Custom Interface Adds USB And Wi-Fi To Digital Calipers

Despite the fact that aged-faculty machinists commonly choose the mechanical vernier scale on their trusty calipers, quite a few customers presently invest in calipers with a electronic readout. These products often arrive with extra attributes like differential measurements, or a “hold” operate for these scenarios where by you have to maneuver the instrument someplace deep inside a device. Another helpful function is a data website link that allows you log your measurements on a computer straight as a substitute of manually moving into all the values.

The VINCA-branded caliper that [Liba2k] acquired has these a knowledge connection characteristic, which involves a USB adapter that’s sold separately. There is a micro-USB connector on the software itself, but as an alternative of applying a USB interface, this is employed to carry a proprietary serial protocol — a layout determination that ought to be categorised as a felony if you request us. Rather than buying the formal USB adapter, [Liba2k] decoded the protocol and developed his possess interface referred to as VINCA Reader that can join by way of either USB or Wi-Fi.

The serial format turned out to be a very simple serial bus that clocks out 24 bits at a time. In order to adapt its 1.2 V sign degree to the 3.3 V used by an ESP32, [Liba2k] designed a very simple level shifter circuit using a handful of discrete elements. The ESP can communicate with the pc by way 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 software program.

With its added Wi-Fi feature, the VINCA Reader is actually extra entire than the formal USB adapter, and will likely be more affordable as properly. The serial interface seems to be widespread to all caliper producers, while several went for a additional wise connector than micro-USB. An automated readout program is notably handy if you have to make 1000’s of similar measurements.