Hi, yout post is quit old but I changed your code a bit. Now it sends the status of both relays: long double last_heartbeat_time = millis(); long double HEARTBEAT_TIME = 30000; int oldValue = 0; bool state; MyMessage msg1a(1, V_STATUS); MyMessage msg1b; MyMessage msg2a(2, V_STATUS); MyMessage msg2b; void before() { for (int sensor = 1, pin = RELAY_1; sensor <= NUMBER_OF_RELAYS; sensor++, pin++) { // Then set relay pins in output mode pinMode(pin, OUTPUT); // Set relay to last known state (using eeprom storage) digitalWrite(pin, loadState(sensor) ? RELAY_ON : RELAY_OFF); } } void setup() { } void presentation() { // Send the sketch version information to the gateway and Controller sendSketchInfo("Relay", "1.0"); for (int sensor = 1, pin = RELAY_1; sensor <= NUMBER_OF_RELAYS; sensor++, pin++) { // Register all sensors to gw (they will be created as child devices) present(sensor, S_BINARY); } } void loop() { long double temp = (millis() - last_heartbeat_time); if (temp > HEARTBEAT_TIME) { // If it exceeds the heartbeat time then send a heartbeat sendHeartbeat(); send(msg1a.set(msg1b.getBool() ? 1 : 0)); send(msg2a.set(msg2b.getBool() ? 1 : 0)); last_heartbeat_time = millis(); Serial.println("Sent heartbeat" ); } } void receive(const MyMessage &message) { // We only expect one type of message from controller. But we better check anyway. if (message.type == V_STATUS) { // Change relay state digitalWrite(message.sensor - 1 + RELAY_1, message.getBool() ? RELAY_ON : RELAY_OFF); // Store state in eeprom saveState(message.sensor, message.getBool()); // Write some debug info Serial.print("Incoming change for sensor:"); Serial.print(message.sensor); Serial.print(", New status: "); Serial.println(message.getBool()); if (message.sensor == 1) { msg1b = message; } if (message.sensor == 2) { msg2b = message; } } } rg Denis