import time
from machine import Pin, ADC

led = Pin(2, Pin.OUT)
adc = ADC(Pin(34))
adc.atten(ADC.ATTN_11DB)  # Allow full 0-3.3V ADC range

LED_INTERVAL   = 500    # ms
ADC_INTERVAL   = 1000   # ms
PRINT_INTERVAL = 2000   # ms

last_led   = time.ticks_ms()
last_adc   = time.ticks_ms()
last_print = time.ticks_ms()
adc_value  = 0

while True:
    now = time.ticks_ms()

    # Task 1 — toggle LED every 500 ms
    if time.ticks_diff(now, last_led) >= LED_INTERVAL:
        led.value(not led.value())
        last_led = now

    # Task 2 — read ADC every 1000 ms
    if time.ticks_diff(now, last_adc) >= ADC_INTERVAL:
        adc_value = adc.read()
        last_adc = now

    # Task 3 — print every 2000 ms
    if time.ticks_diff(now, last_print) >= PRINT_INTERVAL:
        print('ADC reading:', adc_value)
        last_print = now