#define BUTTON_S1 12  // ESP32 pin GPIO13, which connected to button
#define BUTTON_S2 13
#define BUTTON_S3 14 
#define STOP 27   
#define LED_S1    2
#define LED_S2    4
#define LED_S3    15
int button1_state;
int button2_state;
int button3_state;
int STOP_S ;

void setup() {
  
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  pinMode(LED_S1, OUTPUT);
  pinMode(LED_S2, OUTPUT);
  pinMode(LED_S3, OUTPUT);
  pinMode(BUTTON_S1, INPUT_PULLUP);
  pinMode(BUTTON_S2, INPUT_PULLUP);
  pinMode(BUTTON_S3, INPUT_PULLUP);
  pinMode(STOP, INPUT_PULLUP);
}

void loop() {

button1_state = digitalRead(BUTTON_S1);
button2_state = digitalRead(BUTTON_S2);
button3_state = digitalRead(BUTTON_S3);
STOP_S        = digitalRead(STOP);
if(button1_state ==LOW)
{
   digitalWrite(LED_S1,HIGH );
 
}

if(button2_state ==LOW)
{
   digitalWrite(LED_S2,HIGH );
   

}

if(button3_state ==LOW)
{
   digitalWrite(LED_S3,HIGH );
  
}

if(STOP_S ==LOW)
{
   digitalWrite(LED_S1,LOW );
   digitalWrite(LED_S2,LOW );
   digitalWrite(LED_S3,LOW );
 
}

}