feats: prevent sleep while active BT profile connected and allow sleep while USB power connected by newx-it · Pull Request #3288 · zmkfirmware/zmk

newx-it · 2026-03-19T14:41:28Z

I'm closing my previous PR in favor of this one, which has some fixes applied and should have proper commit messages/clean commit history.

In short, I've added two flags:
CONFIG_ZMK_BLE_PREVENT_SLEEP_WHILE_ACTIVE_CONNECTED and CONFIG_ZMK_USB_ALLOW_SLEEP_WHILE_POWERED
The first allows the user to disable sleeping when the active BT profile is connected, related to issue 2198. The second arose naturally as I was testing my work on the first, but I believe it has merit as a means of increasing battery life for peripherals on devices that have the "main" device plugged in, whether it be a dongle or just a split.

pre-commit doesn't seem to like my formatting but I believe it's getting confused by the broken up lines, which are added for readability.

Like with my last PR, I am a new contributor (and new to open source as a whole) so any and all advice is appreciated!

PR check-list

Branch has a clean commit history
Additional tests are included, if changing behaviors/core code that is testable.
Proper Copyright + License headers added to applicable files (Generally, we stick to "The ZMK Contributors" for copyrights to help avoid churn when files get edited)
Pre-commit used to check formatting of files, commit messages, etc.
Includes any necessary documentation changes.

Adds a flag which, when enabled, allows users to prevent the device from sleeping when the chosen BT profile is connected/active.

Adds a flag which allows users to enable sleep even if USB power is present.

fixed an error caused by an extra line of code that wasn't deleted

Not sure why pre-commit is having issues with the changes in activity.c, but attempted a fix there and fixed the final formatting issue in power.md

Removed stray backslash character

caksoylar

Implementation looks OK to me, but it is worth noting that the timeout does not reset while BLE is connected. So the part can immediately go to sleep once it disconnects, if it has been idle for a while. I think that's fine, but might be worth noting somewhere in the docs.

Also, pre-commit is failing and needs to be fixed. You can set it up locally to fix things for you when you push: https://zmk.dev/docs/development/local-toolchain/pre-commit

caksoylar · 2026-03-22T04:22:08Z

    int "Milliseconds of inactivity before entering deep sleep"
    default 900000

+config ZMK_BLE_PREVENT_SLEEP_WHILE_ACTIVE_CONNECTED


IMO these should be prefixed with ZMK_SLEEP, since they are all sub-options related to it.

Suggested change

config ZMK_BLE_PREVENT_SLEEP_WHILE_ACTIVE_CONNECTED

config ZMK_SLEEP_PREVENT_WHILE_BLE_CONNECTED

caksoylar · 2026-03-22T04:22:28Z

+    depends on ZMK_BLE
+    default n
+
+config ZMK_USB_ALLOW_SLEEP_WHILE_POWERED


Suggested change

config ZMK_USB_ALLOW_SLEEP_WHILE_POWERED

config ZMK_SLEEP_PREVENT_WHILE_USB_POWERED

Renamed both config flags, slightly changed syntax to support the swap from "allow" to "prevent" for the USB power flag.

fix formatting according to pre-commit's preferences

newx-it · 2026-03-24T03:04:19Z

Pushed a couple changes but I'm having trouble phrasing the doc changes for the lack of BLE timeout. any suggestions?

Added documentation for the interaction between BT connection keeping the device awake and the sleep timer. When the device loses connection after the sleep timer has elapsed, it will immediately sleep.

newx-it · 2026-03-24T05:57:24Z

Alright, docs should be fixed. I'm conflicted about whether I should just reset the timer for a more intuitive sleep timer instead though, or even add a third flag to allow either behavior. Any opinions?

caksoylar

I think this behavior is fine; I wouldn't overcomplicate it with more options.

Also please check the failed pre-commit again -- running prettier after editing the tables as below should fix it.

caksoylar · 2026-03-29T20:28:33Z

+| `CONFIG_ZMK_SLEEP`                                    | bool | Enable deep sleep support                                                                                                                  | n       |
+| `CONFIG_ZMK_IDLE_SLEEP_TIMEOUT`                       | int  | Milliseconds of inactivity before entering deep sleep                                                                                      | 900000  |
+| `CONFIG_ZMK_PM_SOFT_OFF`                              | bool | Enable soft off functionality from the keymap or dedicated hardware                                                                        | n       |
+| `CONFIG_ZMK_BLE_PREVENT_SLEEP_WHILE_ACTIVE_CONNECTED` | bool | Prevent sleeping while the active BT profile is connected. If the device loses connection after the sleep timer, it will sleep immediately | n       |


Suggested change

| `CONFIG_ZMK_BLE_PREVENT_SLEEP_WHILE_ACTIVE_CONNECTED` | bool | Prevent sleeping while the active BT profile is connected. If the device loses connection after the sleep timer, it will sleep immediately | n |

| `CONFIG_ZMK_SLEEP_PREVENT_WHILE_BLE_CONNECTED` | bool | Prevent sleeping while the active BT profile is connected. If the device loses connection after the sleep timer, it will sleep immediately | n |

mismatching the Kconfig file; also will need a prettier pass to fix table formatting

caksoylar · 2026-03-29T20:28:46Z

+| `CONFIG_ZMK_IDLE_SLEEP_TIMEOUT`                       | int  | Milliseconds of inactivity before entering deep sleep                                                                                      | 900000  |
+| `CONFIG_ZMK_PM_SOFT_OFF`                              | bool | Enable soft off functionality from the keymap or dedicated hardware                                                                        | n       |
+| `CONFIG_ZMK_BLE_PREVENT_SLEEP_WHILE_ACTIVE_CONNECTED` | bool | Prevent sleeping while the active BT profile is connected. If the device loses connection after the sleep timer, it will sleep immediately | n       |
+| `CONFIG_ZMK_USB_PREVENT_SLEEP_WHILE_POWERED`          | bool | Prevent sleeping while USB power is connected                                                                                              | y       |


renamed flag names in docs to match previous changes

caksoylar · 2026-03-29T23:24:48Z

+config ZMK_SLEEP_PREVENT_WHILE_BLE_CONNECTED
+    bool "Prevent sleeping while the active BT profile is connected"
+    depends on ZMK_BLE
+    default n


One thing I missed; can you remove? See #2161

Suggested change

default n

removed the redundante Kconfig "default n" value from the ZMK_SLEEP_PREVENT_WHILE_BLE_CONNECTED flag

caksoylar

Thanks!

veypatch · 2026-04-03T21:51:06Z

Been using this for a couple days now. Amazing feature and works great! Quite huge battery savings as well as the keyboard won't stay in "search" mode when the computer has already been turned off and waiting for the sleep timeout.

@jkosh44

) Adds CONFIG_ZMK_SLEEP_PREVENT_WHILE_BLE_CONNECTED to prevent deep sleep while the active BT profile is connected. Avoids Issue zmkfirmware#3207 (Central fails to wake from deep sleep). Based on zmkfirmware#3288 by @jkosh44

newx-it added 4 commits March 19, 2026 08:18

feat(ble): prevent sleep while BT is active

8b4bf7d

Adds a flag which, when enabled, allows users to prevent the device from sleeping when the chosen BT profile is connected/active.

feat(usb): allow sleeping while powered over USB

2d77d1d

Adds a flag which allows users to enable sleep even if USB power is present.

fix: formatting

ba812cb

fix: formatting

f3d9aaa

newx-it requested review from a team as code owners March 19, 2026 14:41

This was referenced Mar 19, 2026

Feat: BLE prevent sleep while active connected and Feat: allow sleep while USB powered #3286

Closed

[Feature Request] Option to disable sleep while bluetooth connection is active #2198

Open

newx-it and others added 3 commits March 19, 2026 08:49

fix: syntax error

fd67eb2

fixed an error caused by an extra line of code that wasn't deleted

fix: more formatting

0511b3a

Not sure why pre-commit is having issues with the changes in activity.c, but attempted a fix there and fixed the final formatting issue in power.md

fix: syntax

7469360

Removed stray backslash character

caksoylar reviewed Mar 22, 2026

View reviewed changes

newx-it added 2 commits March 22, 2026 21:47

Renamed config flags

2441c4b

Renamed both config flags, slightly changed syntax to support the swap from "allow" to "prevent" for the USB power flag.

Fix formatting for pre-commit

c5c30a1

fix formatting according to pre-commit's preferences

Updated docs to note interaction with sleep timer

6bfae52

Added documentation for the interaction between BT connection keeping the device awake and the sleep timer. When the device loses connection after the sleep timer has elapsed, it will immediately sleep.

caksoylar reviewed Mar 29, 2026

View reviewed changes

fix: docs formatting

039d460

renamed flag names in docs to match previous changes

caksoylar reviewed Mar 29, 2026

View reviewed changes

fix: remove redundant kconfig default

8c9ec64

removed the redundante Kconfig "default n" value from the ZMK_SLEEP_PREVENT_WHILE_BLE_CONNECTED flag

caksoylar approved these changes Mar 30, 2026

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feats: prevent sleep while active BT profile connected and allow sleep while USB power connected#3288

feats: prevent sleep while active BT profile connected and allow sleep while USB power connected#3288
newx-it wants to merge 12 commits intozmkfirmware:mainfrom
newx-it:feat-ble-prevent-sleep-feat-usb-allow-sleep

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	config ZMK_BLE_PREVENT_SLEEP_WHILE_ACTIVE_CONNECTED
	config ZMK_SLEEP_PREVENT_WHILE_BLE_CONNECTED

	config ZMK_USB_ALLOW_SLEEP_WHILE_POWERED
	config ZMK_SLEEP_PREVENT_WHILE_USB_POWERED

	\| `CONFIG_ZMK_BLE_PREVENT_SLEEP_WHILE_ACTIVE_CONNECTED` \| bool \| Prevent sleeping while the active BT profile is connected. If the device loses connection after the sleep timer, it will sleep immediately \| n \|
	\| `CONFIG_ZMK_SLEEP_PREVENT_WHILE_BLE_CONNECTED` \| bool \| Prevent sleeping while the active BT profile is connected. If the device loses connection after the sleep timer, it will sleep immediately \| n \|

	\| `CONFIG_ZMK_USB_PREVENT_SLEEP_WHILE_POWERED` \| bool \| Prevent sleeping while USB power is connected \| y \|
	\| `CONFIG_ZMK_SLEEP_PREVENT_WHILE_USB_POWERED` \| bool \| Prevent sleeping while USB power is connected \| y \|

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newx-it commented Mar 19, 2026

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