Retrex rev 1.0

The Retrex rev 1.0 is the first functional version of the Retrex keyboard.

Summary

• Bill of materials
• Firmware
• RGB Underglow

Bill of materials

Qty	Item	Notes
70	Cherry MX compatible switches
70	Cherry MX hotswap sockets
2	Retrex PCBs
70	SOD-123 1N4148/1N4148W diodes	1N4148 THT diodes can also be used
2	PJ-320A 4 poles 3.5 mm TRRS connectors
2	4.7 kOhm resistors	Need to be soldered on one half only
2	Through hole momentary switch	Dimensions 6mm x 6mm x 4.3mm
2	JS102011SAQN SMT slide switch
2	Arduino Pro Micro compatible microcontrollers	Beware of the infamous Green Pro Micro, see note below.
1	TRRS cable
1	USB micro cable
70	Cherry MX compatible keycaps	10x 1.25u keycaps, 6x 1.5u keycaps, 54x 1u keycaps
*	neopixel leds	Optional RGB-underglow

Assembly guide

Installation steps:

• Solder components:
  1. Solder 1N4148 diodes. Keep the diode legs for the right hand controller installation.
  2. Solder PJ-320A connectors.
  3. Solder momentary switches.
  4. Solder 4.7k Ohm resistors on one half only. If you are going for the RGB-underglow ignore this step.
  5. Solder the Pro Micro header pins (do not solder the Pro Micro controllers yet). This step may differ depending on which case you're using. Refer to the following:
  • See 3D-Printed case right hand controller installation detail.
  • See Falbatech's bamboo case.
  • See socketed Pro Micro installation guide.
  6. Optional see RGB-underglow instructions.
• Flip the PCBs.
• Solder switches to the PCB.
  • If you want hot swappable switches, see the hot swappable switch instructions.
• Flip the PCBs again.
• Solder Pro Micros to the header pins following the PCB labeling. The Pro Micro on the right half should be installed with the bottom facing the Redox PCB, the Pro Micro on the left half should be installed with the bottom facing away from the PCB. See pictures for details.

Right hand back side:

Left hand back side:

Diode installation detail:

Firmware

This keyboard uses ZMK for building, so follow the instructions for installing and building in https://zmk.dev/docs/development/setup

The build command using docker is:

Run the build container

cd zmk_config
docker run -it -w /home/zmk -v $(pwd):/home/zmk/zmk-config:rw --name zmk_build zmkfirmware/zmk-build-arm:3.2-branch bash

Then inside the container execute:

git clone https://github.com/zmkfirmware/zmk.git
cd zmk
west init -l app/
west update

This takes a bit, after that exit the container

restart the container and then execute:

docker start -i zmk_build
cd /home/zmk/zmk/app
docker rm -f zmk_build

otherwise:

cd zmk_config
export RETREX_FOLDER=$(pwd) && echo $RETREX_FOLDER 
west build -b nrfmicro_13 -- -DZMK_CONFIG=$(RETREX_FOLDER)