Someone got DOOM running on a $30 multimeter, and it even has save slots
A $30 FNIRSI multimeter now runs DOOM's Freedoom equivalent in colour, complete with levels, saves and a drone controller.
Most multimeters are bought to check circuits. One of them is now doing something far less expected: running a version of DOOM in full colour on a device that normally lives in a toolbox.
The gadget at the centre of it is a $30 FNIRSI DMC-100, described as a multimeter, or a clamp meter depending on where you are. Instead of sticking to electrical readings, it has been turned into a handheld DOOM machine by Artur Bieniek.
That alone would be enough to earn a place in the long tradition of DOOM appearing on hardware nobody planned for. But this one stands out because the host device is such a practical bit of kit. A multimeter is supposed to measure current across a circuit. It is not supposed to load up a classic shooter.
A meter that now plays through an entire episode
In the clip below, the unlikely device is shown running the game.
The project works by getting the doomgeneric engine running on the Artery AT32F415 chip inside the DMC-100. From there, the meter is able to play Episode 1 of Freedoom: Phase 1, with the original E1M1 through E1M9 levels available.
It is not just a rough proof of concept, either. The build includes four save slots, and the surrounding parts of the game are there too, including the title screen, intermissions and the finale. It all runs in colour.
One of the strangest details is the control setup. Bieniek is not using the multimeter as a self-contained gamepad. The game is being controlled with a controller from a DJI drone. For anyone who wants the same setup, an RC-N1 is listed as optional.
The part that makes it even more ridiculous
What really pushes the project from a fun stunt into a proper tinkering challenge is the setup list. Anyone hoping to copy it needs a FNIRSI DMC-100 and a USB-C cable connected to a computer. Linux was used throughout, although any system able to copy files to a USB drive should work.
The build notes go much deeper than that. They call for GNU make 4.3 or newer, clang and ld.lld 20 or newer, several LLVM tools, Python 3 and git. The first build also needs certificates and network access. There is even a warning that clang 19 or older will not fit the firmware on the device.
The instructions also mention extra tools for tests, optional device checks and Renode support, plus one particularly unforgiving rule: the checkout path must not contain spaces.
So yes, it is possible to turn a bargain multimeter into a pocket-sized portal for Freedoom. The funniest part may be that the software side is demanding enough to make the actual hardware sound like the easy bit.
Why a multimeter can run a game at all
A multimeter is mainly a tool for checking electrical basics such as voltage, current, resistance and continuity. Even simple models often contain more computing power than their plain screen suggests. Inside, there is usually a small processor, memory, buttons, a display controller and software that interprets readings and draws menus.
That matters because a game does not care whether a chip was sold for entertainment or for test equipment. If the processor can run custom code, and the screen can show enough pixels, hobbyists can sometimes make the device do something far beyond its intended job. The result is usually slow, low resolution and awkward to control, but still impressive because the hardware was never designed for gaming.
Why Doom turns up on unusual gadgets
Doom has become the go to example for unusual game ports because it is old enough to be relatively lightweight by modern standards, yet still recognisable and interactive. Parts of its engine have been publicly available for a long time, so programmers can adapt it to many kinds of hardware.
Getting it running usually means building a stripped down version that talks directly to the device screen, buttons and storage. Sound may be removed, controls may be remapped and performance may be reduced. Save slots are not mysterious. If a gadget has writable memory, a memory card or some spare internal storage, software can often save progress there just like a normal game would, provided the programmer has added that feature.
What to know before trying similar mods
If you like this kind of project, the key question is not just, can it run a game, but should it. Test gear exists to be reliable and safe. A modified multimeter should not be trusted for serious electrical work unless it has been fully restored and checked. Many people keep hobby devices and safety equipment separate for that reason.
Before buying any meter for real use, focus on clear instructions, safe probe leads, the ranges you actually need, and a display you can read easily. If you want to experiment, look for devices with an active tinkering community, available teardown guides and a way to recover the original firmware. Always remove batteries or disconnect power before opening anything, and avoid experimenting on equipment used with household mains.
