adds ping to the end of the main loop in examples

examples/mqtt_cc3k/mqtt_cc3k.ino

@@ -105,16 +105,6 @@ void loop() {
   // function definition further below.
   MQTT_connect();
 
-  // Try to ping the MQTT server
-  /*
-  if (! mqtt.ping(3) ) {
-    // MQTT pings failed, let's reconnect by forcing a watchdog reset.
-    Serial.println("Ping fail! Resetting...");
-    Watchdog.enable(8000);
-    delay(10000);
-  }
-  */
-
   // this is our 'wait for incoming subscription packets' busy subloop
   Adafruit_MQTT_Subscribe *subscription;
   while ((subscription = mqtt.readSubscription(1000))) {
@@ -133,6 +123,12 @@ void loop() {
   } else {
     Serial.println(F("OK!"));
   }
+
+  // ping the server to keep the mqtt connection alive
+  if(! mqtt.ping()) {
+    Serial.println(F("MQTT Ping failed."));
+  }
+
 }
 
 // Function to connect and reconnect as necessary to the MQTT server.

examples/mqtt_esp8266/mqtt_esp8266.ino

@@ -90,14 +90,6 @@ void loop() {
   // function definition further below.
   MQTT_connect();
 
-  // Try to ping the MQTT server
-  /*
-  if (! mqtt.ping(3) ) {
-    // MQTT pings failed, lets reconnect
-    Serial.println("Ping fail!");
-  }
-  */
-
   // this is our 'wait for incoming subscription packets' busy subloop
   Adafruit_MQTT_Subscribe *subscription;
   while ((subscription = mqtt.readSubscription(1000))) {
@@ -117,7 +109,13 @@ void loop() {
     Serial.println(F("OK!"));
   }
 
+  // ping the server to keep the mqtt connection alive
+  if(! mqtt.ping()) {
+    mqtt.disconnect();
+  }
+
   delay(1000);
+
 }
 
 // Function to connect and reconnect as necessary to the MQTT server.

examples/mqtt_ethernet/mqtt_ethernet.ino

@@ -92,13 +92,6 @@ void loop() {
   // function definition further below.
   MQTT_connect();
 
-  // Try to ping the MQTT server
-  if (! mqtt.ping(3) ) {
-    // MQTT pings failed, let's reconnect by forcing a watchdog reset.
-    Serial.println("Ping fail! Resetting...");
-    delay(10000);
-  }
-
   // this is our 'wait for incoming subscription packets' busy subloop
   Adafruit_MQTT_Subscribe *subscription;
   while ((subscription = mqtt.readSubscription(1000))) {
@@ -117,6 +110,12 @@ void loop() {
   } else {
     Serial.println(F("OK!"));
   }
+
+  // ping the server to keep the mqtt connection alive
+  if(! mqtt.ping()) {
+    mqtt.disconnect();
+  }
+
 }
 
 // Function to connect and reconnect as necessary to the MQTT server.

examples/mqtt_fona/mqtt_fona.ino

@@ -113,30 +113,10 @@ void loop() {
   // Make sure to reset watchdog every loop iteration!
   Watchdog.reset();
 
-  // check if we're still connected
+  // Ensure the connection to the MQTT server is alive (this will make the first
-  if (!fona.TCPconnected() || (txfailures >= MAXTXFAILURES)) {
+  // connection and automatically reconnect when disconnected).  See the MQTT_connect
-    Serial.println(F("Connecting to MQTT..."));
+  // function definition further below.
-    int8_t ret, retries = 5;
+  MQTT_connect();
-    while (retries && (ret = mqtt.connect()) != 0) {
-       Serial.println(mqtt.connectErrorString(ret));
-       Serial.println(F("Retrying MQTT connection"));
-       retries--;
-       if (retries == 0) halt("Resetting system");
-       delay(5000);
-    }
-    Serial.println(F("MQTT Connected!"));
-    txfailures = 0;
-  }
-
-
-  // Try to ping the MQTT server
-  /*
-  if (! mqtt.ping(3) ) {
-    // MQTT pings failed, lets reconnect
-    Serial.println("Ping fail!");
-  }
-  */
-
 
   // this is our 'wait for incoming subscription packets' busy subloop
   Adafruit_MQTT_Subscribe *subscription;
@@ -158,4 +138,31 @@ void loop() {
     Serial.println(F("OK!"));
     txfailures = 0;
   }
+
+  // ping the server to keep the mqtt connection alive
+  if(! mqtt.ping()) {
+    Serial.println(F("MQTT Ping failed."));
+  }
+
+}
+
+// Function to connect and reconnect as necessary to the MQTT server.
+// Should be called in the loop function and it will take care if connecting.
+void MQTT_connect() {
+  int8_t ret;
+
+  // Stop if already connected.
+  if (mqtt.connected()) {
+    return;
+  }
+
+  Serial.print("Connecting to MQTT... ");
+
+  while ((ret = mqtt.connect()) != 0) { // connect will return 0 for connected
+    Serial.println(mqtt.connectErrorString(ret));
+    Serial.println("Retrying MQTT connection in 5 seconds...");
+    mqtt.disconnect();
+    delay(5000);  // wait 5 seconds
+  }
+  Serial.println("MQTT Connected!");
 }

examples/mqtt_yun/mqtt_yun.ino

@@ -74,14 +74,6 @@ void loop() {
   // function definition further below.
   MQTT_connect();
 
-  // Try to ping the MQTT server
-  /*
-  if (! mqtt.ping(3) ) {
-    // MQTT pings failed, lets reconnect
-    Console.println("Ping fail!");
-  }
-  */
-
   // this is our 'wait for incoming subscription packets' busy subloop
   Adafruit_MQTT_Subscribe *subscription;
   while ((subscription = mqtt.readSubscription(1000))) {
@@ -101,7 +93,13 @@ void loop() {
     Console.println(F("OK!"));
   }
 
+  // ping the server to keep the mqtt connection alive
+  if(! mqtt.ping()) {
+    Serial.println(F("MQTT Ping failed."));
+  }
+
   delay(1000);
+
 }
 
 // Function to connect and reconnect as necessary to the MQTT server.