New guy finishing off a mini mill build

[Doddy]

I've come across this from another site...



Yeah, you can short VDD to +5V - that will allow you to run on a single PSU. You don't get analogue spindle control (but neither does your other board, and I don't think you're yet set up for it). The '817 opto devices are slow, so you might not get the optimal throughput through the Opto-coupled outputs (as I say... you can get "too" isolated :) ) so keep your drivers at x8 to keep your feed rates up. The slow behaviour on the inputs is largely irrelevant.

If you wanted to go to proximity sensors on limits then you might need to decouple and raise VDD to about 8-12V. The higher you go, the more you may need to add additional resistors on the stepper-driver interface, and on the input terminals. Best to try for now at 5V and bridge 5V/VDD, using microswitches for limits.