#include <Arduino.h>

#define LED_Red 2
#define LED_Yellow 3
#define LED_Green 4

void setup() {
  pinMode(LED_Red, OUTPUT);
  pinMode(LED_Yellow, OUTPUT);
  pinMode(LED_Green, OUTPUT);
}

void loop() {
  // จากซ้ายไปขวา
  digitalWrite(LED_Red, HIGH);
  delay(1000);
  digitalWrite(LED_Red, LOW);

  digitalWrite(LED_Yellow, HIGH);
  delay(1000);
  digitalWrite(LED_Yellow, LOW);

  digitalWrite(LED_Green, HIGH);
  delay(1000);
  digitalWrite(LED_Green, LOW);

  // จากขวาไปซ้าย
  digitalWrite(LED_Green, HIGH);
  delay(1000);
  digitalWrite(LED_Green, LOW);

  digitalWrite(LED_Yellow, HIGH);
  delay(1000);
  digitalWrite(LED_Yellow, LOW);

  digitalWrite(LED_Red, HIGH);
  delay(1000);
  digitalWrite(LED_Red, LOW);
}