// Define pins for each road
// Define pins for each road
#define R1 0
#define Y1 1
#define G1 2

#define R2 28
#define Y2 27
#define G2 26

#define R3 22
#define Y3 21
#define G3 20

#define R4 13
#define Y4 14
#define G4 15

void setup() {
  // Set all pins as output
  pinMode(R1, OUTPUT); pinMode(Y1, OUTPUT); pinMode(G1, OUTPUT);
  pinMode(R2, OUTPUT); pinMode(Y2, OUTPUT); pinMode(G2, OUTPUT);
  pinMode(R3, OUTPUT); pinMode(Y3, OUTPUT); pinMode(G3, OUTPUT);
  pinMode(R4, OUTPUT); pinMode(Y4, OUTPUT); pinMode(G4, OUTPUT);

  // Start with all Red ON
  digitalWrite(R1, HIGH);
  digitalWrite(R2, HIGH);
  digitalWrite(R3, HIGH);
  digitalWrite(R4, HIGH);
}

// Helper function for one road cycle
void roadCycle(int R, int Y, int G) {
  // All roads Red
  digitalWrite(R1, HIGH);
  digitalWrite(R2, HIGH);
  digitalWrite(R3, HIGH);
  digitalWrite(R4, HIGH);

  // Allow this road
  digitalWrite(R, LOW);   // Red OFF
  digitalWrite(G, HIGH);  // Green ON
  delay(3000);

  digitalWrite(G, LOW);
  digitalWrite(Y, HIGH);  // Yellow ON
  delay(1000);

  digitalWrite(Y, LOW);
  digitalWrite(R, HIGH);  // Back to Red
}

void loop() {
  roadCycle(R1, Y1, G1);
  roadCycle(R2, Y2, G2);
  roadCycle(R3, Y3, G3);
  roadCycle(R4, Y4, G4);
}

/*from machine import Pin
import time

//# Define pins for each road
R1 = Pin(0, Pin.OUT)
Y1 = Pin(1, Pin.OUT)
G1 = Pin(2, Pin.OUT)

R2 = Pin(28, Pin.OUT)
Y2 = Pin(27, Pin.OUT)
G2 = Pin(26, Pin.OUT)

R3 = Pin(22, Pin.OUT)
Y3 = Pin(21, Pin.OUT)
G3 = Pin(20, Pin.OUT)

R4 = Pin(13, Pin.OUT)
Y4 = Pin(14, Pin.OUT)
G4 = Pin(15, Pin.OUT)

//# Start with all Red ON
R1.value(1)
R2.value(1)
R3.value(1)
R4.value(1)

def road_cycle(R, Y, G, delay_green=3, delay_yellow=1):
    //# Turn all roads Red
    R1.value(1); R2.value(1); R3.value(1); R4.value(1)
    //# Allow this road
    R.value(0)
    G.value(1)
    time.sleep(delay_green)

    G.value(0)
    Y.value(1)
    time.sleep(delay_yellow)
    Y.value(0)
    R.value(1)

//# Main loop
while True:
    road_cycle(R1, Y1, G1)
    road_cycle(R2, Y2, G2)
    road_cycle(R3, Y3, G3)
    road_cycle(R4, Y4, G4)*/