Custom Interface Adds USB And Wi-Fi To Digital Calipers

Although previous-college machinists typically desire the mechanical vernier scale on their trusty calipers, a lot of end users nowadays acquire calipers with a electronic readout. These models usually occur with more functions like differential measurements, or a “hold” operate for those circumstances where you have to maneuver the instrument someplace deep within a equipment. Yet another practical aspect is a details connection that allows you log your measurements on a pc directly rather of manually getting into all the values.

The VINCA-branded caliper that [Liba2k] acquired has these kinds of a data hyperlink characteristic, which calls for a USB adapter that’s marketed individually. There is a micro-USB connector on the device alone, but instead of employing a USB interface, this is utilised to carry a proprietary serial protocol — a style and design conclusion that should to be labeled as a felony if you ask us. Instead than shopping for the formal USB adapter, [Liba2k] decoded the protocol and crafted his individual interface identified as VINCA Reader that can connect by means of possibly USB or Wi-Fi.

The serial structure turned out to be a basic serial bus that clocks out 24 bits at a time. In order to adapt its 1.2 V signal degree to the 3.3 V applied by an ESP32, [Liba2k] made a simple stage shifter circuit utilizing a handful of discrete factors. The ESP can talk with the pc by means of its Wi-Fi interface, for which [Liba2k] wrote a spreadsheet-like software alternatively, an ordinary USB cable can be linked to emulate a keyboard for use with any other application.

With its added Wi-Fi characteristic, the VINCA Reader is really additional finish than the official USB adapter, and will almost certainly be much less expensive as perfectly. The serial interface seems to be widespread to all caliper makers, though quite a few went for a far more sensible connector than micro-USB. An automatic readout technique is significantly useful if you have to make 1000’s of very similar measurements.