AndyUK's Build - 1.2x1.0m Gantry

[AndyUK]

Managed to reprogram one of the drives last night (its a faff now they're in the cab) to be Enable Active low, and instantly was able to get my first self-powered movements on that axis (huzzah!! - I'll post a video once I have all three axis working and this enable issue resolved, because as usual the garage is a tip).

I didn't change the enable wiring, and noticed that the drive was enabled whatever happened (one of the other unconnected drives faulted out which dropped the OSSD output, but it had no effect on the active low drive). Therefore, the problem isn't that I've got my logic states messed up, or at least that's not exclusively the problem.

My next step is to try experimenting with wiring setups to try and get the enable functioning. First I'm going to try Vsarak's two suggestions above, first utilising the 5V rail and another output (schematic B), and second, using a differential connection from a spare axis output (schematic A).

The third step would be to try the NPN connection recommendation in the EM806 manual (which I now realise is effectively what I've been trying to do). The only difference here is that the resistors are placed on the ENABLE - line rather than the ENABLE + line - would that really make a big difference? See attached.