Wanting to investigate a slightly Heath-Robinson idea to improve my CNC work setup process, I grabbed a digital dial guage (0-25.4mm) for probing things... The device had a cable option which I initially skipped, but the connector was a pain and rather than destroy my device to solder in a socket I bought the cable (for £1.99+tax).

It's supposedly 1.37volt logic, but the cable converts to RS232, and they included a USB-RS232 adapter. The device and cable came with 2x 8cm Compact-Discs (CDs) for software drivers and official software. I do actually still have a DVD/CD combo drive in one laptop, but forget about that. The instructions showed it in Chinese and windows only, and I plan to use a Raspberry Pi, so I went straight to an LLM to make a prototype web-serial demo.

Claude started the project, then I moved to claude-code in the hope claude would read the serial output too, but I/it got distracted with it nearly working for ages. In the end claude-code took it down an alley of insanity, and I switched to vscode in Agent mode to start afresh at the same time. VsCode sorted it right out first time. Then a quick correction for the initial boot messages received, and finally glam it up a bit along with adding scaling to the dial. Of course to use it with the Pi it would need converting to python/node, so I did that and tested via WSL.

Source Code / Readme etc: 

https://github.com/tyeth/digital-dial-gauge-web-serial

Interactive Webpage:

https://tyeth.github.io/digital-dial-gauge-web-serial/

Live embedded iframe/oEmbed version:

So that's one less hurdle to getting my ultimate CNC setup going, along with some future shenanigans...

Keywords for future search ninjas:

Dial guage, guage, gauge, dial gauge, digital dial guage, digital dial gauge. Read gauge over serial at 9600

Readme from Project:

Digital Dial Gauge Serial Logger

This project provides scripts for reading and parsing digital dial gauge data from a serial port, in both Python and Node.js. It is useful for logging, automation, and integration with other tools.

There is also a web-serial version (no installation - only a Chrome based browser needed):

https://tyeth.github.io/digital-dial-gauge-web-serial/

Features

• Reads data from a digital dial gauge via serial port
• Parses and logs values in millimeters
• Supports reading a single value, multiple values, or continuous logging
• Timeout option to avoid waiting forever
• Usable as a CLI tool or as an importable module (Python and Node.js)

Python Usage

As a CLI tool

python3 serial-gauge-log.py /dev/ttyUSB0 --count 5 --timeout 3

• --count N: Number of values to read before exiting (0 = infinite)
• --timeout SECONDS: Timeout in seconds (0 = no timeout)

Example output:

[RESULT] [(12.345, '12.345'), (12.346, '12.346'), ...]

As a module

from serial_gauge_log import get_gauge_values
values = get_gauge_values('/dev/ttyUSB0', count=5, timeout=3)
print(values)

Node.js Usage

As a CLI tool

node serial-gauge-log.js /dev/ttyUSB0 --count 5 --timeout 3

• --count N: Number of values to read before exiting (0 = infinite)
• --timeout SECONDS: Timeout in seconds (0 = no timeout)

Example output:

[RESULT] [[12.345,"12.345"], [12.346,"12.346"], ...]

As a module

const { getGaugeValues } = require('./serial-gauge-log.js');
getGaugeValues({ portPath: '/dev/ttyUSB0', count: 5, timeout: 3 }).then(values => {
  console.log(values);
});

Requirements

• Python 3 with pyserial (pip install pyserial)
• Node.js with serialport (npm install serialport)

Notes

• Adjust EXPECTED_DIGIT_LENGTH in the scripts if your gauge sends a different number of digits.
• Both scripts log raw and parsed data for debugging.
• The scripts are designed for easy extension and integration.

License

MIT License