Frequently Asked Questions


How do I flash my keyboard with Keyboard Firmware Builder (a.k.a

Don't use as it is outdated and does not support split keyboards. Use QMK Configurator instead.

Do I need to have the TRRS cable plugged in while trying to flash both halves?#

Having the TRRS cable plugged in while flashing has zero effect on flashing. Having it plugged in will not flash both halves at the same time.

Flashing does not occur over the TRRS cable, so it does not matter if the TRRS cable is plugged in or not while flashing. Each half needs to be plugged in individually to the USB port to be flashed.

When I flash the right side by itself, I get the left side, but mirrored. Is something wrong?#

Nope, this is perfectly normal!

Here's the explanation why:

Unless you explicitly do #define EE_HANDS in your keymap (this is not the default), QMK automatically assumes that whatever half the USB cable is plugged into is the left hand board. Even flashing the .eep files in this case does nothing, as it's ignored unless EE_HANDS is explicitly set.

So when you plug in the right board itself, it thinks it's the left one. The reason it's flipped is because the PCB has been physically flipped compared to the actual left board.

When you plug the TRRS cable in, the right side now auto detects correctly as the right side, and the firmware also knows to flip the board.


What's the pinout of the ICSP header on some of the PCBs?#

Which way do I orient the diodes?#

For all of the boards made by Keebio, the band on the diode (the cathode) is always associated with the square pad. On most boards, the square pad is pointing towards the bottom. For some PCBs that support Kailh Low-Profile switches, the square pad may be pointing towards the top.

Simple rule to remember: Band = Square Pad

Which way do I orient the resistors?#

Resistors have no polarity, so the direction they are installed does not matter

Do any of the PCBs have individually addressable LEDs?#

No, the PCBs that do have LED support can only be controlled as a group.

One option around this is to use a switch with clear housing like a Zealio or Alias switch and point RGB LEDs upwards through the switch

Which in-switch LEDs are compatible?#

Compatible sizes: 1.8mm, 2x3x4mm, or 3mm, note that sometimes the 3mm LEDs can interfere with the keycaps

Which RGB LED strips are compatible?#

  • WS2811 and variants (WS2812, WS2812B, WS2812C, etc.)
  • SK6812


Will you be making the PCB files available for download?#

No, the PCB files will not be made available

How do I contribute to the documentation here?#

The repository for this website can be found here: Keebio Docs on GitHub, we welcome any pull requests

Which type of switches do I have to use, PCB mount or Plate mount ones?#

The only difference between the two is that PCB mount has two additional plastic legs for better alignment on a PCB. Either type is compatible, and if given the choice, PCB mount is preferable to keep switches aligned better.

What the heck is I2C, and what do I need it for?#

The default firmware uses serial communication between the two halves using a single pin of the TRRS cable. Serial communication only allow for communication between two parts, which is fine for almost all builds.

However, in the future, there might be additional parts that you can add, like a numpad, OLED screen, etc. To support this, the communication protocol would need to be switched over I2C, which can support multiple devices. Additionally, the latency between halves is lower using the I2C protocol, which can help if you are a fast typer.

To add support for I2C, all you need to do is add the 2 4.7kΩ resistors to one of the halves (other half does not need them). Also, it doesn't hurt to add these resistors if using serial communication.

tl;dr: Adding this is optional, but you might as well do it as it's only 2 more components to solder.