ErgoSnap Keyboard

WARNING. This is rev1.1, which works fine but has a few issues:

• The silkscreen for the ProMicro outline is incorrect for the USB-up placement
• USB cable only just plugs into the ProMicro on the left half (plug shroud is against the edge of the PCB below the ProMicro)
• SDA & SCL are the wrong way around on the 5pin header for the Pimoroni trackball breakout, so that doesn't work without some jumper wires...

ErgoDash layout with Mitosis style PCB construction, reversible ProMicro chin from Ergo42.

• Removed all the wiring for backlight/underlight LEDs
• Uses through-switch diode holes
• M6 mouting holes on the "inside" board edges for tenting
• 5 pin connector for trackball module (no software yet...)

Fabrication

I got my PCBS made at JLCPCB. No issues.

BOM

• 4 x PCBs
• 68 x Keyswitches (Cherry MX or compatible)
• 68 x Diodes (1N4148)
• 2 x ProMicro + header pins
• 2 x TRRS jacks (PJ-320A aliexpress)
• 1 x TRRS cable
• 2 x 4k7 Ohm resistors (I2C pullups)
• 2 x 5pin headers
• 4 x M6 nylon screw thread + nuts (for tenting, optional)
• Some sticky-backed neoprene tape (for padding/non-slip on the bottom of the board)

Build

See build guide.

Software

QMK. ErgoSnap uses exactly the same matrix as the ErgoDash, so just build an ErgoDash layout (using the LAYOUT_3key_1us layout type).

For an example see my ergodash-isolike layout.

Example make command:

make ergodash/rev1:isolike:avrdude

License

ErgoDash & Ergo42 are MIT, Mitosis is GPLv3. So this work as a whole is GPLv3.