#include <Arduino.h>
void setup()
{
  pinMode(25, OUTPUT);
  pinMode(26, OUTPUT);
  pinMode(27, OUTPUT);
}

void loop()
{
  lampu(1, 0, 0);
  delay(1000);
  lampu(0, 1, 0);
  delay(1000);
  lampu(0, 0, 1);
  delay(1000);
}

void lampu(bool red, bool yellow, bool green)
{
  digitalWrite(25, red);
  digitalWrite(26, yellow);
  digitalWrite(27, green);
}