/* ___ ___ ___ _ _ ___ ___ ____ ___ ____ * / _ \ /___)/ _ \| | | |/ _ \ / _ \ / ___) _ \| \ *| |_| |___ | |_| | |_| | |_| | |_| ( (__| |_| | | | | * \___/(___/ \___/ \__ |\___/ \___(_)____)___/|_|_|_| * (____/ * Remotely control LED with NodeMCU through MQTT IOT broker * Tutorial URL http://osoyoo.com/2016/11/25/remotely-control-led-with-nodemcu-through-mqtt-iot-broker/ * CopyRight John Yu */ #include #include // Define NodeMCU D3 pin connect to LED #define LED_PIN D3 // Update these with values suitable for your network. const char* ssid = "your_wifi_hotspot"; const char* password = "your_wifi_password"; const char* mqtt_server = "broker.mqtt-dashboard.com"; //const char* mqtt_server = "iot.eclipse.org"; WiFiClient espClient; PubSubClient client(espClient); long lastMsg = 0; char msg[50]; int value = 0; void setup_wifi() { delay(100); // We start by connecting to a WiFi network Serial.print("Connecting to "); Serial.println(ssid); WiFi.begin(ssid, password); while (WiFi.status() != WL_CONNECTED) { delay(500); Serial.print("."); } randomSeed(micros()); Serial.println(""); Serial.println("WiFi connected"); Serial.println("IP address: "); Serial.println(WiFi.localIP()); } void callback(char* topic, byte* payload, unsigned int length) { Serial.print("Command from MQTT broker is : ["); Serial.print(topic); int p =(char)payload[0]-'0'; // if MQTT comes a 0 turn off LED on D2 if(p==0) { digitalWrite(LED_PIN, LOW); Serial.println(" Turn Off LED! " ); } // if MQTT comes a 1, turn on LED on pin D2 if(p==1) { digitalWrite(LED_PIN, HIGH); Serial.println(" Turn On LED! " ); } Serial.println(); } //end callback void reconnect() { // Loop until we're reconnected while (!client.connected()) { Serial.print("Attempting MQTT connection..."); // Create a random client ID String clientId = "ESP8266Client-"; clientId += String(random(0xffff), HEX); // Attempt to connect //if you MQTT broker has clientID,username and password //please change following line to if (client.connect(clientId,userName,passWord)) if (client.connect(clientId.c_str())) { Serial.println("connected"); //once connected to MQTT broker, subscribe command if any client.subscribe("OsoyooCommand"); } else { Serial.print("failed, rc="); Serial.print(client.state()); Serial.println(" try again in 5 seconds"); // Wait 6 seconds before retrying delay(6000); } } } //end reconnect() void setup() { Serial.begin(115200); setup_wifi(); client.setServer(mqtt_server, 1883); client.setCallback(callback); pinMode(LED_PIN, OUTPUT); digitalWrite(LED_PIN, LOW); } void loop() { if (!client.connected()) { reconnect(); } client.loop(); }