int incomingInt = 0; void setup() { Serial.begin(9600); Serial.setTimeout(1000); pinMode(7, OUTPUT); pinMode(5, OUTPUT); } void loop() { if (Serial.available() > 0) { incomingInt = Serial.parseInt(); if (incomingInt == 500) { digitalWrite(5, HIGH); }else digitalWrite(5, LOW); if (incomingInt == 422) { digitalWrite(7, HIGH); }else digitalWrite(7, LOW); Serial.println(incomingInt); } }