int led = 3; int button =2 ; // the setup function runs once when you press reset or power the board void setup() { // initialize digital pin LED_BUILTIN as an output. pinMode(led, OUTPUT); pinMode(button, INPUT); Serial.begin(9600); } // the loop function runs over and over again forever void loop() { if (Serial.available() > 0) { char ledstate = Serial.read(); if ( ledstate == '1') { digitalWrite(led, ledstate); } if (ledstate =='0') { digitalWrite(led, LOW); } } int buttonState = digitalRead(button); if ( buttonState == HIGH) { Serial.println("Button is Pressed "); } }