Code size report:

   bare-arm:    +0 +0.000% 
minimal x86:    +0 +0.000% 
   unix x64:    +0 +0.000% standard
      stm32:    +0 +0.000% PYBV10
     mimxrt:    +0 +0.000% TEENSY40
        rp2:  +152 +0.017% RPI_PICO_W
       samd:    +0 +0.000% ADAFRUIT_ITSYBITSY_M4_EXPRESS
  qemu rv32:    +0 +0.000% VIRT_RV32

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.54%. Comparing base (f1018ee) to head (a0880ec).
Report is 202 commits behind head on master.

@@           Coverage Diff           @@
##           master   #16454   +/-   ##
=======================================
  Coverage   98.54%   98.54%           
=======================================
  Files         169      169           
  Lines       21877    21890   +13     
=======================================
+ Hits        21558    21572   +14     
+ Misses        319      318    -1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

Related PR #16431

Quick update for anyone wondering where all this has got to: This is the preferred fix for the rp2 lightsleep issues, but we can't merge it until raspberrypi/pico-sdk#2127 makes it into a pico-sdk release.

Thanks for the update projectgus. Any thoughts at all on when?
BTW There appears to be another behaviour which MAY not be covered by the current proposals/comments and it would be a pity if it escaped:
Pico 2 lightsleep(5000) ok, except when preceded by a sleep(nn). e.g. sleep(5)
This can be very confusing if encountered.
This does not happen on a Pico. I have not retested this recently on a PicoW or Pico2W because of their additional sleep problems.

I notice:
raspberrypi/pico-sdk#2127
Is not milestoned for 2.1.1 of the SDK (undated) but 2.2.0 (even further into the future I imagine and undated)
Is it anticipated that all the issues with sleeping will be cleared up by the fixes you plan such as #16454 and #16431?

We've updated to pico-sdk v2.1.1 in #16783, which includes the fix we're waiting on for the alarm pool.

@peterharperuk are you able to come back to this PR, or is it better if one of us picks it up from here?

Sorry, yes. I'll try and take a look this week.

@peterharperuk All good, we only just updated anyhow. Please let us know how you get on.

Thanks for all the work on this. Sorry if I am being dim but I am slightly confused because earlier on (above) it says "waiting for pico sdk 2127" but thats still milestoned for 2.2.0. Obviously it would be great if lightsleep is fixed before that. In case its useful as a baseline I reran my test program with 1.25.0 preview 389 and got 20 seconds for pico (correct), 15 seconds for pico2 (lightsleep after sleep returns early), 5 seconds picow and pico2w (lightsleep always returns early).

"waiting for pico sdk 2127" but thats still milestoned for 2.2.0.

Peter will know more than I do about this, but even though the milestone is set to 2.2.0 in their tracker the fix commit looks like it was included in the 2.1.1 tag: raspberrypi/pico-sdk@969f589

(The list of tags is on the line under the commit title in the GitHub UI.)

Please forgive me if I am wasting your time because of my lack of knowledge of github processes but I would be grateful if someone could answer a few questions:

On my copy of micropython I have done a "git pull" today, compiled micropython (I struggled slightly with picotool but fixed that) and I get a 1.25.0 preview 442 for the 4 types of pico. On the download page the newest version for everything I have looked at is for example: https://micropython.org/resources/firmware/RPI_PICO2-20250327-v1.25.0-preview.428.g50da085d9.uf2 which is dated 27/03/25.
Q: Has the automated build process broken?

I notice that #16454 is milestoned for 1.26.0 (undated) and that 1.25.0 has progressed very rapidly since I last looked (although described as overdue by 3 months) but it doesn't seem to have 16454 included as far as I can tell.
Q: Does anyone have a date when the downloadable automatic development build will have the 16454 fix?

For info:
I ran my test program today with the 442 build I generated. I found no change from the behaviour of 1.24.1.
On Pico2:
lightsleep returns very quickly if preceded by a time.sleep, but other things correct, current fractionally over 3ma.

On the pico_w and pico2_w
lightsleep returns very quickly, unless using safe_sleep (lightsleep in a loop checking that the correct total time has been slept for)
With wireless disabled current approx 4.6ma using safe_sleep.

Q: is this the behaviour I should expect with the 442 build?

Q: do any of the lightsleep PRs currently being considered fix the "lightsleep preceded by time.sleep" issue?

I have just had a thought when writing this and will test it tomorrow. Say I want:
time.sleep_ms(750)
....... (some code)
lightsleep(5000)

would the lightsleep(5000) work properly if I did:
time.sleep_ms(750)
....... (some code)
lightsleep(1) # some value that fails, or provides a known short delay
lightsleep(5000)

If there is a known short delay it could be subtracted form 5000 to give the correct overall delay

Good news, the extra lightsleep trick works! I put an extra lightsleep(5000) in and it came back from from that very quickly and the second lightsleep(5000) worked. I can recalibrate the timing and get on with the projects I have now that I have a workaround for both bugs. I feel a bit silly I didnt think of that before!

I notice:

https://micropython.org/resources/firmware/RPI_PICO2-20250407-v1.25.0-preview.447.g9e9be83fd.uf2

has now appeared, I will test again tomorrow..

I notice:

https://micropython.org/resources/firmware/RPI_PICO2-20250407-v1.25.0-preview.447.g9e9be83fd.uf2

has now appeared, I will test again tomorrow..

This nightly build is available, but the nightly builds only contain changes which have been merged to the "master" branch. While a PR is in the Open state, this hasn't happened yet so these changes are not included in that build.

If you want to test these changes then you have to check out this exact PR's code and compile with it. There are multiple ways to do this, including GitHub Desktop (I believe). The way I do it is to install the GitHub CLI tool (separate to git) and use the gh pr checkout command.

Thanks for your time, clarification, and the info on the gh command, projectgus. I will try that later.

That leaves me with 2 remaining questions from earlier:

I notice that #16454 is milestoned for 1.26.0 (undated) and that 1.25.0 has progressed very rapidly since I last looked (although described as overdue by 3 months) but it doesn't seem to have 16454 included as far as I can tell.
Q: Does anyone have an estimated date when the downloadable automatic development build will have the 16454 fix?

Q: Do any of the several lightsleep PRs currently being considered fix the "lightsleep preceded by time.sleep" issue?

Projectgus,
In case it might be useful I tried the "gh pr checkout 16454" on my clone and it built to a uf2, seemingly without problems. On trying it on a Pico2, it appeared to fix the "lightsleep after sleep" problem.
I then produced a uf2 for the Pico2_W but that still suffers from the early return problem. I cant tell if it has the "lightsleep after sleep" problem, obviously. I have not experimented with turning off the wireless 1st, yet.

Pico2_W but that still suffers from the early return problem

Timers firing in LwIP?

Probably the Firing in LwIP thing, if I have understood properly. if there is a PR at a state that's worth testing I am willing to give it a go.

Probably the Firing in LwIP thing, if I have understood properly. if there is a PR at a state that's worth testing I am willing to give it a go.

No PR for this yet, follow issue #16181 for that one.

I also cherry-picked the unit test I added for lightsleep on CPU1 and pushed it here. It passes. I think could either add it to this PR, or I'll submit it as a follow-up.

Would be good to add this test to this PR. Angus will look into that.

Would be good to add this test to this PR. Angus will look into that.

Pushed!

@projectgus I tested your new test on a RPI_PICO2_W, and it fails. The third test fails:

$ mpremote run tests/ports/rp2/rp2_lightsleep_thread.py
test_cpu0_busy (__main__.LightSleepInThread) ... ok
test_cpu0_sleeping (__main__.LightSleepInThread) ... ok
test_cpu0_also_lightsleep (__main__.LightSleepInThread) ... FAIL

======================================================================
FAIL: test_cpu0_also_lightsleep <class 'LightSleepInThread'>
----------------------------------------------------------------------
Traceback (most recent call last):
  File "unittest/__init__.py", line 399, in run_one
  File "<stdin>", line 56, in test_cpu0_also_lightsleep
  File "unittest/__init__.py", line 133, in assertAlmostEqual
AssertionError: 254 != 2500 within 1250 delta

----------------------------------------------------------------------
Ran 3 tests

FAILED (failures=1, errors=0)

Can you reproduce that failure?

Maybe we can just merge this PR without your test, and investigate your test failure as a follow up?

Can you reproduce that failure?

I can't, I just ran the test 15 times in a loop on RPI_PICO2_W and it passes every time. That's with the commit in this branch (a0880ec), I haven't rebased it against master.

Any chance your board might have a boot.py or something on it that's causing some subtle change?

The plot thickens:

• Building this PR as-is without rebasing it on master, the new test can pass. BUT, it prints "F2 not ready" as part of the 3rd unittest, which means the cyw43 is having issues starting up (and that's due to the use of the LED in the test).
• Making sure network.WLAN().active(1) is run before the tests, and the "F2 not ready" message goes away and the test passes.
• Building this PR rebased on master, the new test consistently fails, even if WLAN is activated before running the test.

My initial comment below was flawed by a code typo. I have removed the affected error report.

FWIW I have been using the "safe_sleep" code below to work around the "lightsleep returns early" problem on Pico W and 2w, when I test with:
MicroPython v1.26.0-preview.51.g00a0cd70f on 2025-05-01; Raspberry Pi Pico 2 W with RP2350

Iin cases its news, the "Lightsleep returns early" still happens on Pico2 W (haven't tried Pico W).
2350 based devices still have the "time.time does not advance", and "time.time forces lightsleep early return" on Pico2 with its preview 51

Safe_sleep(5000)

def safe_sleep(ms: int):
    begin = time.ticks_ms()
    wake = -1
    sleep = ms
    while sleep > 0:
        safe_sleep(sleep) Edit: my mistake will retest with lightsleep(sleep) tomorrow
        wake += 1
        sleep = ms - time.ticks_diff(time.ticks_ms(), begin)
    return

@ssotheremail: Replace the line
safe_sleep(sleep)
with
machine.lightsleep(sleep)
and you should be fine. Your code actually never sleeps, but calls itself 5000 times.

idiot me, I was in a rush and did a global edit in another file replacing lightsleep with safe_sleep, then cut and pasted the def safe_sleep here.... Oh dear. I will retest tomorrow.