The DOOM Keeb will only have a single USB cable to plug into your computer. That cable runs to the CH334F mini USB hub's upstream port.
The keyboard's built-in controller will be plugged into one of the hub's downstream ports, and the KB2040 the other.
The KB2040 will have a NeoKey breakout plugged into it so that it can launch the ZDoom.exe file that's stored on the KB2040's flash memory when pressed.
Disconnect Keyboard Cable
The USB cable is plugged into the keyboard controller with a small connector.
Carefully unplug.
Cut the Cord
Cut the original cord about four inches from the interior connector -- we'll reuse that in a moment.
Strip some insulation from the USB cable as shown.
USB Cable to Hub
Strip and tin the four USB wires.
Solder these to the upstream port connections on the hub (the set of pads opposite of the USB C jack):
- Red to HOST PORT 5V
- Black to HOST PORT GND
- Green to HOST PORT D+
- White to HOST PORT D-
You've now got a two-port USB hub embedded in your keyboard case!
Keyboard Connection Cable
Remove the outer insulation and shielding from the keyboard cable you cut earlier.
Strip and tin the ends and then solder them to the mini USB hub's downstream port 1 as shown.
- black to USB hub PORT1 GND
- red to USB hub PORT1 5V
- green to USB hub PORT1 D+
- white to USB hub PORT1 D-
The white connector can be plugged into the keyboard's controller once we're ready for testing.
NeoKey Wiring
Cut an 8" length each of four wires for the NeoKey to connect to the KB2040.
Strip and tin the wires, then solder to the NeoKey and the KB2040:
- black from NeoKey - to KB2040 GND
- red from NeoKey + to KB2040 3V
- blue from NeoKey S+ to KB2040 A1
- yellow from NeoKey IN (NeoPixel In) to KB2040 A2
Also solder a short black wire from NeoKey S- to NeoKey - (this is what sends the switch to ground when it is in the unpressed state).
KB2040 Wiring
Cut an 5" length each of four wires for the KB2040 to connect to the hub's downstream port 2 connections.
Strip and tin the wires, then solder:
- black from KB2040 GND to USB hub PORT2 GND
- red from KB2040 RAW (5V) to USB hub PORT2 5V
- green from KB2040 D+ to USB hub PORT2 D+
- white from KB2040 D- to USB hub PORT2 D-
Connection Test
Plug the which keyboard driver connection back in so the keyboard can be enumerated on the hub.
Plug the USB cable into your computer -- the three green LEDs will light up to show that the hub has power and the two devices plugged into it have enumerated.
The KB2040's green status LED will light up, and the NeoKey will light up red.
Case Mod
In order to add the DOOM launch key properly, you'll need to cut a hole in the case right under the existing ESC key.
Measure & Mark
Measure the ESC key hole and mark the same size just below it -- calipers can be handy for this.
Score, Drill, Cut, File
Use a utility knife and straight edge to score the lines a bit deeper than the initial scribe lines.
You can drill the corners, too, then continue to cut or use a coping saw to remove the rest of the material.
Use a small file to clean up the edges, and round over a bevel to match the existing edges.
Key Fitting
Use some thick double-stick tape or Uglu dots to place the key lightly in place.
Line up the key more precisely with the top of the case in place, then press the key more securely.
Remove the case top and use hot glue to more securely afix the NeoKey breakout to the keyboard PCB.
You can now close up the keyboard case fully and screw it back together.
Custom Keycap Cover
You can print a 1" square keycap cover and fold it to fit inside the re-legendable keycaps as shown.
Text editor powered by tinymce.
