Digimatic USB-Adaptor

Read out Mitutoyo measuring instruments via USB.

Tested with ID-SX2 indicator.

Usage

The adaptor presents itself as a serial device to the computer. Any input (e.g. newline) requests a measurement. The measured value is output as a decimal number with . (dot) separator in the unit of measurement of the instrument, followed by a newline. Errors are reported on lines starting with # (hash).

Wiring

A wiring diagram can be found here.

The DATA and CK signals are connected directly to GPIOs. The REQ signal is switched to ground with a NPN transistor.

The connector of the Digimatic data cables fits Molex 70246 series or 2.54 mm headers. Looking at the connector of the cable face-on with the key up, pos. 1 is top left and pos. 2 is below, bottom left.

Build

The Pico C SDK and TinyUSB are required and included as Git submodules. Git submodules may need to be initialized after a clone:

git submodule update --init --recursive

Build with CMake:

mkdir src/build
cd src/build
cmake ..
make

## Flash binary by copying via USB
# cp digimatic.uf2 ~/media/RPI-RP2
## OR flash binary with OpenOCD
# openocd -f interface/cmsis-dap.cfg -f target/rp2040.cfg -c "adapter speed 5000" -c "program digimatic.elf verify reset exit"

References

• https://forum.arduino.cc/t/mitutoyo-digimatic-spc/78312 and https://github.com/Roger-random/mitutoyo for a general understanding of the protocol and interface.
• Mitutoyo manual no. 99MAH059D1 for technical description and connector pinout.