Tag: HW

Old meter (MXD-4660A), new tricks.

I pulled my veteran DMM, a Voltcraft MXD-4660A, from the drawer to set up my workbench (adding a serial-to-USB converter) and gave it a second tour of duty with QtDMM on Ubuntu. After a bit of searching online what to use under I found the QtDMM project at http://www.mtoussaint.de/qtdmm.htmlm , but appears abandoned. The active fork, I think, is at https://github.com/tuxmaster/QtDMM.

Here’s the final install and setup for my lab computer running Ubuntu 22.04 (Jammy):

Build & Install QtDMM on Ubuntu 22.04 (Jammy)

1) Prerequisites

  • Enable Universe and base tools:

    sudo apt update
sudo apt install -y software-properties-common
sudo add-apt-repository -y universe
sudo apt update

  • Compilers, build tools, VCS:

    sudo apt install -y git build-essential cmake ninja-build pkg-config

  • Qt6 SDK

    sudo apt install -y qt6-base-dev qt6-tools-dev qt6-tools-dev-tools qt6-l10n-tools libqt6serialport6-dev

  • HID API

    sudo apt install -y libhidapi-dev libhidapi-hidraw0

  • OpenGL headers for Qt6Gui/Widgets

    sudo apt install -y libopengl-dev libgl1-mesa-dev libglu1-mesa-dev mesa-common-dev

  • Serial access without sudo:

    sudo usermod -aG dialout "$USER"

  • Log out and back in to apply group membership

2) Get the source and make the script executable

git clone https://github.com/tuxmaster/QtDMM.git
cd QtDMM
chmod +x compile.sh

3) Build

  • Clean build (optional). Also verifies prerequisites are present. 
    ./compile.sh clean || true
rm -rf build CMakeCache.txt CMakeFiles
./compile.sh
  • Artifacts land in ./bin/: 
    ./bin/qtdmm --version
  • Verify it runs. If not, see Troubleshooting below

4) Install for all users (see §5 for a .deboption)

Preferred:

sudo ./compile.sh install
# now on PATH:
qtdmm --version

5) Alternative: make a .deb

Keeps your system clean and is easy to remove later.

./compile.sh pack
sudo apt install ./QtDMM_*amd64.deb

6) Uninstall

If installed via .deb:

sudo apt remove qtdmm

If installed via compile.sh install:

# run from the same build dir used for the install
sudo xargs rm < build/install_manifest.txt

Troubleshooting:

If you hit errors, try a clean build reset instead of first searching forums. I learned the hard way to make a clean install as a belt-and-suspenders reset, that deletes built objects but keeps the CMake cache.

  • “|| true” lets the sequence continue even if the clean step fails due to a broken config.
  • “rm -rf build CMakeCache.txt CMakeFiles” force-removes any stale out-of-source build dir and any accidental in-source CMake cache:
  • “Final ./compile.sh” does a fresh configure and build: 
cd ~/QtDMM
./compile.sh clean || true
rm -rf build CMakeCache.txt CMakeFiles
./compile.sh

Let’s check if it’s running

  • As your regular user, start QtDMM from the command line or via the Ubuntu Dock (search for “QtDMM”):
  • Hint: How to create a Desktop shortcut launcher for ubuntu 22.04
    QtDMM - Running

  • Configure settings for MXD-4660A:
    Setup Voltcraft MXD-4660A

    Final test setup (send a known signal) and the result: MXD getting some imput from generator to prove reading
    QtDMM running, getting Data


Question to readers: Is there Linux software for the old Hameg HM1507-3? I’m currently using a Windows XP VM with very old software.

“Hello World” Project for Tōgō Lab: FireFly Morse Blinker

This is my first hardware project on the new ToGo-Lab.io server.

Some years ago, when I started with AVR/ATTiny programming, I built a tiny Morse “throwie”: one ATtiny, one LED, one resistor, and power-friendly firmware. The goal was to use as few parts as possible to keep it cheap, while still adding a couple of useful functions.

Two main functions: Detect daylight. If it’s bright, sleep; if it’s dark, send a Morse message. The LED doubles as a light sensor.

This is a good restart for my new project home, https://togo-lab.io/, the HW version of a “Hello World” program. So I don’t plan heavy hardware work here, though I may add a small solar cell to stretch battery life. This version adds a supercapacitor and small solar cells and uses the LED as a light detector, so it only blinks in the dark. It’s no longer a throwie, more of a pendant. Hang it where it gets daylight and stays dry. It charges by day and blinks by night.

Yes – I want also a PCB and maybe you will the final result as a little DIY Project on e.g. – Tindie.

But real goal is to define the specs and a simple, repeatable workflow from Idea to real DIY Kit especially for bigger future projects.

This post will evolve as the project advances. I’ll append notes, design decisions, and lessons learned rather than writing a single post-mortem at the end. But don’t expect too much progress too quickly; this is a side hustle. Perhaps in a few years, after I retire, it will become one of my main activities.

What it is

  • DIY-Kit goal: beginner-friendly soldering kit with clear docs and hackable programm (using Arduino IDE).
  • MCU: ATtiny45/85, through-hole.
  • Power: 3–5 V, with solar + supercap option.
  • Behavior: Morse message presets, LED as light sensor for night-only blink.

Process and tooling

Roadmap

  • v0.1: Proto: breadboard + first PCB, single message, speed presets.
  • v1.0: Pilot: build guide, BOM with alternates, pilot of 10 units.
  • v1.1: docs polish, optional brightness setting, minor PCB tweaks.
  • v2.0: Zero Series
  • …

How this post will evolve
I’ll update this page with:

  • Schematics, Circuit description,
  • PCB Design, CAD. All you need to build one,
  • Build photos and assembly hints.,
  • BOM changes and sourcing notes,
  • Additional Blog post about the program itself and how to do with Arduino IDE.

Want to get involved?
Suggestions welcome. Open an issue on the repo or email tgohle@togo-lab.io. If you build one, share photos and your timing results—those will feed back into the docs and the next revision.

Schematics, Circuit description,
tbd