diff --git a/core/MyOTAFirmwareUpdate.cpp b/core/MyOTAFirmwareUpdate.cpp
index e30cf97..34e69e1 100644
--- a/core/MyOTAFirmwareUpdate.cpp
+++ b/core/MyOTAFirmwareUpdate.cpp
@@ -54,7 +54,7 @@ void firmwareOTAUpdateRequest() {
 		firmwareRequest.version = _fc.version;
 		firmwareRequest.block = (_fwBlock - 1);
 		OTA_DEBUG(PSTR("OTA:FRQ:FW REQ,T=%04X,V=%04X,B=%04X\n"),_fc.type,_fc.version,_fwBlock - 1); // request FW update block
-		_sendRoute(build(_msgTmp, _nc.nodeId, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_STREAM, ST_FIRMWARE_REQUEST, false).set(&firmwareRequest,sizeof(RequestFWBlock)));
+		_sendRoute(build(_msgTmp, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_STREAM, ST_FIRMWARE_REQUEST, false).set(&firmwareRequest,sizeof(RequestFWBlock)));
 	}
 }
 
@@ -137,7 +137,7 @@ void presentBootloaderInformation(){
 	// add bootloader information
 	reqFWConfig->BLVersion = MY_OTA_BOOTLOADER_VERSION;
 	_fwUpdateOngoing = false;
-	_sendRoute(build(_msgTmp, _nc.nodeId, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_STREAM, ST_FIRMWARE_CONFIG_REQUEST, false));	
+	_sendRoute(build(_msgTmp, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_STREAM, ST_FIRMWARE_CONFIG_REQUEST, false));	
 }
 // do a crc16 on the whole received firmware
 bool transportIsValidFirmware() {
diff --git a/core/MySensorsCore.cpp b/core/MySensorsCore.cpp
index cf45f49..d52e2c4 100644
--- a/core/MySensorsCore.cpp
+++ b/core/MySensorsCore.cpp
@@ -180,7 +180,7 @@ void _registerNode() {
 		uint8_t counter = MY_REGISTRATION_RETRIES;
 		// only proceed if register response received or retries exceeded
 		do {
-			_sendRoute(build(_msgTmp, _nc.nodeId, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_REGISTRATION_REQUEST, false).set(MY_CORE_VERSION));
+			_sendRoute(build(_msgTmp, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_REGISTRATION_REQUEST, false).set(MY_CORE_VERSION));
 		} while (!wait(2000, C_INTERNAL, I_REGISTRATION_RESPONSE) && counter--);
 
 	#else
@@ -217,7 +217,7 @@ void presentNode() {
 
 		// Send a configuration exchange request to controller
 		// Node sends parent node. Controller answers with latest node configuration
-		_sendRoute(build(_msgTmp, _nc.nodeId, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_CONFIG, false).set(_nc.parentNodeId));
+		_sendRoute(build(_msgTmp, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_CONFIG, false).set(_nc.parentNodeId));
 
 		// Wait configuration reply.
 		wait(2000, C_INTERNAL, I_CONFIG);
@@ -280,31 +280,31 @@ bool send(MyMessage &message, bool enableAck) {
 	}
 
 void sendBatteryLevel(uint8_t value, bool enableAck) {
-	_sendRoute(build(_msgTmp, _nc.nodeId, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_BATTERY_LEVEL, enableAck).set(value));
+	_sendRoute(build(_msgTmp, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_BATTERY_LEVEL, enableAck).set(value));
 }
 
 void sendHeartbeat(void) {
 	#if defined(MY_RADIO_FEATURE)
 		uint32_t heartbeat = transportGetHeartbeat();
-		_sendRoute(build(_msgTmp, _nc.nodeId, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_HEARTBEAT_RESPONSE, false).set(heartbeat));
+		_sendRoute(build(_msgTmp, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_HEARTBEAT_RESPONSE, false).set(heartbeat));
 	#endif
 }
 
 void present(uint8_t childSensorId, uint8_t sensorType, const char *description, bool enableAck) {
-	_sendRoute(build(_msgTmp, _nc.nodeId, GATEWAY_ADDRESS, childSensorId, C_PRESENTATION, sensorType, enableAck).set(childSensorId==NODE_SENSOR_ID?MYSENSORS_LIBRARY_VERSION:description));
+	_sendRoute(build(_msgTmp, GATEWAY_ADDRESS, childSensorId, C_PRESENTATION, sensorType, enableAck).set(childSensorId==NODE_SENSOR_ID?MYSENSORS_LIBRARY_VERSION:description));
 }
 
 void sendSketchInfo(const char *name, const char *version, bool enableAck) {
-	if (name) _sendRoute(build(_msgTmp, _nc.nodeId, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_SKETCH_NAME, enableAck).set(name));
-    if (version) _sendRoute(build(_msgTmp, _nc.nodeId, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_SKETCH_VERSION, enableAck).set(version));
+	if (name) _sendRoute(build(_msgTmp, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_SKETCH_NAME, enableAck).set(name));
+    if (version) _sendRoute(build(_msgTmp, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_SKETCH_VERSION, enableAck).set(version));
 }
 
 void request(uint8_t childSensorId, uint8_t variableType, uint8_t destination) {
-	_sendRoute(build(_msgTmp, _nc.nodeId, destination, childSensorId, C_REQ, variableType, false).set(""));
+	_sendRoute(build(_msgTmp, destination, childSensorId, C_REQ, variableType, false).set(""));
 }
 
 void requestTime() {
-	_sendRoute(build(_msgTmp, _nc.nodeId, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_TIME, false).set(""));
+	_sendRoute(build(_msgTmp, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_TIME, false).set(""));
 }
 
 // Message delivered through _msg
@@ -349,7 +349,7 @@ bool _processInternalMessages() {
 					// Clears child relay data for this node
 					setIndication(INDICATION_CLEAR_ROUTING);
 					transportClearRoutingTable();
-					_sendRoute(build(_msgTmp, _nc.nodeId, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_CHILDREN, false).set("ok"));
+					_sendRoute(build(_msgTmp, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_CHILDREN, false).set("ok"));
 				}
 			#endif
 		}
@@ -363,23 +363,23 @@ bool _processInternalMessages() {
 						if (route != BROADCAST_ADDRESS) {
 							debug(PSTR("MCO:PIM:ROUTE N=%d,R=%d\n"), cnt, route);
 							uint8_t outBuf[2] = { (uint8_t)cnt,route };
-							_sendRoute(build(_msgTmp, _nc.nodeId, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_DEBUG, false).set(outBuf, 2));
+							_sendRoute(build(_msgTmp, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_DEBUG, false).set(outBuf, 2));
 							wait(200);
 						}
 					}
 				#endif
 				}
 				else if (debug_msg == 'V') {	// CPU voltage
-					_sendRoute(build(_msgTmp, _nc.nodeId, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_DEBUG, false).set(hwCPUVoltage()));
+					_sendRoute(build(_msgTmp, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_DEBUG, false).set(hwCPUVoltage()));
 				}
 				else if (debug_msg == 'F') {	// CPU frequency in 1/10Mhz
-					_sendRoute(build(_msgTmp, _nc.nodeId, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_DEBUG, false).set(hwCPUFrequency()));
+					_sendRoute(build(_msgTmp, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_DEBUG, false).set(hwCPUFrequency()));
 				}
 				else if (debug_msg == 'M') {	// free memory
-					_sendRoute(build(_msgTmp, _nc.nodeId, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_DEBUG, false).set(hwFreeMem()));
+					_sendRoute(build(_msgTmp, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_DEBUG, false).set(hwFreeMem()));
 				}
 				else if (debug_msg == 'E') {	// clear MySensors eeprom area and reboot
-					_sendRoute(build(_msgTmp, _nc.nodeId, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_DEBUG, false).set("ok"));
+					_sendRoute(build(_msgTmp, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_DEBUG, false).set("ok"));
 					for (int i = EEPROM_START; i<EEPROM_LOCAL_CONFIG_ADDRESS; i++) hwWriteConfig(i, 0xFF);
 					setIndication(INDICATION_REBOOT);
 					hwReboot();
@@ -405,7 +405,7 @@ bool _processInternalMessages() {
 						// delay for fast GW and slow nodes
 						delay(5);
 					#endif
-					_sendRoute(build(_msgTmp, _nc.nodeId, _msg.sender, NODE_SENSOR_ID, C_INTERNAL, I_REGISTRATION_RESPONSE, false).set(approveRegistration));
+					_sendRoute(build(_msgTmp, _msg.sender, NODE_SENSOR_ID, C_INTERNAL, I_REGISTRATION_RESPONSE, false).set(approveRegistration));
 				#else
 					return false;	// processing of this request via controller
 				#endif
@@ -572,7 +572,7 @@ void nodeLock(const char* str) {
 		#if defined(ARDUINO_ARCH_ESP8266)
 			yield();
 		#endif
-		_sendRoute(build(_msgTmp, _nc.nodeId, GATEWAY_ADDRESS, NODE_SENSOR_ID,C_INTERNAL, I_LOCKED, false).set(str));
+		_sendRoute(build(_msgTmp, GATEWAY_ADDRESS, NODE_SENSOR_ID,C_INTERNAL, I_LOCKED, false).set(str));
 		#if defined(MY_RADIO_FEATURE)
 			transportPowerDown();
 			debug(PSTR("MCO:NLK:TPD\n"));	// power down transport
diff --git a/core/MySensorsCore.h b/core/MySensorsCore.h
index 390ad82..6ccc80d 100644
--- a/core/MySensorsCore.h
+++ b/core/MySensorsCore.h
@@ -400,8 +400,8 @@ void loop() __attribute__((weak));
 
 
 // Inline function and macros
-static inline MyMessage& build(MyMessage &msg, uint8_t sender, uint8_t destination, uint8_t sensor, uint8_t command, uint8_t type, bool enableAck) {
-	msg.sender = sender;
+static inline MyMessage& build(MyMessage &msg, const uint8_t destination, const uint8_t sensor, const uint8_t command, const uint8_t type, const bool enableAck) {
+	msg.sender = _nc.nodeId;
 	msg.destination = destination;
 	msg.sensor = sensor;
 	msg.type = type;
@@ -411,7 +411,7 @@ static inline MyMessage& build(MyMessage &msg, uint8_t sender, uint8_t destinati
 	return msg;
 }
 
-static inline MyMessage& buildGw(MyMessage &msg, uint8_t type) {
+static inline MyMessage& buildGw(MyMessage &msg, const uint8_t type) {
 	msg.sender = GATEWAY_ADDRESS;
 	msg.destination = GATEWAY_ADDRESS;
 	msg.sensor = NODE_SENSOR_ID;
diff --git a/core/MySigning.cpp b/core/MySigning.cpp
index c0013b7..3bc484e 100644
--- a/core/MySigning.cpp
+++ b/core/MySigning.cpp
@@ -106,7 +106,7 @@ static bool skipSign(MyMessage &msg) {
 // Helper to prepare a signing presentation message
 static void prepareSigningPresentation(MyMessage &msg, uint8_t destination) {
 	// Only supports version 1 for now
-	build(msg, _nc.nodeId, destination, NODE_SENSOR_ID, C_INTERNAL, I_SIGNING_PRESENTATION, false).set("");
+	build(msg, destination, NODE_SENSOR_ID, C_INTERNAL, I_SIGNING_PRESENTATION, false).set("");
 	mSetLength(msg, 2);
 	mSetPayloadType(msg, P_CUSTOM);		// displayed as hex
 	msg.data[0] = SIGNING_PRESENTATION_VERSION_1;
@@ -188,8 +188,7 @@ bool signerProcessInternal(MyMessage &msg) {
 #if defined(MY_SIGNING_ATSHA204)
 			if (signerAtsha204GetNonce(msg)) {
 #endif
-				if (!_sendRoute(build(msg, _nc.nodeId, msg.sender, NODE_SENSOR_ID,
-					C_INTERNAL, I_NONCE_RESPONSE, false))) {
+				if (!_sendRoute(build(msg, msg.sender, NODE_SENSOR_ID, C_INTERNAL, I_NONCE_RESPONSE, false))) {
 					SIGN_DEBUG(PSTR("Failed to transmit nonce!\n"));
 				} else {
 					SIGN_DEBUG(PSTR("Transmitted nonce\n"));
@@ -315,8 +314,7 @@ bool signerSignMsg(MyMessage &msg) {
 		} else {
 			// Send nonce-request
 			_signingNonceStatus=SIGN_WAITING_FOR_NONCE;
-			if (!_sendRoute(build(_msgSign, _nc.nodeId, msg.destination, msg.sensor,
-				C_INTERNAL, I_NONCE_REQUEST, false).set(""))) {
+			if (!_sendRoute(build(_msgSign, msg.destination, msg.sensor, C_INTERNAL, I_NONCE_REQUEST, false).set(""))) {
 				SIGN_DEBUG(PSTR("Failed to transmit nonce request!\n"));
 				return false;
 			}
diff --git a/core/MyTransport.cpp b/core/MyTransport.cpp
index 7200558..2532511 100644
--- a/core/MyTransport.cpp
+++ b/core/MyTransport.cpp
@@ -134,7 +134,7 @@ void stParentTransition(void)  {
 		_nc.distance = DISTANCE_INVALID;	// Set distance to max and invalidate parent node ID
 		_nc.parentNodeId = AUTO;
 		// Broadcast find parent request
-		(void)transportRouteMessage(build(_msgTmp, _nc.nodeId, BROADCAST_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_FIND_PARENT_REQUEST, false).set(""));
+		(void)transportRouteMessage(build(_msgTmp, BROADCAST_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_FIND_PARENT_REQUEST, false).set(""));
 	#endif
 }
 
@@ -181,7 +181,7 @@ void stIDTransition(void) {
 		// send ID request
 		setIndication(INDICATION_REQ_NODEID);
 		TRANSPORT_DEBUG(PSTR("TSM:ID:REQ\n"));	// request node ID
-		(void)transportRouteMessage(build(_msgTmp, _nc.nodeId, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_ID_REQUEST, false).set(""));
+		(void)transportRouteMessage(build(_msgTmp, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_ID_REQUEST, false).set(""));
 	}
 }
 
@@ -214,7 +214,7 @@ void stUplinkTransition(void) {
 		setIndication(INDICATION_CHECK_UPLINK);
 		_transportSM.pingResponse = INVALID_HOPS;
 		_transportSM.pingActive = true;
-		(void)transportRouteMessage(build(_msgTmp, _nc.nodeId, GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_PING, false).set((uint8_t)1));
+		(void)transportRouteMessage(build(_msgTmp,GATEWAY_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_PING, false).set((uint8_t)1));
 	#endif
 }
 
@@ -265,7 +265,7 @@ void stReadyUpdate(void) {
 		if (hwMillis() - _lastNetworkDiscovery > MY_TRANSPORT_DISCOVERY_INTERVAL_MS) {
 			_lastNetworkDiscovery = hwMillis();
 			TRANSPORT_DEBUG(PSTR("TSM:READY:NWD REQ\n"));	// send transport network discovery
-			(void)transportRouteMessage(build(_msgTmp, GATEWAY_ADDRESS, BROADCAST_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_DISCOVER_REQUEST, false).set(""));
+			(void)transportRouteMessage(build(_msgTmp, BROADCAST_ADDRESS, NODE_SENSOR_ID, C_INTERNAL, I_DISCOVER_REQUEST, false).set(""));
 		}
 	#else
 		if (_transportSM.failedUplinkTransmissions > MY_TRANSPORT_MAX_TX_FAILURES) {
@@ -507,7 +507,7 @@ uint8_t transportPingNode(const uint8_t targetId) {
 		else {
 			_transportSM.pingActive = true;
 			_transportSM.pingResponse = INVALID_HOPS;
-			(void)transportRouteMessage(build(_msgTmp, _nc.nodeId, targetId, NODE_SENSOR_ID, C_INTERNAL, I_PING, false).set((uint8_t)1));
+			(void)transportRouteMessage(build(_msgTmp, targetId, NODE_SENSOR_ID, C_INTERNAL, I_PING, false).set((uint8_t)1));
 			// Wait for ping reply or timeout
 			(void)transportWait(2000, C_INTERNAL, I_PONG);
 		}
@@ -647,7 +647,7 @@ void transportProcessMessage(void) {
 						// delay for fast GW and slow nodes
 						delay(5);
 					#endif
-					(void)transportRouteMessage(build(_msgTmp, _nc.nodeId, sender, NODE_SENSOR_ID, C_INTERNAL, I_PONG, false).set((uint8_t)1));
+					(void)transportRouteMessage(build(_msgTmp, sender, NODE_SENSOR_ID, C_INTERNAL, I_PONG, false).set((uint8_t)1));
 					return; // no further processing required
 				}
 				if (type == I_PONG) {
@@ -700,7 +700,7 @@ void transportProcessMessage(void) {
 							TRANSPORT_DEBUG(PSTR("TSF:MSG:GWL OK\n")); // GW uplink ok
 							// random delay minimizes collisions
 							delay(hwMillis() & 0x3ff);
-							(void)transportRouteMessage(build(_msgTmp, _nc.nodeId, sender, NODE_SENSOR_ID, C_INTERNAL, I_FIND_PARENT_RESPONSE, false).set(_nc.distance));
+							(void)transportRouteMessage(build(_msgTmp, sender, NODE_SENSOR_ID, C_INTERNAL, I_FIND_PARENT_RESPONSE, false).set(_nc.distance));
 						}
 						else {
 							TRANSPORT_DEBUG(PSTR("!TSF:MSG:GWL FAIL\n")); // GW uplink fail, do not respond to parent request
@@ -718,7 +718,7 @@ void transportProcessMessage(void) {
 					if (last == _nc.parentNodeId) {
 						// random wait to minimize collisions
 						delay(hwMillis() & 0x3ff);
-						(void)transportRouteMessage(build(_msgTmp, _nc.nodeId, sender, NODE_SENSOR_ID, C_INTERNAL, I_DISCOVER_RESPONSE, false).set(_nc.parentNodeId));
+						(void)transportRouteMessage(build(_msgTmp, sender, NODE_SENSOR_ID, C_INTERNAL, I_DISCOVER_RESPONSE, false).set(_nc.parentNodeId));
 						// no return here (for fwd if repeater)
 					}
 				}