pimentoso / touhoupad

A small 9-key mechanical gamepad to play Touhou project shoot-em-ups.

Ergonomic gamepad to play Touhou Project games. Left-hand controls shoot/slow/bomb, and right hand controls movement. The bomb button is supposed to be pressed with the left thumb.

More pictures at Thingiverse -> https://www.thingiverse.com/thing:4088449

Materials needed

• 9 cherry MX compatible switches
• 9 keycaps
• 12mm M3 countersunk screws (2x) (10mm or 16mm should be fine as well)
• M3 nuts (2x)
• an Arduino Pro Micro (5v model)
• optionally, 9 Amoeba single switch PCBs for a cleaner wiring job
• soldering iron and wires
• a 3d printer

The pad has only 9 keys so we can just make a single row with 9 columns, so there's no need for diodes.

If you use the amoebas for the wiring, make sure to bridge the diode pads/holes since they're not used. This is easily done by placing some solder on the SMD diode pads until they are connected (you can also use a small strand of wire or a piece of diode leg)

Building instructions

• Print the plate face down. Use 0.2mm layer height with no supports. The first layer has small text on it so print it slowly to ensure bed adhesion.
• Print the case. Punch open the screw holes, and push the M3 nuts into the hexagonal slots at the bottom.
• Insert the switches into the plate and handwire them to the Pro Micro (schematics are below).
• Slide the Pro Micro into its slot and drop the plate into the case.
• Screw the plate to the case making sure you aren't squeezing some wires on the screw poles.
• Flash the firmware (instructions below).
• Done!

Wiring table

matrix pin	firmware pin	pro micro pin
Row 0	F4	A3
Column 0 (left shift)	F5	A2
Column 1 (Z key)	F6	A1
Column 2 (X key)	F7	A0
Column 3 (left arrow)	D7	6
Column 4 (down arrow)	C6	5
Column 5 (right arrow)	D4	4
Column 6 (up arrow)	D0	3
Column 7 (esc key)	B1	15
Column 8 (enter key)	D1	2

Schematics

(note: it's the bottom view of the plate)

Firmware

You can load the touhoupad.json file into https://kbfirmware.com/ and edit the keys. Use the compile function on that site to get the hex file.

I use QMK toolbox [https://github.com/qmk/qmk_toolbox] for easy flashing. There's a precompiled hex file in the firmware folder.

If you need to flash it after assembling, there's a hole on the bottom you can use for shorting the RESET and GROUND pins, to enter flashing mode. Stick a bent paperclip in it or something.

Keyboard Layout Editor link

http://www.keyboard-layout-editor.com/##@_name=Touhou%20pad%3B&@_y:1.75&x:4.5&a:7%3B&=up%3B&@_x:1.5%3B&=x&_x:1%3B&=left&=down&=right%3B&@_r:15&rx:3.5&ry:1.25&y:-1&x:-1.25%3B&=esc&=enter%3B&@_r:45&rx:2.75&y:0.5&x:-2.25%3B&=shift&=z

3d printing directions

• use 0.2mm layer height.
• print the plate face down and VERY slow on the first layer for the letters to come out decent.
• no support needed, just punch open the screw holes after printing.