//#define LED 4
int LED = 4;
int LED_pin = 3 ;
#define LED_pin1 D4
 //  blink 0.5 S
  /*
   Test esp 8266 by saruta wongkasai 
   industrial engineering KSU 




  */

void setup() {
  pinMode(LED, OUTPUT);
  pinMode(LED_pin,INPUT);
}

void loop() {
  digitalWrite(LED, HIGH);
  delay(500);
  digitalWrite(LED, LOW);
  delay(500);
}