Added sendHeatbeat()

Allow a sensor to send a "dummy" message to controller to say "I'm still
alive!". The payload will be an incremental uint16.

libraries/MySensors/MyMessage.h

@@ -146,7 +146,8 @@ typedef enum {
 	I_BATTERY_LEVEL, I_TIME, I_VERSION, I_ID_REQUEST, I_ID_RESPONSE,
 	I_INCLUSION_MODE, I_CONFIG, I_FIND_PARENT, I_FIND_PARENT_RESPONSE,
 	I_LOG_MESSAGE, I_CHILDREN, I_SKETCH_NAME, I_SKETCH_VERSION,
-	I_REBOOT, I_GATEWAY_READY, I_REQUEST_SIGNING, I_GET_NONCE, I_GET_NONCE_RESPONSE
+	I_REBOOT, I_GATEWAY_READY, I_REQUEST_SIGNING, I_GET_NONCE, I_GET_NONCE_RESPONSE,
+	I_HEARTBEAT
 } mysensor_internal;
 
 

libraries/MySensors/MySensor.cpp

@@ -487,6 +487,11 @@ void MySensor::sendBatteryLevel(uint8_t value, bool enableAck) {
 	sendRoute(build(msg, nc.nodeId, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_BATTERY_LEVEL, enableAck).set(value));
 }
 
+void MySensor::sendHeartbeat(void) {
+	sendRoute(build(msg, nc.nodeId, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_HEARTBEAT, false).set(heartbeat++));
+
+}
+
 void MySensor::present(uint8_t childSensorId, uint8_t sensorType, const char *description, bool enableAck) {
 	sendRoute(build(msg, nc.nodeId, GATEWAY_ADDRESS, childSensorId, C_PRESENTATION, sensorType, enableAck).set(childSensorId==NODE_SENSOR_ID?LIBRARY_VERSION:description));
 }

libraries/MySensors/MySensor.h

@@ -219,6 +219,12 @@ class MySensor
 	 */
 	void sendBatteryLevel(uint8_t level, bool ack=false);
 
+	/**
+	 * Send a heartbeat message (I'm alive!) to the gateway/controller.
+	 * The payload will be an incremental 16 bit integer value starting at 1 when sensor is powered on.
+	 */
+	void sendHeartbeat(void);
+
 	/**
 	* Requests a value from gateway or some other sensor in the radio network.
 	* Make sure to add callback-method in begin-method to handle request responses.
@@ -373,6 +379,7 @@ class MySensor
 	char convBuf[MAX_PAYLOAD*2+1];
 #endif
 	uint8_t failedTransmissions;
+	uint16_t heartbeat;
     void (*timeCallback)(unsigned long); // Callback for requested time messages
     void (*msgCallback)(const MyMessage &); // Callback for incoming messages from other nodes and gateway.