I designed a mainboard for a CNC machine using grblHAL.
The PCB was built for a specific machine and enclosure. For example, there is a secondary MCU (STM32G030) for handling the IO front panel, which is specific to the enclosure.
Features (clockwise):
- optoisolated USB
- Integrated DC-DC to get 5V, 3.3V, 10V from 12-28V
- Specific front panel connector
- Semaphore connectivity - safety feature, and to show at a glance if a job finished. Discrete mosfet open-drain output
- IO - 6 endstop inputs, Safety door, Abort, Feed hold, Cycle start, Probe, 4x GPIO, 2x Coolant
- Spindle connectivity - PWM or 0-10V. Modbus connectivity is prepared, not tested
- 6 motor outputs - usually used as XYYZ with 2 spares
- Fan connectivity for control box cooling
- F-RAM to log machine activity
PCB was manufactured and assembled by JLCPCB.