traffic_signal

traffic_signal.ino

#define PIN_GREEN 0
#define PIN_YELLOW 4
#define PIN_RED 2
#define PIN_GND 1

void setup() {
  // put your setup code here, to run once:
  pinMode(PIN_GREEN, OUTPUT);
  pinMode(PIN_GND, OUTPUT);
  pinMode(PIN_YELLOW, OUTPUT);
  pinMode(PIN_RED, OUTPUT);
  analogWrite(PIN_GND, 100);
  digitalWrite(PIN_YELLOW, LOW);
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(PIN_RED, LOW);
  digitalWrite(PIN_GREEN, HIGH);
  delay(20000);
  digitalWrite(PIN_GREEN, LOW);
  digitalWrite(PIN_YELLOW, HIGH);
  delay(3000);
  digitalWrite(PIN_YELLOW, LOW);
  digitalWrite(PIN_RED, HIGH);
  delay(15000);
}