2 layers61.8 × 21.6 mm

USBQuadMouse
PR77/CH554_USBQuadMouseKeyboard
CH554 based USB to Quadrature Mouse and Keyboard Interface
24 parts8MIT
KiCad boards from 2 GitHub repositories tagged “ch554”, the most starred first; open any of them in PCBKit.

PR77/CH554_USBQuadMouseKeyboard
CH554 based USB to Quadrature Mouse and Keyboard Interface
