Babar,

The cost of making your own digital calipers with the reliability and repeatability and the accuracy and resolution that you require, would be prohibitive.
Not to mention how are you going to calibrate them ?
Do you have adequate metrology standards to ensure that the measurement that you are making is accurate?
I have used Mitutoyo digital calipers and height gages in my work. They both have serial output. You can get the specifications to interface to the serial output from Mitutoyo. The outputs are logic level, not RS-232 levels. If you choose not to make your own interface there is one company that I have used that makes an inexpensive interface.


I used this cable on one of my projects to interface to a Mitutoyo digital height gage.
ASD - Gage Interfaces



Jacob