Do not remove the include below
+#include "EspThermometer2.h"
+#include "defines.h"
+
+// #define ESP8266
+
+
+#include 
+
+#include "configuration.h"
+#include "productionMode.h"
+#include "configurationMode.h"
+
+
+
+ADC_MODE(ADC_VCC);
+
+
+
+bool configMode = false;
+
+uint32_t startTime = 0;
+
+
+void setup() {
+  startTime = millis();
+#ifdef DEBUG
+  Serial.begin(115200);
+  Serial.println("Starting ...");
+#endif
+
+  pinMode(CONFIG_SWITCH, INPUT_PULLUP);
+  pinMode(LED_PIN, OUTPUT);
+
+
+  EEPROM.begin(512);
+  EEPROM.get(EEPROM_ADDR, configBlock);
+
+
+  Serial.print("Magic: ");
+  Serial.println(configBlock.magic);
+
+  configMode = ((LOW == digitalRead(CONFIG_SWITCH)) || (configBlock.magic != MAGIC));
+
+  if (configMode) {
+#ifdef DEBUG
+  Serial.println("Configuration mode");
+#endif
+  	digitalWrite(LED_PIN, LOW);
+    setupConfigurationNetwork();
+    setupConfigurationServer();
+  } else {
+#ifdef DEBUG
+  Serial.println("Production mode");
+  Serial.println();
+  Serial.println();
+  showConfiguration();
+#endif
+
+	digitalWrite(LED_PIN, HIGH);
+    setupProduction();
+    setupConfigurationServer();
+  }
+
+#ifdef DEBUG
+  Serial.println("Started.");
+#endif
+}
+
+void loop() {
+  if (configMode) {
+    loopConfiguration();
+  } else {
+    loopProduction();
+  }
+}
+
+
+
+

+ +

+This code can be also found embedded into two of my projects. Find them at https://gitlab.com/wolutator/EspThermometer2 and https://gitlab.com/wolutator/TouchSwitch. +