Bluetooth extension for cheap digital calipers. An ESP32 reads data from the caliper serial port and "types" it as a BLE keyboard directly into the host computer.
The caliper-reading functions have been condensed into a simple class Calipers inside the file Calipers.h. You can use the library as a standalone library for any Arduino (not only ESP32).
There are different scales and calipers out there with different protocols. See the readme of the library for more information.