# 4 way traffic light using Micropython
from machine import Pin
from time import sleep

# Define the traffic lights pins
d_red = Pin(27, Pin.OUT)
d_yellow = Pin(26, Pin.OUT)
d_green = Pin(25, Pin.OUT)
r_red = Pin(21, Pin.OUT)
r_yellow = Pin(23, Pin.OUT)
r_green = Pin(22, Pin.OUT)
l_red = Pin(19, Pin.OUT)
l_yellow = Pin(17, Pin.OUT)
l_green = Pin(18, Pin.OUT)
u_red = Pin(16, Pin.OUT)
u_yellow = Pin(5, Pin.OUT)
u_green = Pin(4, Pin.OUT)

# Function to control a single traffic light
def change_lights():
    # Start (all yellow)
    u_red.off()
    d_red.off()
    r_red.off()
    l_green.off()
    u_yellow.on()
    d_yellow.on()
    r_yellow.on()
    l_yellow.on()
    sleep(5)

    # left lane go
    u_yellow.off()
    d_yellow.off()
    r_yellow.off()
    l_yellow.off()
    u_green.on()
    r_red.on()
    l_red.on()
    d_red.on()
    sleep(10)

    # All yellow
    u_yellow.on()
    d_yellow.on()
    r_yellow.on()
    l_yellow.on()
    u_green.off()
    r_red.off()
    l_red.off()
    d_red.off()
    sleep(5)

    # Right lane go
    u_yellow.off()
    d_yellow.off()
    r_yellow.off()
    l_yellow.off()
    u_red.on()
    l_red.on()
    d_red.on()
    r_green.on()
    sleep(10)

    # All yellow on
    u_yellow.on()
    d_yellow.on()
    r_yellow.on()
    l_yellow.on()
    u_red.off()
    l_red.off()
    d_red.off()
    r_green.off()
    sleep(5)

    # top lane go
    u_yellow.off()
    d_yellow.off()
    r_yellow.off()
    l_yellow.off()
    u_red.on()
    l_red.on()
    r_red.on()
    d_green.on()
    sleep(10)

    # All yellow
    u_yellow.on()
    d_yellow.on()
    r_yellow.on()
    l_yellow.on()
    u_red.off()
    l_red.off()
    r_red.off()
    d_green.off()
    sleep(5)

    # bottom lane go
    u_yellow.off()
    d_yellow.off()
    r_yellow.off()
    l_yellow.off()
    u_red.on()
    d_red.on()
    r_red.on()
    l_green.on()
    sleep(10)
while True:
    change_lights()