brickcontroller2 | No script push while phone screen is off

[SegasAtreides]

Script push from phone/BC2 app to MK 6.0 hub stops once the phone screen is locked/switched off. This happens even with the app having full phone permissions.
Device details: S23 Ultra, Android ver.16, ONE UI version 8.5.

[J0EK3R]

Here is Copilot's answer:

Here’s a clean, issue‑ready English answer you can paste directly into the GitHub thread.
It explains the root cause, why it’s Samsung‑specific, and what the user must change.

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Proposed GitHub Issue Reply (English)

The behavior is not caused by BrickController2. On Samsung devices running Android 16 / One UI 8.5 (including the S23 Ultra), background BLE operations are aggressively restricted as soon as the screen turns off. When this happens, the OS throttles or suspends the BC2 process, which interrupts the script push to the MK 6.0 hub.

BC2 uses a continuous BLE write loop during script upload. Samsung’s background‑process policies stop this loop when the phone enters Doze/App Standby/Deep Sleep, even if all permissions are granted.

To keep the script push running with the screen locked, the following Samsung‑specific settings must be changed:

1. Battery → Background usage → Set BrickController2 to “Unrestricted”
2. Battery → App power management → Disable “Auto manage” / “Put unused apps to sleep”
3. Battery → Adaptive battery → Turn off
4. Apps → BrickController2 → Battery → Allow background activity
5. Lock screen → Allow apps to run when the screen is locked
   (Name varies by region: “Keep app running”, “Don’t pause app”, etc.)
6. Developer options → Disable Bluetooth scan throttling

If the script push still stops after applying all settings, add BC2 to:

Battery → Background usage → “Never sleeping apps” / “Not monitored apps”

This prevents One UI from ever putting the app into Deep Sleep.

In short: Samsung’s background restrictions are terminating BLE operations when the screen is off. Adjusting the above settings ensures BC2 can maintain the BLE connection and complete the script upload.

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[SegasAtreides]

Thanks for the suggestions. I performed some additional testing on my Samsung S23 Ultra (Android 16 / One UI 8.5).

Unfortunately, disabling Battery Optimization and Adaptive Battery did not change the behavior.

More interestingly, I observed the following:

When the phone screen is ON, BrickController Legacy controls the MK 6.0 hub normally.
When the screen turns OFF, the MK 6.0 hub immediately stops responding.
As soon as I unlock the phone, control resumes immediately without reconnecting the hub.
While the screen is OFF, the wireless controller is still active. Pressing buttons on the controller wakes the phone, which indicates Android is still receiving HID input from the controller.

This makes me think the controller connection itself is not the issue.

My current hypothesis is that the BLE command transmission loop is being paused when the app is no longer in the foreground, rather than the controller disconnecting or Android's battery optimization terminating the Bluetooth connection.

Has anyone confirmed whether BrickController Legacy keeps sending BLE motor commands while the Activity is paused or the screen is locked? Or is the BLE write loop tied to the foreground Activity?

[vicocz]

In general, it's by design at the moment. BC2 app stop the play loop and disconnects all devices if the app falls asleep as it's not the background running app (e.g. user switch off the screen manually). Similarly if you turn screen ON for Play page, it tries to reconnect.

Also e.g. on Android, if you switch the screen OFF, BLE device might get disconnected after some timeout I guess.

So from MK perspective:

• if you turn the screen OFF, BC2 calls disconnect command for a MK device
• once you turned it ON, it should try to reconnect

Based on that it seems to me this issue must be related to Disconnect / Connect calls of BluetoothAdvertisingDevice as it works for standard BLE devices such as e.g. BuWizz.

[J0EK3R]

The current behavior of BC2 with BluetoothAdvertisingDevice on my smartphone is as follows:

• App in the foreground
  → Everything works correctly.

• App in the background / smartphone screen off
  → No Bluetooth advertisements are sent immediately (no disconnect commands exist).
  → The MK6 stops all outputs after its timeout (about 2 seconds) because no datagrams were received.

• App returns to the foreground / smartphone screen on
  → Connect datagrams are sent to the MK6 again until you change an input channel (when you interact with your game controller).

The (return to foreground) behavior is as designed.