hi all

I’m after a bit of help. I’ve made a combined edge probe and touch plate for my cnc. Connected the positive to the plate and negative to my spindle. The positive is connected to port a5 on my Arduino Uno and ground to the ground pin. But no matter what I do, I can’t seam to get the probe to work, is there something I’ve missed as apart from how to use the probe, I can’t seam to find any tutorials on how to set it up.

I’ve checked the continuity on the wiring and all if fine, but just won’t work then the tool touches the plate

Hope someone can help with this