Adding to repo

30_interface_mqtt.ino

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+#ifdef ENABLE_MQTT
+
+/*
+ * Define a function newcmd in your module to be able to accept mqtt commands
+ * Syntax and parameters are like this:
+ */
+void newcmd(String cmd);
+void module_message(const String& shorttopic, const String& message);
+
+#include <PubSubClient.h>
+    
+// Setup the MQTT client class by passing in the WiFi client and MQTT server and login details.
+  PubSubClient mqtt(net);
+String deviceprefix;
+
+const char* fingerprint = "EA:2A:2B:80:C1:00:57:35:66:26:FF:FC:FA:27:EA:5F:3D:91:5A:F9";
+
+long logtimerMillis = 0;
+
+void mqtt_subscribe(const String& topic) {
+  mqtt.subscribe(topic.c_str());
+  PRINTLN_SERIAL("Subscribed to " + topic);
+}
+  
+void mqtt_publish(const String& topic, const String& message) {
+  mqtt.publish(topic.c_str(), message.c_str());
+   PRINTLN_SERIAL("Published " + topic + ": " + message);
+}
+
+/*
+ * Callback routine is called when a topic we subscribed to got a message
+ */
+void mqtt_callback(char* topic, byte* payload, unsigned int length) {
+  String fulltopic((char*)0);
+  String shorttopic((char*)0);
+  String message((char*)0);
+  
+  fulltopic.reserve(strlen(topic));
+  fulltopic = String(topic);
+
+  // If deviceprefix is in topic, subtract it
+  // Could do a similar thing for grouptopics if we implement them
+  shorttopic.reserve(strlen(topic));
+  shorttopic = String(topic);
+  shorttopic.replace(deviceprefix, "");
+
+  // Decode message into string
+  message.reserve(length);
+  for (int i = 0; i < length; i++) {
+    message += (char)payload[i];
+  }
+  PRINT_SERIAL(F("Received MQTT "));
+  APPEND_SERIAL(fulltopic);
+  APPEND_SERIAL(F(": "));
+  APPENDLN_SERIAL(message);
+
+  // Deal with global topic messages
+  if(fulltopic.equals(MQTT_PREFIX "ping")) {
+    mqtt_publish(deviceprefix + "pong", "This is " + settings.name + " v" + FW_VERSION + " at " + settings.ip);
+
+  // Next quietly ignore all the things we send out ourselves
+  } else if(shorttopic.equals(F("pong"))) { 
+    // Ignore quietly
+    //NOP; // delay 62.5ns on a 16MHz AtMega
+  } else if(shorttopic.equals(F("log"))) {  
+    // Ignore quietly
+    //NOP; // delay 62.5ns on a 16MHz AtMega
+
+  // And now to add a catchall to hand off to other module
+  } else {
+    module_message(shorttopic, message);
+  }
+}
+
+void WifiMQTTconnect() {
+  
+  if(WiFi.status() != WL_CONNECTED) {
+    PRINTLN_SERIAL("Wifi not connected, connecting...");
+    WiFi.mode(WIFI_STA);  // Weird MQTT connection bug, https://github.com/knolleary/pubsubclient/issues/138#issuecomment-326113915  
+    WiFi.begin(WLAN_SSID, WLAN_PASS);
+    while (WiFi.status() != WL_CONNECTED) {
+      PRINTLN_SERIAL("Waiting for Wifi...");
+      delay(500);
+    }
+    settings.ip = WiFi.localIP().toString();
+    PRINTLN_SERIAL("Wifi connected");  
+  }
+
+  PRINT_SERIAL("Setting time using SNTP");
+  configTime(-5 * 3600, 0, "pool.ntp.org", "time.nist.gov");
+  now = time(nullptr);
+  while (now < 1510592825) {
+    delay(500);
+    APPEND_SERIAL(".");
+    now = time(nullptr);
+  }
+  APPENDLN_SERIAL(" done!");
+  struct tm timeinfo;
+  gmtime_r(&now, &timeinfo);
+  PRINT_SERIAL("Current time: ");
+  APPENDLN_SERIAL(asctime(&timeinfo));
+  net.setInsecure();  // verification options set to none
+  mqtt.setServer(MQTT_SERVER, MQTT_SERVERPORT);
+  mqtt.setCallback(mqtt_callback);
+  
+  if(!mqtt.connected()) {
+    while (!mqtt.connected()) {
+      PRINTLN_SERIAL("MQTT not connected, connecting...");
+            
+      // Attempt to connect
+      // Note - the default maximum packet size is 128 bytes. If the
+      // combined length of clientId, username and password exceed this,
+      // you will need to increase the value of MQTT_MAX_PACKET_SIZE in
+      // PubSubClient.h
+      if (mqtt.connect(settings.name.c_str(), MQTT_USERNAME, MQTT_PASSWORD)) {
+        PRINTLN_SERIAL("MQTT connected");
+      } else {
+        PRINTLN_SERIAL("MQTT connection failed, rc=" + String(mqtt.state()) + "...");
+        delay(10000); // @@@FIXME@@@ delays are not cool
+      }
+    }
+      
+    // (re)subscribe to the topics we need
+    deviceprefix = MQTT_PREFIX;
+    deviceprefix = deviceprefix + settings.name + "/";
+      
+    mqtt_subscribe(MQTT_PREFIX "ping");   // global topic: send a ping, and we will respond with some device info
+    mqtt_subscribe(deviceprefix + "#");
+    mqtt_publish(deviceprefix + "log", "Booting up " + settings.name + " running v" + FW_VERSION + " at " + settings.ip);
+    mqtt_publish(deviceprefix + "log", "Free Heap: " + String(ESP.getFreeHeap()));
+
+  }
+}
+
+void mqtt_setup() {
+  PRINTLN_SERIAL(devname + "initialising module MQTT");
+}
+
+void mqtt_loop() {
+  long currentMillis = millis();
+  
+  // Check for MQTT instructions
+  if(!mqtt.connected()) {
+    WifiMQTTconnect();
+  } else {
+    mqtt.loop();
+
+    // every 5 minutes (300000 milliseconds)
+    if(currentMillis - logtimerMillis > 300000) {
+      // reset timer
+      logtimerMillis = currentMillis;
+      // log something
+      mqtt_publish(deviceprefix + "log", "Free Heap: " + String(ESP.getFreeHeap()));
+    }
+  }
+}
+
+#endif