HID, 3-Key Macroboard, and L1KVM

[xlegs]

I recently purchased a cheap macroboard (https://www.amazon.com/dp/B0BDRPQLW1) to easily switch inputs on my Level1KVM.

I have it plugged in to the front HID input of the switch, but I can’t get the keyboard to switch the inputs.

I used the software to program LCtrl+LCtrl+1, but it does not trigger the switching mechanism. I used HID Dump on my Linux box, and I got this:

001:013:001:DESCRIPTOR         1678642869.476015
 05 01 09 00 A1 01 09 01 15 00 25 FF 95 08 75 08
 81 02 09 01 91 02 C0

001:013:000:DESCRIPTOR         1678642869.522015
 05 01 09 06 A1 01 85 01 05 07 19 E0 29 E7 15 00
 25 01 75 01 95 08 81 02 95 01 75 08 81 01 95 03
 75 01 05 08 19 01 29 03 91 02 95 05 75 01 91 01
 95 06 75 08 15 00 25 FF 05 07 19 00 29 FF 81 00
 C0 05 0C 09 01 A1 01 85 03 05 01 09 81 09 82 75
 01 95 02 81 02 95 06 75 01 81 03 05 0C 95 01 75
 10 19 00 2A 2E 02 26 2E 02 81 00 C0 05 01 09 02
 A1 01 85 02 09 01 A1 00 05 09 19 01 29 05 15 00
 25 01 95 05 75 01 81 02 95 01 75 03 81 03 05 01
 09 30 09 31 09 38 15 81 25 7F 75 08 95 03 81 06
 C0 C0

Starting dumping interrupt transfer stream
with 1 minute timeout.

001:013:000:STREAM             1678642873.126827
 01 01 00 00 00 00 00 00 00

.001:013:000:STREAM             1678642873.429854
 01 00 00 00 00 00 00 00 00

.001:013:000:STREAM             1678642873.732886
 01 01 00 00 00 00 00 00 00

.001:013:000:STREAM             1678642874.034918
 01 00 00 00 00 00 00 00 00

.001:013:000:STREAM             1678642874.337968
 01 00 00 1E 00 00 00 00 00

.001:013:000:STREAM             1678642874.839008
 01 00 00 00 00 00 00 00 00

.001:013:000:STREAM             1678642874.860997
 02 00 00 00 00

Is that last phantom key? Maybe it’s a timing problem (each press is 500ms apart)? Does anybody know what’s going on here?

Thanks

[xlegs]

After a bit more experimentation, my macroboard has an extra 01 at the left-hand side of each key. For example:

The letter a on my Macroboard: 01 00 00 04 00 00 00 00 00
The letter a on my Das Keyboard: 00 00 04 00 00 00 00 00

Would this discrepancy prevent my keypad from triggering the KVM switch? Is there a workaround, or is the macroboard useless for this?

[wendell]

That macroboard seems useless, you might try one of the others that have been tested to work fine here. Avoid macroboards with bit banged USB implementations too like on the atmel avr,… it also does strange stuff

[Level1_Amber]

You might have seen this in the KVM FAQ → here

There is a Github repository → here from @SgtAwesomesauce and forum post → here.

[SgtAwesomesauce]

I’ve had issues with macroboards in the past. My implementation has been working absolutely wonderfully for damn near a year now. Never had to power cycle it never had any strange behavior. Can’t say it’s the most elegant implementation, but it works