#include <SoftwareSerial.h>
SoftwareSerial mySerial(0, 1); // RX, TX

const int buttonPin = 7;     // the number of the pushbutton pin
const int ledPin =  8;      // the number of the LED pin

int incomingByte;
int buttonState = 0; 
char button_pressed = '0'; 

void setup() {
   pinMode(ledPin, OUTPUT);
   pinMode(buttonPin, INPUT);
   mySerial.begin(9600);
}

void loop() {
  
  buttonState = digitalRead(buttonPin);
  if (buttonState == LOW) {
    button_pressed = '1';
  }
  
  if (mySerial.available() > 0) {
    incomingByte = mySerial.read();
    if (incomingByte == 'A') {          
      mySerial.println(button_pressed);   
      
    }
    else if (incomingByte == 'K'){
      button_pressed = '0';
      digitalWrite(ledPin, HIGH);
      delay(200);
      digitalWrite(ledPin, LOW);
    }
  }
}