A lot of people expressed interest in my shortcut keyboard from an old cash register, there were even a few articles written about it! I decided to make another one for a gift, but this time made with parts that anyone could buy online. If you’re looking for information to make one of these yourself, check out my Instructable and my last blog post.
Link to the code on GitHub: https://github.com/fwacer/mini-hotkeyboard
Photo gallery:
Schematic:
Keypad layout
| A | B | C | D | E | |
|---|---|---|---|---|---|
| 1 | Caps Lock (switch) | Change style to “Normal” (button in knob) | Volume mute (button in knob) | Types “asdf” (switch) | — |
| 2 | Increase font size | Paragraph indent | Change style to “Heading 1” | Change style to “Heading 2” | Change style to “Heading 3” |
| 3 | Decrease font size | Remove paragraph indent | Bullet point | En dash | Em dash |
Components information
– Mechanical switches – I found some on eBay with the title “16mm Square Momentary Push Button Switch LED Lamp 5-pins”
– Toggle switches – I found a bucket of these at a local hobby shop from a hobby train set. These are not necessary, but they look so cool!
– Rotary encoders – Also known as a knob. I recommend getting more expensive than the cheapest you can find on Amazon. I was unable to get the ones I had bought to work reliably, even after adding external circuitry to smooth out the pulses. I disabled their functionality in the code and gave the gift as it was.
– Pull up / pull down resistors – ~10 of value 10 kOhm.
– Hookup wire – I used 22 AWG solid core. In future, I should probably start using thinner multi-strand stuff.
– Arduino Pro Micro – or similar (knock off of same model is ok). Check compatibility here. Not all Arduinos can emulate a keyboard.
– Project Box – I opted to buy a plastic enclosure from an electronics store while I was visiting family in a bigger city. I didn’t want to make these one out of wood.