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Hacking Digital Calipers

It’s tedious to write down digital caliper measurements while working with research samples since you have to set the calipers down each time to record the value.

Use SAM32 to read the caliper measurement, decode the protocol, and emulate keystrokes over USB to enter data into spreadsheet.
Note: wired design driven by @CaitlynBioE‘s specific use-case.

Choosing the Right Calipers

Enabling USB input from digital calipers is expensive: Amazon Mitutoyo USB Input Cable runs $174 on top of the already $150 calipers! But, it shows us there’s at least an interface to work with (on some models). You can see by the product image that the cable mates with a 4-pin press-fit connector on the body of the calipers.

Not all calipers will have output capability. In fact, after tearing down the most popular budget calipers on Amazon: iGaging IP54 Electronic Digital Caliper we see that the glob-topped IC driving the linear encoder doesn’t even have the data-output pins available for us to use.”

Link to article