from machine import Pin, Timer
import time
# objects to control GPIO pins
led1 = Pin(0, Pin.OUT)
led2 = Pin(1, Pin.OUT)
led3 = Pin(2, Pin.OUT)
# global variable to keep status of machine
status = 0
# object to control Timer
timer = Timer()
def state(X):
if X == 0:
led1.on(); led2.off(); led3.off()
elif X == 1:
led1.on(); led2.on(); led3.off()
elif X == 2:
led1.off(); led2.off(); led3.on()
elif X == 3:
led1.off(); led2.on(); led3.off()
def next_state(timer):
global status
state(status % 4)
status = status + 1
timer.init(freq=1, mode=Timer.PERIODIC, callback=next_state)