Added ability to connect to mqtt server by url. Fixed mqtt client

connect bug. #355

libraries/MySensors/MySensor.h

@@ -179,9 +179,10 @@
 	#endif
 	// GATEWAY - COMMON FUNCTIONS
 	// We only support MQTT Client using W5100 and ESP8266 at the moment
-	#if !defined(MY_CONTROLLER_IP_ADDRESS)
-		#error You must specify MY_CONTROLLER_IP_ADDRESS (MQTT broker address)
+	#if !(defined(MY_CONTROLLER_URL_ADDRESS) || defined(MY_CONTROLLER_IP_ADDRESS))
+		#error You must specify MY_CONTROLLER_IP_ADDRESS or MY_CONTROLLER_URL_ADDRESS
 	#endif
+
 	#if !defined(MY_MQTT_PUBLISH_TOPIC_PREFIX)
 		#error You must specify a topic publish prefix MY_MQTT_PUBLISH_TOPIC_PREFIX for this MQTT client
 	#endif

libraries/MySensors/core/MyGatewayTransportEthernet.cpp

@@ -156,7 +156,11 @@ bool gatewayTransportSend(MyMessage &message)
 			ret = _ethernetServer.endPacket();
 		#else
 			EthernetClient client;
-			if (client.connect(_ethernetControllerIP, MY_PORT)) {
+			#if defined(MY_CONTROLLER_URL_ADDRESS)
+				if (client.connect(MY_CONTROLLER_URL_ADDRESS, MY_PORT)) {
+			#else
+				if (client.connect(_ethernetControllerIP, MY_PORT)) {
+			#endif
 				client.write(_ethernetMsg, strlen(_ethernetMsg));
 				client.stop();
 			}

libraries/MySensors/core/MyGatewayTransportMQTTClient.cpp

@@ -28,7 +28,9 @@
 uint8_t protocolH2i(char c);
 
 
-IPAddress _brokerIp(MY_CONTROLLER_IP_ADDRESS);
+#if defined MY_CONTROLLER_IP_ADDRESS
+  IPAddress _brokerIp(MY_CONTROLLER_IP_ADDRESS);
+#endif
 
 #if defined(MY_GATEWAY_ESP8266)
 	#define EthernetClient WiFiClient
@@ -46,6 +48,7 @@ IPAddress _brokerIp(MY_CONTROLLER_IP_ADDRESS);
 
 EthernetClient _ethClient;
 PubSubClient _client(_ethClient);
+bool _connecting = true;
 bool _available = false;
 char _convBuffer[MAX_PAYLOAD*2+1];
 char _fmtBuffer[MY_GATEWAY_MAX_SEND_LENGTH];
@@ -152,7 +155,13 @@ bool reconnectMQTT() {
 }
 
 bool gatewayTransportInit() {
-	_client.setServer(_brokerIp, MY_PORT);
+	_connecting = true;
+	#if defined(MY_CONTROLLER_IP_ADDRESS)
+		_client.setServer(_brokerIp, MY_PORT);
+	#else
+		_client.setServer(MY_CONTROLLER_URL_ADDRESS, MY_PORT);
+	#endif
+
 	_client.setCallback(incomingMQTT);
 
   	#if defined(MY_GATEWAY_ESP8266)
@@ -166,30 +175,42 @@ bool gatewayTransportInit() {
 			MY_SERIALDEVICE.print(".");
 			yield();
 		}
-		MY_SERIALDEVICE.print(F("IP: "));
+		MY_SERIALDEVICE.print("IP: ");
 		MY_SERIALDEVICE.println(WiFi.localIP());
 	#else
 		#ifdef MY_IP_ADDRESS
 			Ethernet.begin(_clientMAC, _clientIp);
-			MY_SERIALDEVICE.print(F("IP: "));
-			MY_SERIALDEVICE.println(Ethernet.localIP());
 		#else
 			// Get IP address from DHCP
-			Ethernet.begin(_clientMAC);
-			MY_SERIALDEVICE.print(F("IP: "));
+			if (!Ethernet.begin(_clientMAC))
+			{
+				MY_SERIALDEVICE.print("DHCP FAILURE...");
+				_connecting = false;
+				return false;
+			}
+			MY_SERIALDEVICE.print("IP: ");
 			MY_SERIALDEVICE.println(Ethernet.localIP());
-		#endif /* IP_ADDRESS_DHCP */
+		#endif
+
 		// give the Ethernet interface a second to initialize
 		// TODO: use HW delay
 		wait(1000);
 	#endif
+	_connecting = false;
 	return true;
 }
 
 
 bool gatewayTransportAvailable() {
+	if (_connecting)
+		return false;
+
+	//keep lease on dhcp address
+	//Ethernet.maintain();
 	if (!_client.connected()) {
-		reconnectMQTT();
+		//reinitialise client
+		if (gatewayTransportInit())
+			reconnectMQTT();
 		return false;
 	}
 	_client.loop();

libraries/MySensors/examples/GatewayW5100MQTTClient/GatewayW5100MQTTClient.ino

@@ -103,8 +103,8 @@
 #define MY_IP_GATEWAY_ADDRESS 192,168,178,1
 #define MY_IP_SUBNET_ADDRESS 255,255,255,0
 
-
-// MQTT broker ip address.  
+// MQTT broker ip address or url. Define one or the other. 
+//#define MY_CONTROLLER_URL_ADDRESS "m20.cloudmqtt.com"
 #define MY_CONTROLLER_IP_ADDRESS 192, 168, 178, 68
 
 // The MQTT broker port to to open