https://www.upesy.com/blogs/tutorials/timer-esp32-with-micro-python-scripts#

from machine import Pin, Timer
from utime import sleep

print("Hello, ESP32!")


pin_led    = Pin(2, mode=Pin.OUT)
timer_0 = Timer(0) # Between 0-3 for ESP32

def interruption_handler(timer):
    pin_led.value(not pin_led.value())

if __name__ == "__main__":
    timer_0.init(mode=Timer.PERIODIC, period=200, callback=interruption_handler)

led = Pin(15, Pin.OUT)
while True:
  led.on()
  sleep(0.5)
  led.off()
  sleep(0.5)