Even though old-school machinists ordinarily desire the mechanical vernier scale on their trusty calipers, numerous customers currently invest in calipers with a digital readout. These models generally appear with extra features like differential measurements, or a “hold” function for all those circumstances where by you have to maneuver the instrument someplace deep within a device. A different helpful function is a info backlink that allows you log your measurements on a laptop or computer specifically instead of manually moving into all the values.
The VINCA-branded caliper that [Liba2k] bought has these a info hyperlink aspect, which needs a USB adapter which is bought separately. There is a micro-USB connector on the resource by itself, but rather of applying a USB interface, this is utilised to have a proprietary serial protocol — a structure decision that should to be labeled as a felony if you ask us. Instead than acquiring the official USB adapter, [Liba2k] decoded the protocol and crafted his individual interface known as VINCA Reader that can hook up by way of either USB or Wi-Fi.
The serial structure turned out to be a easy serial bus that clocks out 24 bits at a time. In order to adapt its 1.2 V signal stage to the 3.3 V made use of by an ESP32, [Liba2k] created a simple level shifter circuit using a handful of discrete parts. The ESP can talk with the laptop or computer as a result of its Wi-Fi interface, for which [Liba2k] wrote a spreadsheet-like application alternatively, an standard USB cable can be linked to emulate a keyboard for use with any other program.
With its additional Wi-Fi function, the VINCA Reader is basically more finish than the formal USB adapter, and will almost certainly be much less expensive as properly. The serial interface appears to be common to all caliper producers, while numerous went for a additional reasonable connector than micro-USB. An automated readout system is significantly useful if you have to make hundreds of comparable measurements.