closed loop firmware
@zfredin and @gils the firmware you seek for closed loop control is here: https://gitlab.cba.mit.edu/jakeread/ucbus-stepper/-/tree/master/firmware/cl-step-controller
this should run, for one motor connected over USB, using this javascript / browser tool: https://gitlab.cba.mit.edu/jakeread/ucbus-stepper/-/tree/master/controller - the tool will give you control over PID settings, etc ...