Know Audio: A Loudspeaker Primer

June 25, 2021 by 27 Comments

As we’ve started out on our journey through the world of Hi-Fi audio from a strictly practical and engineering viewpoint without being misled by any audiophile woo, we’ve already taken a look at the most important component in any audio system: the listener’s ear. It’s time to move down the chain to the next link; the loudspeaker.

Sound is pressure waves in the air, and the purpose of a loudspeaker is to move the air to create those waves. There are a variety of “exotic” loudspeaker technologies including piezoelectric and electrostatic designs, here we’ll be considering the garden variety moving-coil speaker. It’s most usually used for the large bass or smaller mid-range drivers in a typical speaker system. Continue reading “Know Audio: A Loudspeaker Primer” →

Hackaday Podcast 124: Hard Drivin’ With Graphene, Fooled By Lasers, Etching With Poison Acid, And All The Linux Commands

June 25, 2021 by 4 Comments

Hackaday editors Elliot Williams and Mike Szczys marvel at the dangerous projects on display this week, including glass etching with hydrofluoric acid and pumping 200,000 A into a 5,000 A fuse. A new board that turns the Raspberry Pi into an SDR shows off the power of the secondary memory interface (SMI) present in those Broadcom chips. We also discuss the potential for graphene in hard drives, and finish up with a teardown of a very early electronic metronome.

You know you want to read the show notes!

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (55 MB or so.)

Places to follow Hackaday podcasts:

Continue reading “Hackaday Podcast 124: Hard Drivin’ With Graphene, Fooled By Lasers, Etching With Poison Acid, And All The Linux Commands” →

Game Boy Color Gets A Rechargeable Battery

June 25, 2021 by 21 Comments

Nintendo’s classic Game Boy has long been the darling queen of the handheld scene. However, with many fans modifying their handhelds with power-sucking features like modern backlit LCDs, running on AA batteries can become a frustrating exercise as they rapidly run out. [esotericsean] gets around that by modifying his Game Boys with a USB rechargeable battery setup. (Video, embedded below.)

The hack is a simple one, but the execution is quite tidy. [esotericsean] starts by removing the original DC jack from the Game Boy motherboard, and hogs out the hole in the case to fit a micro USB port. The original battery housing is similarly carved out to suit a 2000 mAh lithium-polymer pouch cell. A single-cell charging board is used to manage the battery, with its original connector removed and replaced with a neater-looking panel mount micro USB port instead. The electronics is then wrapped up in Kapton tape and stuffed inside the shell as everything is put back together.

The result is a USB rechargeable Game Boy that lasts for ages. [esotericsean] reports playing the console for hours each day for a full week without running out of power. The hack could become popular with chiptuners who often knock AA cells out of their handhelds during the more enthusiastic parts of their sets. We’ve seen similar hacks for other Game Boy models, too. Continue reading “Game Boy Color Gets A Rechargeable Battery” →

This Week In Security: Schemeflood, Modern Wardialing, And More!

June 25, 2021 by 17 Comments

There’s been yet another technique discovered to fingerprint users, and this one can even work in the Tor browser. Scheme flooding works by making calls to application URLs, something like steam://browsemedia. If your machine supports the requested custom URL, a pop-up is displayed, asking permission to launch the external application. That pop-up can be detected by JavaScript in the browser. Detect enough apps, and you can build a reasonable fingerprint of the system the test is run on. Unlike some previous fingerprinting techniques, this one isn’t browser dependent — it will theoretically give the same results for any browser. This means even the Tor browser, or any browser being used over the Tor network, can give your potentially unique set of installed programs away.

Now for the good news. The Chrome devs are already working on this issue, and in fact, Chrome on my Linux desktop didn’t respond to the probes in a useful way. Feel free to check out the demo, and see if the results are accurate. And as for Tor, you really should be running that on a dedicated system or in a VM if you really need to stay anonymous. And disable JavaScript if you don’t want the Internet to run code on your computer.
Continue reading “This Week In Security: Schemeflood, Modern Wardialing, And More!” →

3D Printed Mecanum Wheels For Hoverboard Motors

June 25, 2021 by 9 Comments

At this point, somebody taking the motors out of a cheap “hoverboard” and using them to power a scooter or remote controlled vehicle isn’t exactly a new idea. But in the case of the FPV rover [Proto G] has been working on, his choice of motors is only part of the story. The real interesting bit is the 3D printed omnidirectional Mecanum wheels he’s designed to fit the motors, which he thinks could have far reaching applications beyond his own project.

Now, that isn’t to say that the rover itself isn’t impressive. All of the laser cutting and sheet metal bending was done personally by [Proto G], and we love the elevated GoPro “turret” in the front that lets him look around while remotely driving the vehicle. Powered by a pair of Makita cordless tool batteries and utilizing hobby-grade RC parts, the rover looks like it would be a fantastic robotic platform to base further development on.

The Mecanum wheels themselves are two pieces, and make use of rollers pulled from far smaller commercially available wheels. This is perhaps not the most cost effective approach, but compared to the alternative of trying to print all the rollers, we see the advantage of using something off-the-shelf. If you’re not sure how to make these weird wheels work for you, [Proto G] has also released a video explaining how he mixes the RC channels to get the desired omnidirectional movement from the vehicle.

If you’re content with more traditional wheeled locomotion, we’ve previously seen how quickly a couple of second-hand hoverboards can be turned into a impressively powerful mobile platform for whatever diabolical plans you may have.

Continue reading “3D Printed Mecanum Wheels For Hoverboard Motors” →

Simulating The Game Boy Printer’s Actual Paper Output

June 25, 2021 by 7 Comments

Sometimes, we appreciate electronic devices not for their outright performance and crystal clear output, but precisely because they kind of suck in a unique and charming way. The Game Boy Camera, and its companion the Game Boy Printer, are much loved for precisely this reason. [Raphael BOICHOT] decided that he wanted to simulate the analog reality of the latter printer’s output in code, and set about the hefty coding task.

The result is the Game Boy Printer Paper Simulation, and it does a great job of reproducing the grainy, somewhat noisy output of the original thermal printer. The simulation was coded with the assistance of multiple high-resolution scans of the original printer’s output, which allowed [Raphael] to create a mathematical model of how the original digital pixelized image came out when hot thermal print head was put to paper.

What started with a single dot became a fully-fledged simulation package that can be run in MATLAB and Octave. It allows the end user to generate legitimate-looking images of Game Boy Printer output without actually having to own the printer and a roll of thermal paper.

We’ve seen Nintendo’s much-beloved printer before, such as this hack that turns it into an 8-bit photo gun. If you’re meddling with thermal printers yourself, be sure to let us know!

 

Review And Teardown Of Economical Programmable DC Power Supply

June 24, 2021 by 14 Comments

[Kerry Wong] isn’t afraid to get his hands dirty, and is always more than willing to open things up and see what makes them tick. This time, he reviews and tears down the Topshak LW-3010EC programmable DC power supply, first putting the unit through its paces, then opens it up to see how it looks on the inside.

The Topshak LW-3010EC is in a family of reasonably economical power supplies made by a wide variety of manufacturers, which all share many of the same internals and basic construction. This one is both programmable as well as nice and compact, and [Kerry] compares and contrasts it with other power supplies in the same range as he tests the functions and  checks over the internals.

Overall, [Kerry] seems pleased with the unit. You can watch him put the device through its paces in the video embedded below, which ends with him opening it up and explaining what’s inside. If you’ve ever been curious about what’s inside one of these power supplies and how they can be expected to perform, be sure to fire up the video below the page break.

Speaking of power supplies, most of us have ready access to ATX power supplies. They are awfully capable pieces of hardware, and hackable in their own way. Our own Jenny List will tell you everything you need to know about the ATX power supply, and how to put it to new uses.

Continue reading “Review And Teardown Of Economical Programmable DC Power Supply” →