Consider the humble calculator. Now just an app that you always have with you on your telephone, an electronic calculator used to be a technological marvel.
In this project, you'll build your own calculator with an Adafruit Feather RP2040, 128x64 OLED display, and 20 keys. Optional 3D printed parts like an enclosure and even the keycaps themselves make for a sharp presentation. Make it your own by customizing the code, or use the hardware for your own MacroPad-inspired project.
This project needs a custom PCB. You can pick up the KiCad (design) files or the Gerber (production) files below and upload them to the PCB house of your choice, or you can use this link to order them from OSH Park. You are free to modify the design files and use them in your own designs. (In copyright terms, the design files are licensed as CC0)
OSH Park's standard turnaround is 9 to 12 days from order to shipment, so plan accordingly.
The board files were designed in KiCad, open source software that is free to download & use.
Along with the custom PCB, you'll need basic tools, soldering supplies, and the Adafruit parts listed below.