The word clock on a desk, with "tien", "over", "half" and "twaalf" lit

An Impeccably Documented Word Clock In Dutch

[Maarten Pennings] shares a word clock project – but not the regular kind. For a start, this clock is a shining demonstration of hobbyist-available 3D printing technologies, with embedded light guides for the letters printed in transparent filament, thanks to a dual-extruder printer. For a word clock, it’s surprisingly small – in fact, it uses an 8×8 addressable LED matrix, with words shown in different colors. If you’re looking to build a novel word clock, you’re all set here – [Maarten] tells all about this project’s story and provides a treasure trove of insights into designing all of its aspects!

The 8×8 limitation was initially set because he wanted to use a low-cost MAX7219 8×8 LED matrix module as a base for the clock. Thankfully, in Dutch, time can be expressed using shorter words — still, it had to be limited to 5-minute intervals. Extra effort had to be spent designing the layout — [Maarten] mentions his friend writing a solver that found a way to fit some words onto the layout diagonally. At some point, he switched from LEDs to Neopixels, and dug deep into addressable LED technology. For instance, he demonstrates Neopixel power measurements and current consumption calculations. This shows that the calculations indeed match the clock’s real consumption when measured by an external meter.

In the best of hacker traditions, all the source files are on Github — if you fancy yourself a Dutch word clock, you can build [Maarten]’s design easily! He provides extensive instructions on building this clock in the README, including a flashing and configuration tutorial, complete wiring diagrams, and a soldering guide. A manufacturing-grade amount of build information that won’t leave you guessing. He’s also added a fair number of animations, put plenty of effort into clock precision verification, and even investigated some Neopixel protocol minutiae. All in all, our hacker went all in on the capabilities while embracing the constraints. This reminds us of the similarly well-documented haptic word clock we covered just a year ago – check that one out, too!

Continue reading “An Impeccably Documented Word Clock In Dutch”

Heating A Home With Sunlight… And Water

The sun is a tremendous source of energy, and while photovoltaic panels are an easy way to harvest some of that energy especially now that prices for them are incredibly low, there are plenty of other ways to tap into that free energy as well. [Engelbert] was looking for alternative ways to heat his house since traditional methods were prohibitively expensive, and ended up building a heat exchanger using solar-heated water to cover his home heating needs. (Google Translate from Dutch)

The system uses several large roof-mounted hot water heating panels. The heat captured by them is then pumped into an underground pipe network which is able to warm up a large area of earth in the summer. In the winter, that heat is able to be extracted back out of the earth and used to heat his home. The system includes almost three kilometers of pipe which are buried two meters below grade, so this will probably not be a weekend project, but it still cost much less than the €80,000 to install gas heating in his home.

[Engelbert] is able to use this self-built system to keep his home and another smaller building at a constant 23°C all year. He actually overbuilt the system slightly and has since disconnected almost half of the pipes, but we certainly understand the desire to over-engineer things around here. The only problem he has had is with various government entities that are slow to adopt energy-efficient systems like these. Perhaps the Dutch government can take some notes from the Swiss when it comes to installing geothermal systems like these.

Thanks to [Jero] for the tip!

Mark Hoekstra Has Passed Away

UPDATE: His personal site has been updated.

It was with great sadness that we learned of [Mark Hoekstra]’s death this morning. Earlier this week, the 34 year old hacker suffered a heart attack while riding his bicycle and was admitted to the hospital in a coma. [Markie] has been a Hack a Day commenter for much of our existence and a project contributor for nearly as long. It started simply with things like his bright green Hack a Day iPod sock and a hand crank iPod charger. He did an excellent job documenting his projects; many people had built IR cameras, but none were nearly as thorough as him. He also enjoyed sharing his love for obsolete hardware with the community. He built a wireless eMate, turned two Mac SE/30’s into audio viualizers, and wired shutter glasses to an old SGI.

It was always a treat to hear about [Mark]’s latest project and he’ll be missed greatly.

[photo: Bram Belloni]