[Bug] city hub re-powers ON after button-keep to power-off on github hash 191b715d and older

[BertLindeman]

Sorry for the long post, but I want to be complete. . .

Describe the bug
cityhub at `ci-build-3813-v3.6.1-152-g191b715d' after power-off (with the hub button) the hub restarts

Have NOT noticed this on movehub, Technichub, primehub nor Robot Inventor hub at the same firmware.

Tested a number of firmwares for the cityhub.
Not all of them from the master branch.
The oldest I tried was cityhub-firmware-build-3776-git91d7221e
Same result.

To be sure it is no hardware thing I flashed the current beta.
No problem at that firmware - ci-release-86-v3.6.1 on 2025-03-11

To reproduce 1
Steps to reproduce the behavior:

1. Put the hub on
2. connect to a pc
3. disconnect (using the pc button)
4. press and keep the hub button until the hub flashes fast and goes off
5. See the error: after less than a second hub restarts

To reproduce 2
Steps to reproduce the behavior:

1. Put the hub on
2. connect to a pc
3. run this:

from pybricks.hubs import ThisHub
hub = ThisHub()
hub.system.shutdown()

4. hub goes off
5. hub restarts.

Scenario difference between hash 0663e76d and hash da108b30
This scenario does not restart on github hash 0663e76d.
But does restart at github hash da108b30:

1. pull the batteries from the hub and reinsert
2. press the hub button
3. hub starts
4. press and keep the hub button until the hub flashes and goes off
   And no restart on github hash 0663e76d
   But a restart on github hash da108b30

Another no restart scenario:

1. connect to the hub
2. enter the REPL
3. issue the command hub.system.shutdown()
4. hub goes off and stays off

Expected behavior
Hub should stay off

Screenshots
There is a saying that a picture is worth a 1000 words. Screenshots really help to identify and solve problems.

[zus2]

Can only be a hub firmware call to reboot? Do not know how these flags work are set or stored , but are used when you install / upgrade computers OSs to reboot etc.

…

On 30 Apr 2025, at 22:38, Bert ***@***.***> wrote: BertLindeman created an issue (pybricks/support#2176) <#2176> Sorry for the long post, but I want to be complete. . . Describe the bug cityhub at `ci-build-3813-v3.6.1-152-g191b715d' after power-off (with the hub button) the hub restarts Have NOT noticed this on movehub, Technichub, primehub nor Robot Inventor hub at the same firmware. Tested a number of firmwares for the cityhub. Not all of them from the master branch. The oldest I tried was cityhub-firmware-build-3776-git91d7221e Same result. To be sure it is no hardware thing I flashed the current beta. No problem at that firmware - ci-release-86-v3.6.1 on 2025-03-11 To reproduce 1 Steps to reproduce the behavior: Put the hub on connect to a pc disconnect (using the pc button) press and keep the hub button until the hub flashes fast and goes off See the error: after less than a second hub restarts To reproduce 2 Steps to reproduce the behavior: Put the hub on connect to a pc run this: from pybricks.hubs import ThisHub hub = ThisHub() hub.system.shutdown() hub goes off hub restarts. Scenario difference between hash 0663e76d and hash da108b30 This scenario does not restart on github hash 0663e76d. But does restart at github hash da108b30: pull the batteries from the hub and reinsert press the hub button hub starts press and keep the hub button until the hub flashes and goes off And no restart on github hash 0663e76d But a restart on github hash da108b30 Another no restart scenario: connect to the hub enter the REPL issue the command hub.system.shutdown() hub goes off and stays off Expected behavior Hub should stay off Screenshots There is a saying that a picture is worth a 1000 words. Screenshots really help to identify and solve problems. — Reply to this email directly, view it on GitHub <#2176>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AKHCFE6YBODY47OMURZZ5JL24EYGBAVCNFSM6AAAAAB4GSPTIGVHI2DSMVQWIX3LMV43ASLTON2WKOZTGAZTENBVHAYTGNQ>. You are receiving this because you are subscribed to this thread.

[dlech]

This is a bug we have fixed several time already. 😄 #692 #385

Sounds like we've managed to regress it again.

[laurensvalk]

Sorry about that. There have been extensive changes to this part of the code lately. Admittedly, it hasn't been tested much on City Hub. Fortunately @BertLindeman is here to help us, and keep us on our toes. 😄

[BertLindeman]

Trying to be complete (hum)

No devices attached to cityhub.
Battery: Voltage: 7599

[BertLindeman]

Similar situation seen at Commit 0f065bb

Not verified at what exact commit this started again.
This was the last commit applied to master for PR 387

Scenario 2 does NOT trigger the re-power on.

Scenario 2 run shutdown program:

from pybricks.hubs import ThisHub
hub = ThisHub()
hub.system.shutdown()

Correctly powers-off and does not automatically re-powers-ON.

[laurensvalk]

I cannot reproduce this. There may be some variations between the hub.

hub.system.shutdown() (...) Correctly powers-off and does not automatically re-powers-ON.

But this gives me an idea... We could delay power off until after the user releases the button, and add some margin.

Then power-off will be the same in all scenarios, which should work in your case.

[laurensvalk]

Bert, would you be able to test if:

• It still occurs at cityhub-firmware-build-4192-git0f065bbd that you tested before: https://github.com/pybricks/pybricks-micropython/actions/runs/17938798572. Just to confirm your previous result.
• And if it still happens with this patch https://github.com/pybricks/pybricks-micropython/actions/runs/18279420999 ?

Thanks!