“A minimalist 18 key numpad using the Seeed Studio XIAO RP2040, a single analogue pin, and room for expansion!
If you’re anything like me, you have a relatively modern and compact laptop as your main computing device - but it doesn’t have a numpad, it has a row of keys along the top. This is frustrating, as I do quite of bit of number input for both my day job and hobbies. So, I could buy a relatively cheap (and potentially wireless) numpad, I could buy a new laptop - or I could make a project out of it and design my own!Documented below is how I went about it, with the included files if you wish to make your own. It’s a real pleasure to use, and could be used for other purposes as well! Macropads are quite common nowadays, for gaming streaming, design, and more, and having a pad to suit your specific use case is very handy.
There are many custom-made keyboards and macropad examples out there, and for years people have used the Arduino Micro, due to it’s onboard USB capability and small size. However, with the introduction of the Raspberry Pi RP2040 micrcontroller in 2021, keyboards have begun to appear using it. Comparitively, it has a lot more processing power, memory, and peripherals. For this project I went with the Seeed Studio XIAO RP2040, as it is the smallest RP2040 board on the market. Seeed Studio were kind enough to sponsor this project, and I used their FusionPCB assembly service to create the finished, gorgeous PCBs. I can highly recommend them!”