MakeCode power extension programme does not go to sleep

[microbit-carlos]

Description

This programme does seem to go to sleep, neither in USB or battery. Although it's possible it goes to sleep but something wakes it up immediately.

Changing the [request low power] for a [request low power for [10000] ms] block does work.

Test Programme

input.onButtonPressed(Button.A, function () {
    basic.showString("A")
    power.lowPowerRequest()
})
basic.forever(function () {
    basic.showNumber(0)
    basic.showIcon(IconNames.Heart)
})

Hardware & Software

Tested on a V2.2 using the micro:bit power management extension and MakeCode live.

MakeCode info:

• makecode.microbit.org version: 5.0.6
• Microsoft MakeCode version: 8.0.3
• microbit runtime version: v2.2.0-rc6
• codal-microbit-v2 runtime version: v0.2.40

Extension:

• https://github.com/microbit-foundation/pxt-microbit-v2-power
• v0.2.3

Share link and hex:

• https://makecode.microbit.org/_eEL9T4CEearm
• microbit-Pwr-test-sleep.hex.zip

[JohnVidler]

Placing this in the v0.2.41 release for now, mainly to facilitate tracking it

[martinwork]

The power manager blocks low power mode if there are no wake up sources or if a timed wake up is due to trigger soon. A button handler does not automatically create a wake up source. See https://makecode.microbit.org/_Xwxhku8zqVUm. The forever loop has a pause because of https://github.com/lancaster-university/codal-microbit-v2/issues/201#issuecomment-1214165440

[microbit-carlos]

Thanks for the clarification Martin! So by adding the [full power on [button A]] block it then goes to sleep.

Was this done for a specific technical reason? In my opinion it should still go to sleep even if a wake up source wasn't configured, but there might be a reason why that's not preferable?

[martinwork]

In my opinion it should still go to sleep even if a wake up source wasn't configured

I guess we didn't think of a use for that. This controls whether sleep happens. https://github.com/lancaster-university/codal-microbit-v2/blob/master/source/MicroBitPowerManager.cpp#L708

It looks like the only technical consideration is if a time based wake up is about to trigger. In fact, I think it will always wake up when the USB is connected, and we didn't think we needed a control for that.

[JohnVidler]

I think this behaviour is now as expected as of 0.2.42, but I'm going to leave this open until I've confirmed this with a beta MakeCode build.

[microbit-carlos]

MakeCode test build with CODAL 0.2.42:

• https://makecode.microbit.org/app/7a9d7cf0337ed8d53fc507a899a5d414ee59a54d-9c844136fb
• https://github.com/microsoft/pxt-microbit/pull/4829

[microbit-carlos]

I think this behaviour is now as expected as of 0.2.42, but I'm going to leave this open until I've confirmed this with a beta MakeCode build.

I think the behaviour described in the original comments (not going to sleep unless a wake up source is configured) was by design in the extension? (which we might want to change)

Has something changed in CODAL to change this?

[microbit-carlos]

Testing this with the latest CODAL and it doesn't look like CODAL is going to sleep, so not something within the extension, but something to change in CODAL:

#include "MicroBit.h"

MicroBit uBit;

int main() {
    uBit.init();

    while (true) {
        uBit.power.deepSleep();
        uBit.display.print("A");
        uBit.sleep(500);
    }
}

MICROBIT.hex.zip

[martinwork]

See https://github.com/lancaster-university/codal-microbit-v2/blob/master/source/MicroBitPowerManager.cpp#L740

It's probably returning here https://github.com/lancaster-university/codal-microbit-v2/blob/master/source/MicroBitPowerManager.cpp#L773

[JohnVidler]

Done. Essentially removed the checks for going to a 'blind' deep sleep, and allow the board to do it. Furthermore, its now possible to wake the board with serial data from USB by default, so there should always be a wake source of some kind by default, even if the user never configures one (unless they manually disable wake-on-USB, of course)

[JohnVidler]

This is all now merged into master, pending being tagged - but I'll leave this open until we've built againts PXT and confirmed that this is solved... but I think this is now solved :)

[microbit-carlos]

Test URL for v0.2.43: https://makecode.microbit.org/app/37f6efa929bcadb89d3f5b689c0cf3cae27e49d1-df227f1388

[microbit-carlos]

@JohnVidler can you test this with the latest CODAL pxt test deployment?

[microbit-carlos]

This working in the latest CODAL/MakeCode.