Hi!

I’m a newcomer to CAD/CAM and this forum. My interest is to produce PCB for hobby/research use. I have two questions:

1. Do anybody know anything about on how to interface the iGaging “Snap Depth” Mini Depth Gauge Digital indicator (iGaging Snap Gauge), see below.

I have read the very good article at 21 Bit Protocol Scales, shumatech.com.
Even if the circuit layout of this particular device not is equivalent to the one in the article I suspect that the principally uses the same IC and therefore protocol solution. However of the four interface pins one is connected to ground (battery minus).

I expected at least one of the remaining pins would give the VCC voltage (battery voltage). But I cannot detect any voltage at all. It doesn’t matter how I measure between the pins all have a voltage of zero (measured with hi Z DM). I understand that I probably need an external clock. But on witch of the remaining three pins?

Another question is how high the clock frequency can go. The article mentioned 9 KHz, but the Chinese regularly goes up to 90 KHz and above! So if anybody has any information on this I would be grateful.

2. The other question I have is about ATC (Automatic Tool Change). I would like to incorporate that in my CNC miller. The most troublesome part is where to get or how to construct the chuck and still get the accuracy (run out) needed for PCB milling. Anybody that can give me some links or point me in any direction?

Regards

Bo, SM6FIE