QUERY · ISSUE

RP2: machine.RTC().datetime() does not advance during lightsleep

openby madozuopened 2025-01-03updated 2025-12-13

bugport-rp2

Port, board and/or hardware

Raspberry Pi Pico W and Raspberry Pi Pico 2 W

MicroPython version

All versions starting with v1.24.0 (including recently released v1.26.0)

Reproduction

Copy code below to Pico and name it "main.py"
Reset the Pico and allow the code to complete (approx 5 seconds). No repl needed as the code writes a log file to the flash storage
Connect the Pico to the USB port and inspect the file "local.log" on the Pico

Code used to test:

# Test RTC sleep behaviour
import machine, os, time

SLEEP_MS = const(2000)

def write_log(s: str) -> None:
    dt = machine.RTC().datetime()
    log_text = f"[RTC={dt[4]:02d}:{dt[5]:02d}:{dt[6]:02d} ticks={time.ticks_ms()}]  {s}"
    with open("local.log", "a") as file:
        file.write(log_text + "\n")

write_log(f"Machine = '{os.uname()[4]}'")
write_log(f"Version = '{os.uname()[3]}'")
time.sleep_ms(SLEEP_MS)
write_log(f"After time.sleep_ms({SLEEP_MS})")
machine.lightsleep(SLEEP_MS)
write_log(f"After machine.lightsleep({SLEEP_MS})")

Expected behaviour

The real time clock should advance by 2 seconds after running 'machine.lightsleep(2000)' like it was on micropython versions up to and including 1.23.0. Example output from 1.23.0:

[RTC=00:00:01 ticks=49]  Machine = 'Raspberry Pi Pico W with RP2040'
[RTC=00:00:01 ticks=54]  Version = 'v1.23.0 on 2024-06-02 (GNU 13.2.0 MinSizeRel)'
[RTC=00:00:03 ticks=2058]  After time.sleep_ms(2000)
[RTC=00:00:05 ticks=4065]  After safe_sleep(2000) with 0 early wakeups

Observed behaviour

The real time clock does not advance during machine.lightsleep(2000) as shown below running on 1.26.0:

[RTC=00:00:01 ticks=36]  Machine = 'Raspberry Pi Pico W with RP2040'
[RTC=00:00:01 ticks=42]  Version = 'v1.26.0 on 2025-08-09 (GNU 14.2.0 MinSizeRel)'
[RTC=00:00:03 ticks=2033]  After time.sleep_ms(2000)
[RTC=00:00:03 ticks=4037]  After machine.lightsleep(2000)

Additional Information

While machine.RTC().datetime() does not advance during machine.lightsleep(), time.ticks_ms advances as expected.

Code of Conduct

Yes, I agree

CANDIDATE · ISSUE

machine.RTC.datetime broken on Raspberry Pi Pico

closedby evilhamstermanopened 2022-10-18updated 2022-10-18

bug

Disregarding all the other issues with the RTC library in MicroPython, it appears it is completely broken in the current version on Raspberry Pi Pico. Whenever trying to set the time using machine.RTC.datetime passing a tuple returns an error that argument is the wrong type, same thing with a list. And calling the function without an argument says its missing 1 required argument instead of returning a tuple.

MPY: soft reboot
MicroPython v1.19.1 on 2022-10-14; Raspberry Pi Pico with RP2040
Type "help()" for more information.
>>> import machine
>>> rtc=machine.RTC.datetime((2022,10,17,0,21,33,0,0))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: argument has wrong type
>>> rtc=machine.RTC
>>> rtc.datetime((2022,10,17,0,21,33,0,0))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: argument has wrong type
>>> rtc.datetime()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: function missing 1 required positional arguments
>>>