A what?

This is a fun desk toy that could have use as a macro pad if you mapped macros to the 8 bits. It’s a 2 key keyboard for the most tedious typing experience ever. The keyboard will have you type 8 bits, on the 8th bit entered it will send the connected computer the correlated ASCII code. Thus being a technically fully functioning keyboard using 2 keys.

01100001 = a
01100010 = b

00001000 = backspace

How to build

This is built pretty easily with an Arduino micro, 2 buttons( I used Cherry MX keyswitches) and an OLED(optional) display. The code is here. Download the code and map the pins for I2C control (2&3) to the OLED and 4+5 to the buttons and it will just work. It’s super simple.

Part list with links

• Arduino Micro (Not the pro micro)
• OLED Screen
• Green MX Switches

The PCB

The PCB was designed using EasyEDA, this was my first PCB design. I’ve done more since but this was a good starting point with no extra external components and just making connections.

The case

The case was modeled in Onshape, it’s VERY simple and was attached with hot glue, I’m going to update it to just clip to the binary keyboard. Here is the link if you’d like to try to modify it.

Future Plans

I’m making a new PCB at some point without using an Arduino board and just embedding the micro controller on the PCB itself.

Previous Builds

I have now gone back and remade this project a few times over about 7 years. It’s a simple project that I love to come back to with new skills I’ve learned and see what can be improved.

Version 1 when I got my first 3D printer

Version 0 from around 2016 right after I graduated High School: