This might be useful for accurate position sensing in home made / hacked computer aided manufacture systems. Adds USB functionality to your callipers.
A great reference on reading digital callipers can be found at:
What this instructable adds to the shumatech tutorial is:
How to use an Arduino to read the callipers (using very few extra components).
Details of another protocol found to be in use on some callipers.
Basic Arduino code is provided.
To see more of my work please visit j44industries.
Step 1: The Callipers
After some experimenting with a multi meter and a jyetech oscilloscope (a very cheap basic oscilloscope that can be bought in kit form for under £40) I found the pins to be as shown in the diagram.