from machine import Pin
from time import sleep

red=Pin(15,Pin.OUT)
blue=Pin(16,Pin.OUT)
yellow=Pin(17,Pin.OUT)
green=Pin(18,Pin.OUT)
blue_btn=Pin(12,Pin.IN,Pin.PULL_DOWN)
yellow_btn=Pin(14,Pin.IN,Pin.PULL_DOWN)

counter = 0

green.on()
red.off()

while True:
    
    if yellow_btn.value() == 1:
        if counter < 15:
            counter = counter + 1
            print("Car entered. Count:", counter)
            
            
            yellow.on()
            sleep(0.2)
            yellow.off()
            
            if counter == 15:
                green.off()
                red.on()
                
            sleep(0.3) 
            
    
    if blue_btn.value() == 1:
        if counter > 0:
            counter = counter - 1
            print("Car exited. Count:", counter)
            
            blue.on()
            sleep(0.2)
            blue.off()
            
            if counter < 15:
                green.on()
                red.off()
                
            sleep(0.3)