Mac OS BLE stack is a trashcan: possible workarounds.

[Na-Cly]

Pairing with Mac OS has been an overall negative experience that requires multiple resets of the keyboard and multiple resets of bluetooth settings on the mac, and when it does start working you've tried so many things you don't even remember how you got to where you are.

Here's behavior I've seen when pairing and unpairing from mac os:

1. Initial connection looks like it establishes fine but no key presses are registered.
2. Disconnecting the keyboard by clearing the bond causes issues reconnecting the keyboard to the mac.

Since the improved bluetooth profiles were released this has been significantly helped as now if the connection is established and working it will usually continue working and an occasional reset of central is required after a reboot.

There are ways to get it working with a couple of reboots but I wanted a method of restoring connectivity without rebooting. So far this is the method I've come up with:

1. Clear bond on keyboard
2. Remove device from mac from debug menu
3. Reset bluetooth device from debug menu
4. rm ~/Library/Preferences/ByHost/Bluetooth && sudo pkill blued

This has been the best to get the keyboard working again without rebooting.

[Na-Cly]

It should be noted this workaround didn’t work the last time I tried it, so it’s definitely not a fix every time.

[pluskid]

2. Remove device from mac from debug menu

Where can I find the "debug menu"?

[adamcstephens]

Where can I find the "debug menu"?

Hold shift and option while clicking the bluetooth menu bar icon

[j1n6]

another tip shared @petejohanson

[pluskid]

My Macbook constantly wake itself up from sleep, and the battery drains over night. I suspect it is waken up by battery report or some other notification but it wake up even when I switch the keyboard to a different ZMK BLE profile. Unchecking the checkbox that allows bluetooth to wake up computer solves the issue, but for some mysterious reason my MacOS automatically re-check that box for me from time to time.

[petejohanson]

@pluskid do you have ZMK deep sleep enabled? We're almost ready to enable it by default, but if you haven't turned it on, doing so might help, since once the keyboard sleeps it will stop sending battery notifications.

[pluskid]

@petejohanson Cool! I will test it tonight.

Update: it did not work. pmset -g log shows DarkWake to FullWake from Deep Idle [CDNVA] : due to HID Activity Using AC (Charge:100%). I was not able to see anything suspicious from USB logging (when the keyboard is connected to another computer). Currently the only workaround that works is unchecking 'Allow Bluethooth devices to wake this computer', and the main pain point is that that checkbox somehow get checked again automatically by some mysterious force.

[pluskid]

@petejohanson Enabling deep sleep did not work, but my guess is it has not really entered deep sleep stage yet. For my case, the laptop wakes up almost within 1 minute of being put to sleep, which is definitely before the deep sleep kicks in. Is there way to trigger the deep sleep manually using a key press? Or are we able to config the sleep timeout to be a very short one for debugging purpose?

[carbncl]

We've just merged the update to Zephyr 2.4.0, which brings some major BT stability improvements (macOS!)

Does this mean this issue is resolved?

Is Mac OS BLE really a trash can? ;p

[j1n6]

I’m using it daily, still have drops occasionally.

…

Sent from my iPhone

On 14 Dec 2020, at 21:30, carbncl ***@***.***> wrote:  We've just merged the update to Zephyr 2.4.0, which brings some major BT stability improvements (macOS!) Does this mean this issue is resolved? Is Mac OS BLE really a trash can? ;p — You are receiving this because you commented. Reply to this email directly, view it on GitHub, or unsubscribe.

[carbncl]

Oh also, does this solve the constant wake from sleep of macOS?

[j1n6]

Nope

…

Sent from my iPhone

On 14 Dec 2020, at 21:33, carbncl ***@***.***> wrote:  Oh also, does this solve the constant wake from sleep of macOS? — You are receiving this because you commented. Reply to this email directly, view it on GitHub, or unsubscribe.

[petejohanson]

Nope
…
Sent from my iPhone
On 14 Dec 2020, at 21:33, carbncl @.***> wrote:  Oh also, does this solve the constant wake from sleep of macOS? — You are receiving this because you commented. Reply to this email directly, view it on GitHub, or unsubscribe.

My suspicion is that the BAS notifications are causing the wake-up. We may need to enhance the BAS stuff to check for any subscriptions to the notification before sending; upstream Zephyr battery service may not do that, and so that may be causing issues.

[j1n6]

I will recompile the firmware and confirm the new updates behaviours.