//Note:- Use only non 0(Zero) Integers as Code #define Relay1 13 //Engine Pin #define Relay2 12 #define Relay3 11 #define Relay4 10 #define Relay5 9 #define Relay6 8 #define Relay7 7 #define Relay8 6 #define Relay9 5 #define Relay10 4 void setup() { Serial.begin(9600); digitalWrite(Relay1, LOW); digitalWrite(Relay2, LOW); digitalWrite(Relay3, LOW); digitalWrite(Relay4, LOW); digitalWrite(Relay5, LOW); digitalWrite(Relay6, LOW); digitalWrite(Relay7, LOW); digitalWrite(Relay8, LOW); digitalWrite(Relay9, LOW); digitalWrite(Relay10, LOW); pinMode(Relay1, OUTPUT); pinMode(Relay2, OUTPUT); pinMode(Relay3, OUTPUT); pinMode(Relay4, OUTPUT); pinMode(Relay5, OUTPUT); pinMode(Relay6, OUTPUT); pinMode(Relay7, OUTPUT); pinMode(Relay8, OUTPUT); pinMode(Relay9, OUTPUT); pinMode(Relay10, OUTPUT); Serial.println("Ready!"); } void loop() { int incomingByte = 0; if (Serial.available() > 0) { incomingByte = Serial.parseInt(); //Serial.println(incomingByte); if (incomingByte == 2) { digitalWrite(Relay1, HIGH); Serial.println("Device 1 ON."); } if (incomingByte == 1) { digitalWrite(Relay1, LOW); Serial.println("Device 1 OFF."); } if (incomingByte == 4) { digitalWrite(Relay2, HIGH); Serial.println("Device 2 ON."); } if (incomingByte == 3) { digitalWrite(Relay2, LOW); Serial.println("Device 2 OFF."); } if (incomingByte == 6) { digitalWrite(Relay3, HIGH); Serial.println("Device 3 ON."); } if (incomingByte == 5) { digitalWrite(Relay3, LOW); Serial.println("Device 3 OFF."); } if (incomingByte == 8) { digitalWrite(Relay4, HIGH); Serial.println("Device 4 ON."); } if (incomingByte == 7) { digitalWrite(Relay4, LOW); Serial.println("Device 4 OFF."); } if (incomingByte == 10) { digitalWrite(Relay5, HIGH); Serial.println("Device 5 ON."); } if (incomingByte == 9) { digitalWrite(Relay5, LOW); Serial.println("Device 5 OFF."); } if (incomingByte == 12) { digitalWrite(Relay6, HIGH); Serial.println("Device 6 ON."); } if (incomingByte == 11) { digitalWrite(Relay6, LOW); Serial.println("Device 6 OFF."); } if (incomingByte == 14) { digitalWrite(Relay7, HIGH); Serial.println("Device 7 ON."); } if (incomingByte == 13) { digitalWrite(Relay7, LOW); Serial.println("Device 7 OFF."); } if (incomingByte == 16) { digitalWrite(Relay8, HIGH); Serial.println("Device 8 ON."); } if (incomingByte == 15) { digitalWrite(Relay8, LOW); Serial.println("Device 8 OFF."); } if (incomingByte == 18) { digitalWrite(Relay9, HIGH); Serial.println("Device 9 ON."); } if (incomingByte == 17) { digitalWrite(Relay9, LOW); Serial.println("Device 9 OFF."); } if (incomingByte == 20) { digitalWrite(Relay10, HIGH); Serial.println("Device 10 ON."); } if (incomingByte == 19) { digitalWrite(Relay10, LOW); Serial.println("Device 10 OFF."); } } }