UHK80 - left part's LEDs turns off and on depending on halves' connection type

[nkoshcheev]

For some reason LED stays on regardless of LED timeout settings when both halves are interconnected with a spiral cable. My use-case is most of the time I use the keyboard in a wired mode.

When I disconnect the spiral cable, the left half backlight works properly.
Also when the halves are connected, mod / fn / mouse layer only change the backlight on the right half of my UHK.

Other than that the left half seems to work correctly, e.g. mod layer combinations I have on the left half work fine. Halves' link status changes correctly if I unplug the cable.

Firmware version - 15.0.1.

I'm also attaching my current configuration.

currentconfig.json

[kareltucek]

Let's try to debug this:

• Flash this firmware: uhk-firmware-15.0.1-backlight_hunt_v1.0.tar.gz
• Go to Agent logging:
  • Open About page
  • Click Agent logo 7x
  • Scroll left pane up
  • Click the new "Advanced settings" entry
  • Click Zephyr logging
  • Check right.
• Pick up stopwatch, then:
  • tap a key
  • hands off keyboard
  • start the stopwatch
  • wait for your timeout
  • now remember where the log ended.
• Copy and paste the log here, ideally using another keyboard (to avoid polluting the log)

[nkoshcheev]

2025-08-01 18:05:39 | UHK 80 right | LedManager_UpdateSleepModes: elapsedTime: 0, keyBacklightTimeout: 10000, KeyBacklightSleepModeActive: 0
LedManager_UpdateSleepModes: elapsedTime: 0, keyBacklightTimeout: 10000, KeyBacklightSleepModeActive: 0
recalculateLedBrightness: gSleep: 0, gAO: 0, KBSleep: 0, Powersaving: 0, BMode: 0, KBBB: 158, DB: 255Uart: didn't receive ack 238551, resending
Uart: didn't receive ack 238664, resending
Uart: didn't receive ack 238777, resending
Uart: didn't receive ack 238890, resending
Uart: didn't receive ack 239003, resending
Repeatedly failed to send a message! 84 86 13 86 119 4 3 55 1 15 0 158
2025-08-01 18:05:39 | UHK 80 right | 255 255 255 255 0 0 0 0 0 0 0 0 0 0 0
2025-08-01 18:05:39 | UHK 80 right | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
2025-08-01 18:05:40 | UHK 80 right | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
2025-08-01 18:05:40 | UHK 80 right | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 85
Uart: didn't receive ack 240337, resending
Uart: didn't receive ack 240450, resending
2025-08-01 18:05:40 | UHK 80 right | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
2025-08-01 18:05:41 | UHK 80 right | 0 0 0 0 0 0 0 85
Uart: didn't receive ack 240908, resending
2025-08-01 18:05:41 | UHK 80 right | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
2025-08-01 18:05:41 | UHK 80 right | 0 0 0 0 0 85
Uart: didn't receive ack 241479, resending
2025-08-01 18:05:41 | UHK 80 right | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
2025-08-01 18:05:42 | UHK 80 right | 0 0 0 0 0 0 85
Uart: didn't receive ack 242050, resending
2025-08-01 18:05:42 | UHK 80 right | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
2025-08-01 18:05:42 | UHK 80 right | 0 0 0 0 0 0 0 85
Uart: didn't receive ack 242621, resending
2025-08-01 18:05:43 | UHK 80 right | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
2025-08-01 18:05:43 | UHK 80 right | 0 0 0 0 0 85
Uart: didn't receive ack 243193, resending
2025-08-01 18:05:43 | UHK 80 right | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
2025-08-01 18:05:43 | UHK 80 right | 0 0 0 0 0 85
2025-08-01 18:05:49 | UHK 80 right | LedManager_UpdateSleepModes: elapsedTime: 9944, keyBacklightTimeout: 10000, KeyBacklightSleepModeActive: 0
LedManager_UpdateSleepModes: elapsedTime: 10000, keyBacklightTimeout: 10000, KeyBacklightSleepModeActive: 1
LedManager_UpdateSleepModes: elapsedTime: 10001, keyBacklightTimeout: 10000, KeyBacklightSleepModeActive: 1
recalculateLedBrightness: gSleep: 0, gAO: 0, KBSleep: 1, Powersaving: 0, BMode: 0, KBBB: 0, DB: 255Uart: didn't receive ack 248606, resending
Uart: didn't receive ack 248719, resending
Uart: didn't receive ack 248833, resending
Uart: didn't receive ack 248947, resending
2025-08-01 18:05:49 | UHK 80 right | Uart: didn't receive ack 249061, resending
Repeatedly failed to send a message! 84 86 113 86 250 4 3 64 1 15 0 0
2025-08-01 18:05:49 | UHK 80 right | 255 255 255 255 0 85

[nkoshcheev]

Additional observation: it seems that there is some sort of sync issue - if I reconnect the halves when the left side is dark, it stays that way. And in this case also, from functional perspective, everything works as expected (layers, keystrokes, etc), only the backlight logic is faulty.

[mondalaci]

I can't reproduce this issue on my UHK 80 with the spiral cable attached and with firmware 15.1.0. The lights go out as expected. Does the issue persist with firmware 15.1.0?

When I disconnect the spiral cable, the left half backlight works properly.

Only the left half backlights go out, but not the right half backlights?

[kareltucek]

This is related to the bridge cable issues seen in the log - therefore you can't reproduce it.

Still, even despite them the sync should sooner or later reach left half.

I.e., this definitely is a bug that needs a firmware fix.

@nkoshcheev you definitely should check your cable.

I am busy these days, so I won't get around to it anytime soon.

[nkoshcheev]

The issue is still reproducible both with the cable shipped with UHK80 and older (perhaps not compatible though, I just made an assumption it might work) cable from UHK60.

Only the left half backlights go out, but not the right half backlights?
Yes, only the left. It seems that the state always remain the same:

• if left half is dark and the cable is connected, it will stay dark even after a keystroke
• if left half is lit and cable is connected, it will stay lit after all the timeouts pass

However, I don't see any eventual synchronisation. Essentially if the keyboard is unplugged from the power source, left half drains battery within a day (which is expected since it's glowing)

[kareltucek]

they are indeed not compatible - one is straight, other is cross-wired.

[nkoshcheev]

I actually have an older spare UHK60 cable - I guess as an experiment I could also rewire it and try again.

[mondalaci]

@nkoshcheev Please do not use your UHK 60 spiral cable with your UHK 80 because they're completely incompatible despite their similar looks. The wiring has been reversed.

[nkoshcheev]

What I meant is that I had similar connectors and could reroute the wires especially if there is a wiring diagram available.

[mondalaci]

Ah, gotcha! See https://ultimatehackingkeyboard.com/modding/can-i-have-a-longer-bridge-cable

[Sheldon-Cole]

Hello everyone! I was directed here by @mondalaci via support as I've been experiencing something that looks to be exactly like described by @nkoshcheev. I have followed @kareltucek instructions and managed to get some logs.

Just so we're on the same page: with the serial cable disconnected, if I hold the Mod key and connect the serial cable, then release the Mod key, the LED's on the left-half stay backlit as the Mod layer. However, the keyboard will function as if it were in the QWERTY layer. This happens regardless of which function key is pressed when the serial cable is connected.

Within a few seconds of removing the serial cable, the left-half will begin to function normally again. This happens regardless of the connection method to the computer.

---

Log Files

Keypress with both halves connected via serial cable

2025-08-14 19:07:35 | UHK 80 right    | Uart: didn't receive ack 108730, resending
Uart: didn't receive ack 108843, resending
Uart: didn't receive ack 108957, resending
Uart: didn't receive ack 109070, resending
Uart: didn't receive ack 109184, resending
Repeatedly failed to send a message! 84 86 115 86 1 4 3 31 1 14 2 85
2025-08-14 19:07:36 | UHK 80 right    | Uart: didn't receive ack 109286, resending
Uart: didn't receive ack 109400, resending
Uart: didn't receive ack 109514, resending
Uart: didn't receive ack 109628, resending
Uart: didn't receive ack 109741, resending
Repeatedly failed to send a message! 84 86 54 86 217 4 3 32 1 14 0 85
2025-08-14 19:07:51 | UHK 80 right    | Batteries: 100% 100% (4082 4146)

Logs immediately after connecting the left to right half via serial cable

2025-08-14 19:04:39 | UHK 80 right    | Conn state: UartLeft(Ready)
Resetting left right link! Bidirectional
Uart: didn't receive ack 471859, resending
Uart: didn't receive ack 471973, resending
Uart: didn't receive ack 472087, resending
Uart: didn't receive ack 472200, resending
Uart: didn't receive ack 472313, resending
Repeatedly failed to send a message! 84 86 141 86 17 4 3 0 1 19 85 
Uart: didn't receive ack 472414, resending
Uart: didn't receive ack 472528, resending
Uart: didn't receive ack 472642, resending
Uart: didn't receive ack 472756, resending
Uart: didn't receive ack 472871, resending
Repeatedly failed to send a message! 84 86 251 86 41 4 3 1 1 27 12 0 0 0 0 0 85
2025-08-14 19:04:40 | UHK 80 right    | Uart: didn't receive ack 472973, resending
Uart: didn't receive ack 473087, resending
Uart: didn't receive ack 473200, resending
Uart: didn't receive ack 473314, resending
Uart: didn't receive ack 473427, resending
Repeatedly failed to send a message! 84 86 167 86 204 4 3 2 1 26 0 85
2025-08-14 19:04:40 | UHK 80 right    | Uart: didn't receive ack 473528, resending
Uart: didn't receive ack 473642, resending
Uart: didn't receive ack 473757, resending
Uart: didn't receive ack 473871, resending
Uart: didn't receive ack 473985, resending
Repeatedly failed to send a message! 84 86 54 86 172 4 3 3 1 25 0 0 0 255 255 255 0 255 255 0 0 255 255 255 0 255 0 0 0 255 0 255 0 255 255 136 68 85 
Uart: didn't receive ack 474090, resending
2025-08-14 19:04:41 | UHK 80 right    | 255 255 1 27 255 255 255 1 6 255 255 255 1 25 255 255 255 1 5 255 255 255 65 0 255 255 255 65 0 255 255 255 65 0 255 255 255 3 0 255 255 255 3 0 255 255 255 1 44 255 255 255 85 
Uart: didn't receive ack 474663, resending
2025-08-14 19:04:41 | UHK 80 right    | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 76 0 0 0 1 42 0 0 0 1 40 0 0 0 1 44 255 255 255 85 
Uart: didn't receive ack 475231, resending
2025-08-14 19:04:42 | UHK 80 right    | Uart: didn't receive ack 475344, resending
Uart: didn't receive ack 475458, resending
Uart: didn't receive ack 475572, resending
Uart: didn't receive ack 475686, resending
Repeatedly failed to send a message! 84 86 225 86 201 4 3 6 1 14 0 85
2025-08-14 19:04:43 | UHK 80 right    | Uart: didn't receive ack 475787, resending
Uart: didn't receive ack 475900, resending
Uart: didn't receive ack 476013, resending
Uart: didn't receive ack 476127, resending
Uart: didn't receive ack 476240, resending
Repeatedly failed to send a message! 84 86 46 86 192 4 3 7 1 15 0 255 255 255 255 255 0 85
2025-08-14 19:04:43 | UHK 80 right    | 255 65 75 255 255 255 65 26 255 255 255 65 78 255 255 255 0 0 255 255 255 65 0 255 255 255 65 0 255 255 255 65 0 255 255 255 4 0 255 255 255 3 0 255 255 255 0 0 255 255 255 85 
Uart: didn't receive ack 476915, resending
2025-08-14 19:04:44 | UHK 80 right    | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 76 0 0 0 1 42 0 0 0 1 40 0 0 0 0 0 255 255 255 85 
Uart: didn't receive ack 477487, resending
2025-08-14 19:04:44 | UHK 80 right    | 255 255 0 0 255 255 255 0 0 255 255 255 5 0 255 255 255 0 0 255 255 255 65 0 255 255 255 65 0 255 255 255 65 0 255 255 255 3 0 255 255 255 0 0 255 255 255 0 0 255 255 255 85 
Uart: didn't receive ack 478058, resending
2025-08-14 19:04:45 | UHK 80 right    | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 76 0 0 0 1 42 0 0 0 1 40 0 0 0 0 0 255 255 255 85 
Uart: didn't receive ack 478631, resending
2025-08-14 19:04:45 | UHK 80 right    | 255 255 0 0 255 255 255 0 0 255 255 255 0 0 255 255 255 0 0 255 255 255 65 0 255 255 255 65 0 255 255 255 65 0 255 255 255 0 0 255 255 255 2 0 255 255 255 2 0 255 255 255 85 
Uart: didn't receive ack 479203, resending
2025-08-14 19:04:46 | UHK 80 right    | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 76 0 0 0 1 42 0 0 0 1 40 0 0 0 2 0 255 255 255 85 
Uart: didn't receive ack 479774, resending
2025-08-14 19:04:47 | UHK 80 right    | 255 255 0 0 255 255 255 5 0 255 255 255 0 0 255 255 255 0 0 255 255 255 0 0 255 255 255 0 0 255 255 255 0 0 255 255 255 0 0 255 255 255 0 0 255 255 255 0 0 255 255 255 85 
Uart: didn't receive ack 480345, resending
2025-08-14 19:04:47 | UHK 80 right    | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 76 0 0 0 1 42 0 0 0 1 40 0 0 0 0 0 255 255 255 85 
Uart: didn't receive ack 480916, resending
2025-08-14 19:04:48 | UHK 80 right    | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 85 
Uart: didn't receive ack 481485, resending
2025-08-14 19:04:48 | UHK 80 right    | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 85 
Uart: didn't receive ack 482055, resending
2025-08-14 19:04:49 | UHK 80 right    | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 85 
Uart: didn't receive ack 482628, resending
2025-08-14 19:04:49 | UHK 80 right    | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 85 
Uart: didn't receive ack 483202, resending
2025-08-14 19:04:50 | UHK 80 right    | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 85 
Uart: didn't receive ack 483774, resending
2025-08-14 19:04:51 | UHK 80 right    | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 85 
Uart: didn't receive ack 484346, resending
2025-08-14 19:04:51 | UHK 80 right    | 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
2025-08-14 19:04:52 | UHK 80 right    | 85 
Uart: didn't receive ack 484919, resending
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
2025-08-14 19:04:52 | UHK 80 right    | 0 85 
Uart: didn't receive ack 485491, resending
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
2025-08-14 19:04:53 | UHK 80 right    | 0 0 85 
Uart: didn't receive ack 486063, resending
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
2025-08-14 19:04:53 | UHK 80 right    | 85 
Uart: didn't receive ack 486635, resending
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
2025-08-14 19:04:54 | UHK 80 right    | 0 85 
Uart: didn't receive ack 487209, resending
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
2025-08-14 19:04:55 | UHK 80 right    | 85 
Uart: didn't receive ack 487781, resending
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
2025-08-14 19:04:55 | UHK 80 right    | 85 
Uart: didn't receive ack 488352, resending
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 85 
Uart: didn't receive ack 488922, resending
2025-08-14 19:04:56 | UHK 80 right    | Uart: didn't receive ack 489036, resending
Uart: didn't receive ack 489150, resending
Uart: didn't receive ack 489263, resending
Uart: didn't receive ack 489377, resending
Repeatedly failed to send a message! 84 86 93 86 65 4 3 30 1 33 0 85

Attempted re-pairing halves with serial cable connected

[DeviceService] start Left half pairing
[DeviceService] stop poll UHK Device
[DeviceService] stopped poll UHK Device
[ZephyrLogService | UHK 80 left] Disabling
[ZephyrLogService | UHK 80 left] wait until polling
[ZephyrLogService | UHK 80 left] stopped
[ZephyrLogService | UHK 80 left] releaseOperations
[ZephyrLogService | UHK 80 left] releasing instances
[UhkHidDevice] Device communication closing.
[UhkHidDevice] Device communication closed.
[ZephyrLogService | UHK 80 left] instances are released
[ZephyrLogService | UHK 80 left] Disabled
[DeviceOperation] Device BLE address:  e9:0b:9a:77:10:ec
[UhkHidDevice] Available devices unchanged
[UhkHidDevice] Used device: {"vendorId":"0x37A8","productId":"0x7","path":"\\\\?\\HID#VID_37A8&PID_0007&MI_02#a&2e0664ed&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}","serialNumber":"2332900632","manufacturer":"Ultimate Gadget Laboratories","product":"UHK 80 Left USB","release":1,"interface":2,"usagePage":65280,"usage":1}
[UhkHidDevice] productId: 7 protocol versions: {"firmwareVersion":"15.0.1","deviceProtocolVersion":"4.16.1","moduleProtocolVersion":"4.3.0","userConfigVersion":"12.0.0","hardwareConfigVersion":"1.0.0","smartMacrosVersion":"3.7.0"}
[DeviceOperation] Left half BLE address:  e6:cc:a8:6b:13:98
[DeviceOperation] Device switching to pairing mode
[DeviceOperation] Left half switching to pairing mode
[DeviceOperation] Device delete left half bond
[DeviceOperation] Left half delete all bonds
[DeviceOperation] Device read pairing info
[DeviceOperation] Left half read pairing info
[DeviceOperation] Left half set pairing info
[DeviceOperation] Device set pairing info
[DeviceOperation] Left half pair peripheral
[DeviceOperation] Device pair central
[DeviceOperation] Left half waiting for pairing finished
[UhkHidDevice] Device communication closing.
[UhkHidDevice] Device communication closed.
[DeviceService] Left half pairing failed Error: [DeviceOperation] Left half pairing timeout
    at qr (C:\Users\Sheldon\AppData\Local\Programs\uhk-agent\resources\app.asar\electron-main.js:5:538444)
    at async ri.pairToLeftHalf (C:\Users\Sheldon\AppData\Local\Programs\uhk-agent\resources\app.asar\electron-main.js:5:596126)
    at async ro.startLeftHalfPairing (C:\Users\Sheldon\AppData\Local\Programs\uhk-agent\resources\app.asar\electron-main.js:5:654154)
    at async Ks.process (C:\Users\Sheldon\AppData\Local\Programs\uhk-agent\resources\app.asar\electron-main.js:5:626600)
[DeviceService] Device force reenumerate
[UhkHidDevice] Device communication closing.
[UhkHidDevice] Device communication closed.
[UhkHidDevice] Device communication closing.
[UhkHidDevice] Start reenumeration, mode: NormalKeyboard, timeout: 5000ms
[UhkHidDevice] Reenumeration error. We hope it would not break the process Error: Cannot write to hid device
[UhkHidDevice] closing normal keyboard after reenumeration
[UhkHidDevice] Could not find reenumerated device: NormalKeyboard. Waiting...
[UhkHidDevice] Available devices changed.
[UhkHidDevice] Removed: {"vendorId":"0x37A8","productId":"0x9","path":"\\\\?\\HID#VID_37A8&PID_0009&MI_02#a&98600e7&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}","serialNumber":"2332900632","manufacturer":"Ultimate Gadget Laboratories","product":"UHK 80 Right USB","release":1,"interface":2,"usagePage":65280,"usage":1}
[UhkHidDevice] Removed: {"vendorId":"0x37A8","productId":"0x9","path":"\\\\?\\HID#VID_37A8&PID_0009&MI_03#a&2d5d3ea9&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}","serialNumber":"2332900632","manufacturer":"Ultimate Gadget Laboratories","product":"UHK 80 Right USB","release":1,"interface":3,"usagePage":12,"usage":1}
[UhkHidDevice] Removed: {"vendorId":"0x37A8","productId":"0x9","path":"\\\\?\\HID#VID_37A8&PID_0009&MI_00#a&28db096&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}\\KBD","serialNumber":"2332900632","manufacturer":"Ultimate Gadget Laboratories","product":"UHK 80 Right USB","release":1,"interface":0,"usagePage":1,"usage":6}
[UhkHidDevice] Could not find reenumerated device: NormalKeyboard. Waiting.....
[UhkHidDevice] Available devices changed.
[UhkHidDevice] Added: {"path":"COM5","manufacturer":"Microsoft","serialNumber":"9&31FAA01F&0&0000","pnpId":"USB\\VID_37A8&PID_0008&MI_00\\9&31FAA01F&0&0000","locationId":"002f.0000.0003.001.003.001.004.000.000","friendlyName":"USB Serial Device (COM5)","vendorId":"0x37A8","productId":"0x0008"}
[UhkHidDevice] Could not find reenumerated device: NormalKeyboard. Waiting..............................
[UhkHidDevice] Available devices changed.
[UhkHidDevice] Removed: {"path":"COM5","manufacturer":"Microsoft","serialNumber":"9&31FAA01F&0&0000","pnpId":"USB\\VID_37A8&PID_0008&MI_00\\9&31FAA01F&0&0000","locationId":"002f.0000.0003.001.003.001.004.000.000","friendlyName":"USB Serial Device (COM5)","vendorId":"0x37A8","productId":"0x0008"}
[UhkHidDevice] Could not find reenumerated device: NormalKeyboard. Waiting......
[UhkHidDevice] Reenumerating devices
[DeviceService] Device force reenumerate done
[UhkHidDevice] Device communication closing.
[DeviceService] Left half force reenumerate
[UhkHidDevice] Device communication closing.
[UhkHidDevice] Start reenumeration, mode: NormalKeyboard, timeout: 5000ms
[UhkHidDevice] Reenumeration error. We hope it would not break the process Error: Cannot write to hid device
[UhkHidDevice] closing normal keyboard after reenumeration
[UhkHidDevice] Could not find reenumerated device: NormalKeyboard. Waiting...
[UhkHidDevice] Available devices changed.
[UhkHidDevice] Removed: {"vendorId":"0x37A8","productId":"0x7","path":"\\\\?\\HID#VID_37A8&PID_0007&MI_00#a&7a62c71&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}\\KBD","serialNumber":"2332900632","manufacturer":"Ultimate Gadget Laboratories","product":"UHK 80 Left USB","release":1,"interface":0,"usagePage":1,"usage":6}
[UhkHidDevice] Removed: {"vendorId":"0x37A8","productId":"0x7","path":"\\\\?\\HID#VID_37A8&PID_0007&MI_03#a&59bb724&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}","serialNumber":"2332900632","manufacturer":"Ultimate Gadget Laboratories","product":"UHK 80 Left USB","release":1,"interface":3,"usagePage":12,"usage":1}
[UhkHidDevice] Removed: {"vendorId":"0x37A8","productId":"0x7","path":"\\\\?\\HID#VID_37A8&PID_0007&MI_02#a&2e0664ed&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}","serialNumber":"2332900632","manufacturer":"Ultimate Gadget Laboratories","product":"UHK 80 Left USB","release":1,"interface":2,"usagePage":65280,"usage":1}
[UhkHidDevice] Added: {"vendorId":"0x37A8","productId":"0x9","path":"\\\\?\\HID#VID_37A8&PID_0009&MI_02#a&98600e7&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}","serialNumber":"2332900632","manufacturer":"Ultimate Gadget Laboratories","product":"UHK 80 Right USB","release":1,"interface":2,"usagePage":65280,"usage":1}
[UhkHidDevice] Added: {"vendorId":"0x37A8","productId":"0x9","path":"\\\\?\\HID#VID_37A8&PID_0009&MI_03#a&2d5d3ea9&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}","serialNumber":"2332900632","manufacturer":"Ultimate Gadget Laboratories","product":"UHK 80 Right USB","release":1,"interface":3,"usagePage":12,"usage":1}
[UhkHidDevice] Added: {"vendorId":"0x37A8","productId":"0x9","path":"\\\\?\\HID#VID_37A8&PID_0009&MI_00#a&28db096&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}\\KBD","serialNumber":"2332900632","manufacturer":"Ultimate Gadget Laboratories","product":"UHK 80 Right USB","release":1,"interface":0,"usagePage":1,"usage":6}
[UhkHidDevice] Could not find reenumerated device: NormalKeyboard. Waiting....
[UhkHidDevice] Available devices changed.
[UhkHidDevice] Added: {"path":"COM6","manufacturer":"Microsoft","serialNumber":"9&1C8B2544&0&0000","pnpId":"USB\\VID_37A8&PID_0006&MI_00\\9&1C8B2544&0&0000","locationId":"002f.0000.0003.001.004.001.000.000.000","friendlyName":"USB Serial Device (COM6)","vendorId":"0x37A8","productId":"0x0006"}
[UhkHidDevice] Could not find reenumerated device: NormalKeyboard. Waiting..............................
[UhkHidDevice] Available devices changed.
[UhkHidDevice] Removed: {"path":"COM6","manufacturer":"Microsoft","serialNumber":"9&1C8B2544&0&0000","pnpId":"USB\\VID_37A8&PID_0006&MI_00\\9&1C8B2544&0&0000","locationId":"002f.0000.0003.001.004.001.000.000.000","friendlyName":"USB Serial Device (COM6)","vendorId":"0x37A8","productId":"0x0006"}
[UhkHidDevice] Could not find reenumerated device: NormalKeyboard. Waiting.....
[UhkHidDevice] Reenumerating devices
[DeviceService] Left half force reenumerate done
[UhkHidDevice] Device communication closing.

[nkoshcheev]

An update from me - I have tried different (straight) cables (re-wired and factory new) and the issue still persists.

[kareltucek]

I am still in the dark as to why just you two are the only affected. Let's try to gather more evidence:

• Is typing rock solid, ir is the keyboard getting dropped or stuck keys from time to time too?
• can you reproduce it with a factory config?
• does it - failing led sync - happen every time you reconnect the cable?
• is there any unusual about your user configs? (esp., are you using macro commands in them?)
• are you using functional backlighting or per-key-rgb?
• is there any specific about your environment? (Like high elmag interference or many bluetooth connections around)
• anything comes to mind that could spin the mcu a lot?
• what firmware versions are affected? Would you give a try to the latest firmware of each majir version and report back? 13.x, 14.x, 15x
• does led sync fail only when the cable is reconnected, or every time it is supposed to take place - say when tapping a layer switch?

Will provide a modified firmware sometime next week that will provide more debug info.

[nkoshcheev]

Is typing rock solid, ir is the keyboard getting dropped or stuck keys from time to time too?

I have never noticed such behavior - hotkeys work well, no missing keystrokes, etc.

can you reproduce it with a factory config?

Yes, I am currently running a default.

does it - failing led sync - happen every time you reconnect the cable?

Yes, reproduces all the time.

is there any unusual about your user configs? (esp., are you using macro commands in them?)

No, I'm running a pretty much default config usually - except a macro for volume up/down for a right half.

are you using functional backlighting or per-key-rgb?

Functional.

is there any specific about your environment? (Like high elmag interference or many bluetooth connections around)

I am not sure interference is necessarily high, but I keep some devices around the keyboard (phone, smartwatch). With UHK60 the same setup did have an issue if I had a smartphone lying right between the halves, so I got rid of that habit :)

anything comes to mind that could spin the mcu a lot?

Frankly speaking, nothing. My use-case is pretty standard.

what firmware versions are affected? Would you give a try to the latest firmware of each majir version and report back? 13.x, 14.x, 15x

I would say 15.x, 14.x (IIRC I received the keyboard with 14.x preinstalled). I will of course try rolling back to see if that helps.

does led sync fail only when the cable is reconnected, or every time it is supposed to take place - say when tapping a layer switch?

Every time. So the mod layer, for example, only lights up properly if I have the halves disconnected, otherwise it's "dead" - backlight never turns on / off (depends on which state it had when the cable got connected), and even if it's on - tapping a layer only shows the layer on right half.