RP2350 the watchdog timer does not count down while lightsleep is running
Port, board and/or hardware
Raspberry Pi Pico2
MicroPython version
MicroPython v1.25.0 on 2025-04-15; Raspberry Pi Pico2 with RP2350
Reproduction
Copy the following into wdt_lightsleep_2350.py.
from machine import lightsleep, WDT
from time import sleep_ms
wdt = WDT(timeout=5000)
lightsleep(3000)
sleep_ms(3000)
print('Should not print')
sleep_ms(3000)
Do 'mpremote run wdt_lightsleep_2350.py'.
Expected behaviour
Expect the same behavior seen when the lightsleep is replaced with sleep_ms.
File wdt_sleep_ms_2350.py
from machine import lightsleep, WDT
from time import sleep_ms
wdt = WDT(timeout=5000)
sleep_ms(3000)
sleep_ms(3000)
print('Should not print')
sleep_ms(3000)
>> mpremote run wdt_sleep_ms_2350.py
Traceback (most recent call last):
File "/home/picompute/.local/bin/mpremote", line 8, in <module>
sys.exit(main())
Note: most of traceback removed.
This time the print did not execute because the watchdog timer triggered during the second sleep_ms(3000).
Observed behaviour
The print statement does execute and the watchdog timer triggers during the last sleep_ms(3000).
>> mpremote run wdt_lightsleep_2350.py
Should not print
Traceback (most recent call last):
File "/home/picompute/.local/bin/mpremote", line 8, in <module>
sys.exit(main())
Note: most of traceback removed.
Additional Information
I have changes to lightsleep in modmachine.c which fix this problem.
I will prepare a pull request with this fix.
The root cause is the watchdog timer does not count down while lightsleep() is running.
This problem is RP2350 specific and is not seen on RP2040.
Code of Conduct
Yes, I agree
RP2350 / Pico 2 machine.lightsleep not working correctly
Port, board and/or hardware
Pico 2 / RP2350
MicroPython version
MicroPython v1.24.0-preview.201.g269a0e0e1 on 2024-08-09; Raspberry Pi Pico2 with RP2350
Reproduction
- Install latest Firmware from https://micropython.org/download/RPI_PICO2/
- Implement
machine.lightsleep(5000)in your code - Run code.
Expected behaviour
Expected Pico 2 to enter lightsleep mode for 5 seconds, then continue to next bit of code.
Observed behaviour
lightsleep is maybe entered for a cycle or so, but code carries on and never stops executing for any time value I enter for lightsleep.
Additional Information
Complete code example:
# Lightsleep MicroPython example.
from machine import Pin
import time
led = Pin(25, Pin.OUT)
while True:
led.toggle()
time.sleep_ms(5000)
led.toggle()
machine.lightsleep(5000)
Code of Conduct
Yes, I agree