Test
You should now test that the work so far was successful. Any issues will be much easier to fix before switches are added.
The board halves should now look like this, though displayed here with the right MCU not yet inserted into its sockets.
Each MCU needs to be flashed with the firmware before the board can be tested. See QMK for instructions.
When plugging and unplugging your board, never plug or unplug the TRRS cable with the USB connected to either side. The TRRS carries power from one side to the other and you risk shorting out and damaging the MCU! Always disconnect the USB before plugging or unplugging the TRRS cable!
To test the keyboard, connect the two halfs and connect one via USB to the computer. See the Handedness Jumper page for which side should be connected to the computer. All of the LEDs should light up in red.
Test each switch location. To 'press' at each switch, short together the contacts of the footprint with tweezers.
You can see the keypresses with QMK configurator's key test page. It will flash and color in the keys as you send those keycodes from the keyboard.
The layer switch keys will not produce an immediate response. If everything else works, testing those can usually wait until you add some switches, or you can use two tweezers to short both the layer key and what would normally be an letter key to see that a symbol or number is produced.
If things do not work, it may be best to test one side at a time to isolate the issue. Remember that pressing a key may now produce a response on the other half of the keyboard in the mirrored location of that key press.
If you have:
- A row of switches that does not register: check the solder connection of that row at the MCU.
- A column that does not register: check that column connection at the MCU.
- Scattered single switches that do not register: check the solder connection for the diodes of those switches.
- Right side does not register when connected to the left: check the TRRS connections.
See the schematic for how the switch rows and columns are numbered and connected to pins on the MCU.
Next: Switches