USB HID interface for digital calipers. Mine is INSIZE 1108-200. It has micro USB connector, but the communication isn't USB at all. It's 24 bit synchronous serial protocol, which is commonly associated with cheap Chinese calipers.
Firmware for STM32F103 MCU.
PC program sending HID command to the MCU.
Unexpected difficulties with Windows HID keyboard policy preventing usage on this platform. The device behaves as a keyboard which can accept "output HID report" as well. Unfortunately Windows do not allow doing that. Unfortunately again, I failed to find a solution for that problem within one week, so I'm leaving it for future opensource magic, when someone send me a merge request which I'll happily accept.
Description of the modification of the Chinese st-link clone PCB. Not a complete guide how to do it.