Finished my fourth board in as many weeks, finishing off the bare minimum of boards I need to get the CNC mill back up and running.

This board mounts inside the machine itself, and connects via a cable back to the main PCB in the control. This board connects via screw terminals to the various homing and index sensors inside the mill, provides a little bit of signal conditioning, and converts to differential signalling for transmission over a long cable run near noisy stepper drive cables.

I expect this will not be the last board I do for the conversion, since there are other projects to tackle like the control pendant and spindle index sensor, but these four boards should at least allow me to get the mill back up and running, using my fancy new FPGA driver board, and with proper emergency stop capability!  It’ll be nice to tidy up the wiring and finally bolt down the components inside of the control box as well.