If you want to reverse engineer a PC board, you could do worse than X-ray it. But thanks to [Philip Giacalone], you could just take a photo, load it into PCB Tracer, and annotate the images. You can ...

4-layer PCB (Altium) with isolated analog and digital domains. Professional audio I/O circuitry (simulated in LTSpice). USB connectivity. Firmware in STM32CubeIDE with FreeRTOS. CMSIS-DSP accelerated ...