import time
import machine
import random
from machine import Pin, Timer

print(machine.freq() / 10000000)

led1 = Pin(1,Pin.OUT)
led2 = Pin(2,Pin.OUT)
led3 = Pin(3, Pin.OUT)

timer = Timer()

def blink_led(timer):
    while True:
        a = random.randint(0,100)

        if a>0 and a<25:
            led1.on()
            time.sleep(0.5)
            led1.off()
            time.sleep(0.5)

        if a > 25 and a < 75:
            led2.on()
            time.sleep(0.5)
            led2.off()
            time.sleep(0.5)
        else:
            led3.on()
            time.sleep(0.5)
            led3.off()
            time.sleep(0.5)


timer.init(freq = 2, mode = Timer.PERIODIC, callback = blink_led)
timer.sleep(20)
led1.off()
timer.deinit()