This is a website for my hobby projects, usually involving electronics. Feel free to contact me or leave a comment if you like them.

BGA inspection using plastic prisms

Project from 20.4.2024 to 21.4.2024.

BGA (Ball Grid Array) packaging for microchips is getting more common as devices become smaller. It's quite feasible to solder with a basic home reflow setup, but verifying the results is difficult. The gold standard would be X-ray imaging, but short of that you can use optical verification with simple prism tools.

Relay multiplexer for lab instruments

Project from 27.2.2024 to 5.3.2024.

I have been adding programmable equipment to my home lab: USB connected power supply, electronic load, multimeter, oscilloscope and function generator. This is great for doing parameter sweeps and long term tests. But often I have more than one thing I want to measure with the multimeter. In this project I build a simple relay multiplexer for selecting signal sources.

Improved frequency reference for ELV FC-500

Project from 25.11.2023 to 28.11.2023.

As one of my first electronics projects, two decades ago I built a ELV FC-500 frequency counter out of a kit. It has worked great and found use in several projects where I have needed to check the accuracy of oscillators. I just wished for a bit more accuracy on the meter.

Custom built TEM cell for EMC measurements

Project from 11.10.2023 to 23.10.2023.

EMC tests are scary: often they are near the end of electronics development, and an extra prototype round can really mess up schedules. How nice would it be to check for obvious issues already in the first prototype?

Alphabet LEGO bricks

Project from 18.11.2022 to 10.12.2022.

LEGO bricks with alphabet are weirdly unavailable in the 1x1 size. There are DUPLO bricks and small round pieces with letters, but each with only one letter. Doing it that way needs a pretty big bunch of bricks to actually be able to spell something.

Custom-built CNC router

Project from 1.10.2021 to 25.6.2022.

Our local hackerspace had some linear motion units that were donated to us. After sitting in storage for a few years, it was time to make some use out of them. As a starting point I had a cabinet that I had built for a robot hand project, which I abandoned after figuring out that it just wasn't going to be particularly useful as a CNC router.

Automatic fume removal trigger for JBC soldering station

Project from 28.12.2021 to 29.12.2021.

I decided to upgrade from TS-100 soldering iron to JBC BT-2BWA. I used to have my TS-100 on the same switch as fume removal, but decided to make a more advanced automatic trigger for the JBC station.

Led lamp for kid's hat

Project from 7.10.2021 to 18.10.2021.

It's the dark season again, and time to plaster our child's clothing with reflectors and lights in an effort to increase safety. Hats with front lamps are a thing, and headlamps exist also, but neither seems to work that well for making a kid visible from any direction. So it was time to make my own.

Fixing noisy measurements on Owon XDM2041

Project from 15.6.2021 to 27.6.2021.

Needing some equipment for automatic testing, I ended up buying a Owon P4603 programmable power supply and Owon XDM2041 bench multimeter. The power supply has been mostly ok, but the multimeter always felt a bit noisy - especially in the 50 MΩ resistance range.

Voltage and current reference

Project from 14.2.2020 to 15.2.2020.

When developing a data acquisition system, I ran into a need of having fairly accurate current reference to compare against, 0.1% accuracy or better. This is not a particularly high standard, but unable to find a suitable device in my price range, I chose to design my own.

TARDIS - Bigger on the inside

Project from 15.11.2018 to 19.12.2018.

In the Doctor Who TV series, TARDIS is a time machine that looks likes a police box, and is bigger on the inside. A few months ago I saw a very cool implementation of this on Hackaday, and it was perfectly timed to remake one for Christmas.

ESP8266 walkie talkie

Project from 1.5.2018 to 3.6.2018.

I've been looking for a good two-way radio for bicycle trips, to be able to talk easily without needing to ride too closely. After trying out some smartphone apps and Leixen VV-108 mobile radio, I decided to build my own based on ESP8266. However, it didn't go quite as well as I hoped..

Magnetic toy car city

Project from 24.11.2017 to 21.12.2017.

A few years ago my sister mentioned a model train exhibit they'd seen, where cars moved on streets by themselves. I can only guess at the mechanism, but I think it might involve magnets. This project is a simple implementation of the concept - gears move magnets under the surface and cars follow them along a track.

Close-up lens for phone camera

Project from 9.4.2017 to 9.4.2017.

There is a simple solution to taking close-up images with a non-autofocus camera - it's called a close-up lens. It is a simple convex lens, and because the main imaging is done by the camera's own lens, it can be of quite poor quality and still work fine. Thus I was able to make one out of acrylic using my CNC3020.

Wooden animal puzzle

Project from 11.10.2015 to 6.12.2015.

A classic wooden animal puzzle, CNC routed and hand-painted. This was a Christmas present to my newest nephew, half a year old. As such, I had to take into account some safety aspects also.

EMF detecting wand

Project from 28.3.2015 to 3.4.2015.

My coworker has this nifty tool that he uses to check standby modes on various devices. It works by detecting electro-magnetic fields and converting that into sound. Seeing his stripboard design that he has carried with him for 10 years, I just had to clone it.

3D printer head for CNC 3020

Project from 9.11.2014 to 22.3.2015.

Having got my CNC router working decently, an obvious next step was to add a 3D printer head to it. As it already has all the mechanics needed for the 3-axis movement, I only needed to add an extruder and hotend to make it print.

Firewood trolley

Project from 20.9.2014 to 26.10.2014.

When you own some forest, firewood is a cheap way to warm a house. However, transporting them indoors can be dreary, and once indoors they'll reward the bearer with litter on the floor. This project is a trolley with big wheels for easy rolling and plastic walls to contain the chaff.

DSO Touch

Project started on 6.9.2014.

I received a DSO Touch as a free review sample from Seeed Studio. This is a review of it, from a DSO Quad owner's perspective.


Project from 7.6.2014 to 13.6.2014.

Eager to try out the CNC mill, I decided to make a pantograph as a present to my nephew. Pantograph is a device that uses four linked arms to constrain the movement of two pens. When one pen is traced over a shape, the other pen draws the same shape enlarged or miniaturized.

Silver cat necklace

Project from 28.2.2014 to 23.5.2014.

Shapeways nowadays offers 3D printing in sterling silver in quite competitive prices. A custom piece of jewellery will cost 50-100 EUR, not really more than what a similar product would in a store. Of course, there is both the benefit and the effort of having to design the model first, if you really want it to be unique..

A CNC router

Project started on 25.2.2014.

Having been a happy Dremel owner for more than a decade already, I am well aware of the joy in finding all kinds of objects hidden inside slabs of wood and plastic. Only problem is that it's somewhat imprecise to cut them out of their solid prison when operating the tool just by hand. To that end, I decided to buy a CNC mill/router.

Automatic dog collar light

Project from 14.10.2013 to 18.11.2013.

My parents live in the countryside, so they often let their dogs run free in the yard. The dark winter evenings tend to make the dogs quite invisible, which is both annoying when trying to call them back inside, and dangerous if they should roam towards the road. This is a light that can remain attached to the collar and turns on automatically when needed.

LED wakeup light

Project from 4.9.2013 to 30.9.2013.

Winter is coming again, and it tends to ruin my sleeping habits. I have previously used a store-bought wakeup light, but it has a bunch of problems, such as annoying alarm sound that cannot be turned off. For the new apartment, I made a much better wakeup light by changing the controller on some cheap RGB led strips bought from eBay.

Driving E-ink display

Project from 23.3.2013 to 25.9.2013.

E-ink displays, such as the ED060SC4-V2, are easily available off eBay. They are sold as spare parts for e-book readers, but there is nothing to stop you from using them in your own hobby projects. Or is there?

Dust box for Dremel

Project from 14.9.2013 to 21.9.2013.

A lot of things I make tend to involve carving large holes with Dremel. With proper cutting bits, it is a fast way to make custom enclosures for all kinds of projects. However, it does generate an awful lot of chips and dust. For years now, I have had small walls made of fiberboard around it to contain the dust; now I decided to make it a bit more presentable.

Spin plate for taking 360° photos

Project from 29.6.2013 to 18.7.2013.

This idea came from a three-phase brushless DC motor that I had disassembled from a broken hard drive. Having made enough persistence-of-vision displays for a lifetime, I needed some other use for the motor. Ergo, a spinning platform for taking 360° photos of things.

Juice decanting pipe

Project from 16.3.2013 to 16.3.2013.

Homemade juices tend to accumulate some dregs at the bottom of the bottle. When pouring out the juice, one always hopes that the sediment wouldn't follow.. but as air bubbles through the neck of the bottle, it stirs the liquid and lifts the solids from the bottom. My mother wished for a pipe that would let the air flow freely to avoid this.

Duck plate with OpenSCAD

Project from 18.11.2012 to 8.12.2012.

Inspired by the ceramic materials on Shapeways, I really wanted to make something with them. Actual ideas were more difficult to come up with, though.

Remote controlled sphere

Project from 9.4.2012 to 3.10.2012.

This is a remote controlled sphere, not unlike the sphero and several DIY variants. It served as a great opportunity to test out inertial sensors & RF control, as well as being a birthday present for my nephew.

Wire-suspended "delta robot"

Project from 2.7.2012 to 3.8.2012.

My summer job this year involved the selection of 3D coordinates by mouse from a stereo image pair. To demonstrate the results, I built a cheap robot that picks up the selected object.

Flowers that open with Flexinol wire

Project from 27.4.2012 to 4.5.2012.

For our Demola project, we needed a tree with flowers that open by electronic control. The purpose was just to illustrate the concept of a physical tree that would react to energy saving and other good deeds.


Project from 5.1.2011 to 1.12.2011.

This was an attempt to build a remotely operated robot boat. It was planned to have a STM32 processor, GPRS link, GPS and solar panels, in a body about 50 cm long.

DSO Quad

Project started on 24.10.2011.

My DSO Quad arrived last week and I've found this little device excellent. While the analog bandwidth is a bit limiting, it is an amazing deal for the price, and best of all, it is fully open source!

Broken thermometer = window paintings

Project from 18.7.2011 to 18.7.2011.

Our thermometer broke. Surprisingly, they still contain liquid metal even though it is not toxic mercury anymore. I forgot about the whole incident, until I spotted a little drop of the metal clung to the back of a chair.

Big wheels

Project from 1.9.2010 to 12.4.2011.

I did my civil service at a local museum. As a side project, I was assigned to "create something that demonstrates how mechanical power transfer works" for the steam engine room. This is what I came up with.

Make a faux product description sheet

Project from 22.12.2010 to 22.12.2010.

Add a little bit of obscurity to your self-made christmas present. A fake Chinese setup guide sheet might have your friend confused for a moment, not knowing if the present actually is self-made or just of really crappy (or excellent!) Chinese quality.

Plywood gears

Project from 18.11.2010 to 20.12.2010.

This is a technical gift to my nephew: plywood planetary gears. I had the opportunity to order some water jet cut parts for a work project, and after seeing the results I tried it in a hobby project also.

Headphone attenuator

Project from 27.11.2010 to 28.11.2010.

My new Nokia 2710 has a radio. However, the sound is way too loud, even with the headphones that came with the phone. It's also not the only device with this problem: often the volume control doesn't go low enough so that you can listen comfortably in a silent room.

A juicebox holder

Project from 25.9.2010 to 26.9.2010.

Small juiceboxes have one flaw: squeeze too hard and the juice shoots out. That very much annoys my sister (and does not annoy my 2-year-old nephew nearly as much), but my father thought about a simple solution: plastic box that is strong enough to stand a firm grip.

DIY Garmin GPS bike mount

Project from 24.9.2010 to 25.9.2010.

I recently bought a GPS-receiver, Garmin eTrex Legend HCx, mostly for bicycle trips and for improving OpenStreetMap. However, from what I've heard, Garmin's own bike mounts are not only expensive but also weak. Therefore I decided to make my own.

SMD probe for multimeter

Project from 7.8.2010 to 8.8.2010.

While fixing my laptop, I needed to probe several pins on a surface mounted chip while the system was running. Obviously I didn't want to short-circuit anything by accident.

How to fix a matrix keyboard

Project from 28.6.2010 to 12.7.2010.

My workplace had a Brother label printer with broken keyboard. This isn't an ordinary consumer model; instead, it prints on 30 mm high tape and costs several hundred EUR. Therefore it was actually worth fixing, unlike some cheaper models.

Toy car for my nephew

Project from 27.4.2010 to 13.6.2010.

A robotic car may be a bit advanced for a two-year-old, but it is what I did anyway. This car can drive forward and backward, steer and detect obstacles and has working lights.

Tiny brass figures

Project from 23.10.2009 to 14.2.2010.

These tiny figures are carved from 4 mm brass, the same material I used in the toy car. The tools required are just Dremel (or any other miniature drill and bits), an utility knife, some files, and a hacksaw.

4 pictures in a cube

Project from 29.11.2009 to 19.12.2009.

This cube is supposed to be cute. When shaken, it randomly displays one of four pictures, which are carved on pieces of polycarbonate.