Desktop Soundbar Is Ideal For PC Use

April 13, 2022 by 17 Comments

Soundbars are a rather strange category of speaker, most typically used with televisions to add some punch that the drivers crammed into a flatscreen TV simply can’t match. [Matt] of DIY Perks wanted a soundbar that was better suited to use on a computer desk rather than in a loungeroom, and set about creating one.

Regular soundbars aren’t great for a computer desk as they tend to deliver sound directed at one’s chest rather than one’s ears. [Matt]’s design instead angles its speakers slightly upwards, aimed at the user’s head as it should be. The build uses reclaimed wooden flooring for a cheap source of pretty wood that isn’t as ugly or flaky as MDF.

The design acts as a monitor stand and keyboard hutch, raising the screen to a comfortable height for viewing. The speakers themselves are in acoustic enclosures mounted on either side, also helping to provide good stereo separation. A subwoofer is also built into the shelf to add some bass response, with an impressively-neat bass chamber design. Finished off with some LED lights and a USB hub, the design delivers great sound along with a lovely desk environment for getting work done.

[Matt] does love a nice DIY build; his water-cooled outdoor TV is a particular delight. Video after the break.

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Lego Fourteen-Segment Display Needs Plenty Of Motors

April 12, 2022 by 1 Comment

Hackers love 7-segment displays, and will gladly wax lyrical about the silly words you can almost spell on them and so on. Less appreciated are their bigger cousins, the fourteen and sixteen segment displays, which get all alphanumeric about things and are thus much easier for humans to read. You can even build the former out of Lego, as [ord] demonstrates.

A look at the mechanism driving the display.

The “segments” are made up of Lego shafts that are pushed up through a yellow matrix of holes when they are switched “on.” A full seven motors are used to make the single-character display work, each one driving two segments. Two Lego Powered Up controller bricks are required to drive everything going on here, making the final design not just mechanically complicated, but electronically complicated as well.

Amusingly, those don’t come cheap, either; the parts total cost of this build is likely somewhere between $50-100 US. You probably don’t want to build an entire scrolling message board using this design, even if it does look resplendent in black and taxi yellow.

We’ve seen [ord]’s work before, too, in the form of these mechanically magnificent 7-segment Lego displays. Video after the break.

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Hacking An Experimental ESA Satellite

April 12, 2022 by 5 Comments

Hacking these days means everything from someone guessing your password and spamming your contacts with toxic links, to wide-scale offensive cyberattacks against infrastructure by sophisticated operators backed by nation states. When it comes to hacking satellites, though, [Didelot Maurice-Michel] found himself tangling with some hardware belonging to the European Space Agency. 

As part of an event called HackCYSAT, hackers were invited to attack the ESA’s OPS-SAT, a CubeSat intended to demonstrate improved techniques for mission control and more advanced satellite hardware. The computer hardware on board is ten times more powerful than other existing ESA satellites, and aims to take satellite technology on a new leap forward.

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Bungee-Corded Bass Zither Really Slaps

April 12, 2022 by 13 Comments

Surely we’ve all played some bass riffs on a stretched-out rubber band before, right? [Nicolas Bras] found that the ultimate musical rubber bands are bungee cords, and used seven of them to build a double-bass zither that can be plucked or struck with drumsticks. Be sure to check it out in the build/demo video after the break.

[Nicolas] is what you might call a hardware store hacker. This is not his first instrumental rodeo by far; in fact, he has spent the last 15 years building instruments from stuff like PVC and other commonly-available items.

One thing in this build that’s not so commonly available is the large sound box [Nicolas] built to strap the bungee cords across. He also made custom bridges for the bungees that are topped with triangular wood, which makes them look like little row houses.

In order to actually play the thing, [Nicolas] arranged the row houses in a 2-point bridge system for dual-note strings, which sound good between the bridges and the bungee hooks, but not so much between the bridges themselves. Overall, the zither has a great, mellow sound no matter how he plays it, and we just might have to string one of these up ourselves.

Not a strings person? Then you might be sated by [Nicolas]’ PVC pipes, which play “Popcorn” perfectly.

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Hall Effect Module Knows Where Your Motor Is

April 12, 2022 by 22 Comments

If you have a motor and you’d like to know where the shaft position is, you are likely to turn to an optical encoder scheme. However, as [lingib] points out, you can also use a magnet and a magnetometer. You can see how it works in the video below.

The MLX90393 is a 3-axis hall effect device and, with a magnet on the shaft, the X and Y outputs of the spinning magnet will form a quadrature output that you can easily read.

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Skip The Shipping, Print Your Own Cable Chains

April 12, 2022 by 11 Comments

CNC machines and 3D printers tend to have plenty of cabling which must be neatly managed while the machine moves. If not properly taken care of, wires can easily end up tangled in the moving bits leading to a dead machine at best, and some kind of raucous fire at worst. [Nikodem Bartnik] decided to create his own cable chains for his CNC build to keep everything in check.

The benefit of cable chains is that they stop cables splaying everywhere while still allowing them to move as needed with the axes of the machine. [Nikodem] created 20mm and 40mm chains for his build, affixed into the aluminium extrusion with bolts and T-nuts for easy assembly. The chains are assembled by hand, with 3D printed clips that hammer in place to hold the cables inside once inserted.

Of course, there’s nothing stopping you from buying cable chains off the shelf. But if you don’t want to wait for shipping in this era of cursed supply chains, or you want a cable chain you can customize to perfectly suit your machine, making your own could be the way to go. 

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Ask Hackaday: Is It Time For Waste Heat And Cold Area Heating To Shine?

April 12, 2022 by 82 Comments

It’s difficult to escape the topic of energy supply at the moment, with the geopolitical situation surrounding the invasion of Ukraine leaving the natural gas supply to an entire continent in jeopardy. Fortunately we’re watching the green shoots of an early spring here in the Northern hemisphere so the worst of the winter weather is behind us, but industrial customers can take no such solace from the season and will have to weather whatever price hikes are to come. Every alternative idea for energy supply is on the table, and with the parallel imperative of decarbonising the economy this goes beyond the short term into a future without so much need to rely on gas.

The Future is Cloudy

A district heating plant in Vienna, Austria.
A district heating plant in Vienna, Austria. Joadl, CC BY-SA 3.0 AT

A collaboration between a Finnish district heating network and Microsoft caught our eye because the location of a new data centre for the tech giant was chosen specifically to supply waste heat to the network, rather than releasing it to the environment. It’s not uncommon at all for European cities to use district heating networks but they are normally supplied by waste incinerators, boilers, or combined heat and power stations. The use of data centre waste heat is a novelty, as is in particular the siting of the data centre being dictated by the network.
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