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PolyKybd

Old Rev.2 Boards (2023)

This page is only for the old Rev.2 boards from 2023. Check the text printed on the back of each PCB:

Half Silkscreen
Left Rev 2 04/2023
Right Rev.2 03/2023

Boards marked rev3, rev3.1, rev3.2 or rev3.3 need nothing from this page.

Why an old Rev.2 board needs a setup step

Section titled “Why an old Rev.2 board needs a setup step”

A Rev.2 board sends USB power over the cable between the halves. The firmware detects which half is plugged into the computer by checking for USB power, so on a Rev.2 board both halves find power and both start as the main half. The halves then do not connect to each other: each half plays its startup animation, but keys and settings stay on their own half.

Each half therefore stores a Rev.2 mark next to its handedness. With the mark, the half that the computer recognises over USB becomes the main half, and the other half waits about 2 seconds at startup before it continues as the second half. The mark stays stored when the firmware is updated.

Before you start

Section titled “Before you start”
  • Flash the firmware to each half separately, over the UF2 bootloader drive. The update from the tray app sends the image to the second half over the split cable, and that link does not work on a Rev.2 board until both halves have the mark. See UF2 bootloader drive. Use the same .uf2 file for both halves.
  • Run only one PolyKybdHost. The tray app connects to a host that is already running in the background, and an older one stays running after you start a newer tray app. If About shows a protocol mismatch or the entries below are greyed out, stop the running host with polyctl shutdown, quit the tray icon and start the app again.

Set the mark on each half

Section titled “Set the mark on each half”
  1. Disconnect the cable between the halves.
  2. Connect only the left half to the computer with USB.
  3. Wait until the tray app has finished any font-pack update it starts for this half. This can take a few minutes the first time.
  4. In the tray menu, open Maintenance → Fix Left/Right Side → Mark connected half as a Rev.2 board (2023)… and choose Left. The half saves the mark and its side, then restarts.
  5. Disconnect the left half. Connect only the right half, wait for its font-pack update, and repeat step 4 with Right.
  6. Connect the cable between the halves, then connect either half to the computer. The halves now connect to each other.

From the command line, steps 4 and 5 are:

Terminal window
polyctl handedness left --split-vbus on     # with only the left half connected
polyctl handedness right --split-vbus on    # with only the right half connected

Check the result

Section titled “Check the result”

The firmware’s startup messages show the mark on the board: line. Open the keyboard console tab of the log viewer (Help & About → Log file…). After the half connected over USB restarts, it prints:

   board: flags=0x01 split_vbus (Rev.2: master by USB enumeration)

flags=0x00 means the half has no mark. The console shows only the half connected over USB, so check each half while it is the one connected.

Remove the mark

Section titled “Remove the mark”

Connect only the half to change. Use Maintenance → Fix Left/Right Side → Remove the Rev.2 mark from the connected half… and choose that half’s side, or run:

Terminal window
polyctl handedness left --split-vbus off    # with only the left half connected
polyctl handedness right --split-vbus off   # with only the right half connected

Both also save the side you name, so name the side of the connected half. Changing the side with Fix Left/Right Side alone keeps the mark.