//MASTER

#define button 8

int buttonState = 0;

void setup() {
  pinMode(button, INPUT);
  Serial.begin(9600);
}

void loop() {
 if(Serial.available() > 0){ 
 }
 
 buttonState = digitalRead(button);
 if (buttonState == HIGH) {
   Serial.write('1'); // Sends '1' to the master to turn on LED
 }
 else {
   Serial.write('0');
 }  
}