I built a custom 4-key macropad using a Seeed Studio XIAO RP2040. The project involved designing a PCB in KiCad, creating a 3D-printed case in Fusion 360, assembling and soldering the hardware, and programming it with QMK firmware. The most challenging part was learning PCB design and setting up the firmware correctly. I am proud of successfully completing the entire design-to-build process. To test the project, connect it via USB-C and use VIA to verify and customize the key mappings.