I have just bought a 3 wire (5v, ground, signal) touch probe, which I plan to connect to a free pin on my CNC breakout board. I want to configure the probe to find the edge in X and Y of my workpiece or my workpiece holder (back left as you look into the machine). Can anyone recommend and post a simple script to me?

Most 3 wire probes are normally open when they touch the material, the signal pin is pulled low or high depending on your board.

Before using any script, first make sure the probe input changes state correctly when touching metal. Most problems usually come from inverted signal settings.