Hi All,

I was wanting to build a Torch Height Sensing using a phototransistor with index pulse board - http://www.cnc4pc.com/Index_Pulse_Card.htm, hopefully that it could provide some values feeded back to Mach3 so that it can control the Z Axis Motor. Lets say em, bigger the value , the motor goes down more, and vice versa. What do I need to know to build this?