from machine import WDT, Pin, reset_cause, WDT_RESET
import time

led = Pin("LED", Pin.OUT)

# Create a watchdog with a 5-second timeout
wdt = WDT(timeout=5000)

print()
print("Watchdog Timer Demo")

if reset_cause() == WDT_RESET:
    print("*** Previous reset was caused by the WATCHDOG ***")
else:
    print("Normal startup")

start_time = time.ticks_ms()
last_blink = time.ticks_ms()

while True:

    elapsed = time.ticks_diff(time.ticks_ms(), start_time)

    # Simulate a lockup after 15 seconds
    if elapsed > 15000:
        print()
        print("*** Simulating software hang ***")
        print("*** Watchdog will reset the Pico in ~5 seconds ***")

        while True:
            pass

    # Feed watchdog during normal operation
    wdt.feed()

    # Blink LED once per second
    if time.ticks_diff(time.ticks_ms(), last_blink) >= 1000:
        last_blink = time.ticks_ms()

        led.toggle()

        print("Running:", elapsed // 1000, "seconds")

    time.sleep_ms(50)