Ask Hackaday: What Can Be Done With Your Bootlooping Blu-Ray?

June 26, 2020 by Lewin Day 159 Comments

Last Friday, thousands of owners of Samsung Blu Ray players found that their home entertainment devices would no longer boot up. While devices getting stuck in a power-cycling loop is not uncommon, this case stands out as it affected a huge range of devices all at the same time. Samsung’s support forum paints a bleak picture, with one thread on the issue stretching to 177 pages in just a week.

So what is going on, and what can be done to fix the problem? There’s a lot of conflicting information on that. Some people’s gear has started working again, others have not and there are reports of customers being told to seek in-person repair service. Let’s dive in with some wild speculation on the problem and circle back by commiserating about the woes of web-connected appliances.

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Hackaday Podcast 073: Betrayal By Clipboard, Scratching 4K, Flaming Solder Joints, And Electric Paper

June 26, 2020 by Mike Szczys No comments

Hackaday editors Mike Szczys and Elliot Williams review a great week in the hacking world. There’s an incredible 4k projector build that started from a broken cellphone, a hand-cranked player (MIDI) piano, and a woeful story of clipboard vulnerabilities found in numerous browsers and browser-based apps. Plus you’ll love the field-ready solder splice that works like a strike-on box match (reminiscent of using thermite to weld railroad rail) and we spend some time marveling at the problem of finding power cuts on massive grid systems.

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 (60 MB or so.)

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Get The Party Started With A Mesh WiFi Light Show

June 26, 2020 by Sven Gregori 1 Comment

Wildly blinking LEDs may not be the ideal lighting for the average office environment, but they’ll surely spice up any party. And since a party without music is just a meeting, having both synced up is a great way to set the mood. Sure, you could simply roll out your standard LED strip instead, but that gets a bit boring, and also a bit tricky if you want to light up several places the same way. [Gerrit] might have built the perfect solution though, with his (mu)sic (R)eactive (Li)ghts, or muRLi, which are a set of individual lights that synchronize a programmable pattern over WiFi.

The system consists of muRLi itself as the base station that defines and sends the light pattern through WebSockets, and several muRLi Nodes that house a set of WS2812B LEDs to receive and display it. Both are built around a Wemos D1 Mini configured to set up a WiFi mesh network, and depending what’s in reach, the nodes connect either to the base station or other nodes, giving the system definitely enough reach for any location size. The music is picked up by a MAX4466-amplified microphone inside the base station — adding some more flexibility to positioning the system — and analyzed for volume and audio spectrum, which is also shown on an OLED.

The best part however is how the light patterns are programmed. Instead of hard-coding it into the firmware, [Gerrit] went for a modular approach with little ROM cartridges to plug into the muRLi base station. The cartridge itself contains just an I2C EEPROM, storing JavaScript code that is interpreted by the firmware using mJS. The scripts have access to the analyzed audio data and amount of LEDs within the network, and can dynamically generate the patterns as needed that way. Everything is neatly housed in 3D-printed enclosures, with all the design and source files available on the project’s GitHub page — but see for yourself in the video after the break.

If you don’t care about the wireless part but enjoy light synced up with music, have a look at a plain MIDI solution for that. As for [Gerrit], we’re definitely looking forward to seeing his next endeavor one day, since we also enjoyed his last one.

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Teardown Of The Singaporean COVID-19 TraceTogether Token

June 25, 2020 by Maya Posch 63 Comments

A large part of fighting against the SARS-CoV-2 pandemic is the practice of contact tracing, where the whereabouts of an infected person can be traced and anyone who has been in contact with that person over the past days tested for COVID-19. While smartphone apps have been a popular choice for this kind of tracing, they come with a range of limitations, which is what the TraceTogether hardware token seeks to circumvent. Now [Sean “Xobs” Cross] has taken a look at the hardware that will be inside the token once it launches.

Recently, [Sean] along with [Andrew “bunnie” Huang] and a few others were asked by GovTech Singapore to review their TraceTogether hardware token proposal. At its core it’s similar to the Simmel contact tracing solution – on which both are also working – with contacts stored locally in the device, Bluetooth communication, and a runtime of a few months or longer on the non-rechargeable batteries.

The tracing protocol used is BlueTrace, which is an open application protocol aimed at digital contact tracing. It was developed by the Singaporean government, initially for use with their TraceTogether mobile app.

This smartphone app showed a number of issues. First is that Apple does not allow for iOS apps to use Bluetooth in the background, requiring the app to be active in the foreground to be useful. Apple has its own tracing protocol, but it does not cover the requirements for building a full contact graph, as [Andrew] covers in more detail. Finally, the app in general is not useful to those who do not have a recent (compatible) smartphone, or who do not have a smartphone at all.

A lot of the challenges in developing these devices lie in making them low-power, while still having the Bluetooth transceiver active often enough to be useful, as well as having enough space to store interactions and the temporary tokens that are used in the tracing protocol. As Simmel and the TraceTogether tokens become available over the coming months, it will be interesting to see how well these predictions worked out.

A Baby Grand Gets MIDI

June 25, 2020 by Al Williams 10 Comments

Like a lot of people, [Jacques] doesn’t think a big hunk of plastic light enough to carry under your arm is a piano, even if it does have 88 keys. A piano is supposed to be a hefty piece of furniture that you have to buy people pizza to help you move. So he bought a used baby grand piano. It wasn’t in very good shape, though, so while restoring it, he also added MIDI to it. You can see the finished result in the video below.

At $100, the price was right, although it cost more to move it. Between water damage, moth attacks, and storage in a garage, the piano — an old Zimmerman — needed a lot of tender loving care. When it came to MIDI, [Jacques] found a used Disklavier — a very expensive piece of kit — but it didn’t fit the Zimmerman or another piano at hand. The solenoids and optical sensors are set up for a particular piano, so what can you do? Easy! Rebuild the bar that holds the solenoids and sensors.

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Excercise Ball Makes A Passable Landing Gear

June 25, 2020 by Lewin Day 17 Comments

Exercise balls are great for many things, from amusing children to breaking everything in your living room, often in quick succession. After seeing some German WWII prototype aircraft with wild landing gear designs, the [FliteTest] crew decided to see whether they could use an exercise ball to build a plane ready for even the bumpiest of runways.

Comparisons to the Gee Bee R-1 abound in the video.

The exercise ball created some constraints on the design, due to its weight and the large amount of drag it creates. To work around this, the design features a foamcore and carbon fibre construction to save weight. The exercise ball is placed front and center, serving as both the nose and landing gear of the aircraft. V-tails are used to place the rear control surfaces outside of the shadow of the ball, to help maintain control authority. Initial tests of the airframe showed handling problems. The team solved this by using a pair of gyro stabiliser boards of their own design, named Aura.

With the issues solved, the final aircraft is hilarious to behold. The huge, bouncing ball makes an excellent landing gear, able to launch off lumps and bumps and even skim over water. We’ve seen [FliteTest] get up to other escapades in the past, too. Video after the break.

[Thanks to Baldpower for the tip!]

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Measuring The Time Is A Breeze With This Air Flow Clock

June 25, 2020 by Dan Maloney 15 Comments

If you’ve ever had surgery, and you’re over a certain age, chances are good you’re familiar with the dreaded incentive spirometer. It’s a little plastic device with one or more columns, each of which has a plastic ball in it. The idea is to blow into the thing to float the balls, to ensure that your lungs stay in good shape and reduce the chance of pneumonia. This unique air-powered clock reminds us a little of that device, without all the pain.

Like a spirometer, [Nir Tasher]’s clock has three calibrated tubes, each big enough to hold a foam ball loosely. At the bottom of each tube is a blower whose motor is under PWM control. A laser rangefinder sits below each ball and measures its height; the measurement is used by a PID loop to control the speed of each fan and thus the height of each ball. The video below shows that the balls are actually pretty steady, making the clock easy to read. It doesn’t, however, reveal what the clock sounds like; we’re going to go out on a limb here and guess that it’s pretty noisy. Still, we think it’s a fantastic way to keep time, and unique in the extreme.

[Nir]’s Air Flow clock is an early entry in the 2020 Hackaday Prize, the greatest hardware design contest on Earth. Everyone should enter something, or at least check out the cool things people are coming up with. It’s still early in the process, but there are so many neat projects already. What are you waiting for?

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