Here are the design files to make your very own hand wired Free42 calculator keyboard! (As seen on Reddit).
tl;dr - keycaps, case, firmware
Order your own set from WASD Keyboards!
- $60 - 61 keycap set, with this template
- $12 - R1 1x2.00, plus
- $12 - R1 1x2.00, minus
- $12 - R1 1x2.00, multiply
- $12 - R1 1x2.00, divide
Don't forget to set the keycap colors! All the keycaps are "charcoal", except the /? key (the one next to the right-shift), which is "orange".
You can print your own case, using this .stl file, or order one from Shapeways.
If you're new to hand wired keyboards, matt3o wrote a good guide.
For the microcontroller, I used an Arduino Pro Micro.
BOM:
- $25.99 - arduino
- $6.27 - usb micro extension
- $11.45 - connecting wire
- $14.69 - ribbon connectors
- $5.99 - diodes
- $8.99 - solder
- $15.99 - soldering iron
- $9.99 - rubber feet
- $29.99 - key switches
- $2.50 - 5 x stabilizer inserts
- $2.50 - 5 x stabilizer clips
- $2.50 - 5 x stabilizer springs
You can program the Arduino with QMK Toolbox, using this .hex firmware file.
To create your own layout, use the Keyboard Firmware Builder, with this .json file.
And here's the default layout.
Feel free to donate to the coffee fund :)