Hackaday Links: February 2, 2020

February 2, 2020 by Dan Maloney 17 Comments

Is it just me or did January seem to last for about three months this year? A lot has happened since the turn of the decade 31 days ago, both in the normie world and in our space. But one of the biggest pieces of news in the hacker community is something that won’t even happen for four more months: Hackaday Belgrade. The annual conference in Hackaday’s home-away-from-home in Serbia was announced, and as usual, one had to be a very early bird to score discount tickets. Regular tickets are still on sale, but I suspect that won’t last long. The call for proposals for talks went out earlier in the month, and you should really consider standing up and telling the world what you know. Or tell them what you don’t know and want to find out – there’s no better way to make connections in this community, and no better place to do it.

Someone dropped a tip this week about the possible closing of Tanner Electronics, the venerable surplus dealer located in Carrollton, Texas, outside of Dallas and right around the corner from Dallas Makerspace. The report from someone visiting the store is that the owner has to either move the store or close it down. I spoke to someone at the store who didn’t identify herself, but she confirmed that they need to either downsize or close. She said they’re actively working with a realtor and are optimistic that they’ll find a space that fits their needs, but the clock is ticking – they only have until May to make the change. We covered Tanner’s in a 2015 article on “The Death of Surplus”. It would be sad to lose yet another surplus store; as much as we appreciate being able to buy anything and everything online, nothing beats the serendipity that can strike walking up and down aisles filled with old stuff. We wish them the best of luck.

Are you finding that the smartphone in your pocket is more soul-crushing than empowering? You’re not alone, and more and more people are trying a “digital detox” to free themselves from the constant stimulation. And there’s no better way to go about this than by turning your smartphone into a not-so-smart phone. Envelope, a paper cocoon for your phone, completely masks the screen, replacing it with a simple printed keypad. A companion app allows you to take and make phone calls or use the camera, plus provides a rudimentary clock, but that’s it. The app keeps track of how long you can go before unwrapping your phone and starting those sweet, sweet dopamine hits again. It reminds us a bit of the story we also saw this week about phone separation anxiety in school kids, and the steps schools are taking to mitigate that problem.

We saw a lot of articles this week on a LoRaWAN security vulnerability. The popular IoT network protocol has been billed as “secure by default”, but a white paper released by cybersecurity firm IOActive found a host of potential attack vectors. Their main beef seems to be that client devices which are physically accessible can be reverse engineered to reveal their encryption keys. They also point out the obvious step of taking the QR code off of client devices so an attacker can’t generate session keys for the device.

And finally, the mummy speaks! If you ever wondered what the voice of someone who lived 3,000 years ago sounded like, wonder no more. Using computed tomography (CT) data, scientists in the UK and Germany have recreated the vocal tract of Nesyamun, an Egyptian scribe and priest from the time of pharaoh Rameses XI. He died in his mid-50s, and his mummified remains have been studied since the 1800s. CT data was used to 3D-print Nesyamun’s larynx and nasopharynx, which was then placed atop a “Vocal Tract Organ”, possibly the strangest musical instrument in existence. The resulting vowel-like utterance is brief, to say the least, but it’s clear and strong, and it’s pretty impressive that we can recreate the voice of someone who lived and died three millennia ago.

A Tiny USB Hub For All Your Hardware Modding Needs

February 2, 2020 by Tom Nardi 28 Comments

Going all the way hack to the heady days of Eee PC modding, hardware hackers have been on the hunt for small USB hubs that can easily be liberated from their enclosures and integrated into whatever project they happen to be working on. From time to time you see recommendations out there for makes and models which lend themselves to this sort of repurposing, but it’s seemed more difficult than necessary to source such a basic component.

Which is why [RETROCUTION] has developed a USB hub that’s not only extremely small, but relatively easy to assemble with only six components. Plus best of all, they are dirt cheap.

When you add up the cost of getting the PCBs made and buying all the SMD components, the per-unit price of these hubs is only going to be a few dollars. If you’ve got what it takes to make the PCBs in-house, even better. Considering how much easier these things could make other projects, it seems more than worth the upfront cost.

The star of the show is the FE1.1s, a four port USB 2.0 controller in a SSOP-28 package. As of this writing, it goes for about 25 cents from the usual overseas sources (even less, for larger orders). Add to the mix a few 10 μF ceramic capacitors, a 2.7 kΩ resistor, and a 12 MHz crystal.

There’s no provision for actual USB ports in the design, but they would just take up space anyway; this hub is intended to be directly soldered to the other devices. Incidentally, to reduce the number of traces and pads on the PCB, there aren’t power lines for the downstream devices either. So you’ll need to power them separately.

The passives are 0603, but the crystal is a good old fashioned through-hole component. [RETROCUTION] assembles the boards with a solder paste stencil and a hot air station, but if you’ve got a little practice, it’s certainly something you could do with an iron. With such a straightforward design, you could build a lifetime supply of these itty-bitty hubs in an afternoon. That’s certainly our plan, anyway.

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Pavlok Gets A Literally Shocking Teardown

February 2, 2020 by Tom Nardi 36 Comments

Apparently, there is a wrist-mounted device that delivers electric shocks to the wearer when it receives the appropriate command over Bluetooth. No, it’s not part of some kind of house arrest program. If you can believe it, the gadget is actually intended to help break bad habits or wake up exceptionally deep sleepers. We don’t know which of those problems [Becky Stern] has, but we’re glad to see she decided to take hers apart before the 21st century self-flagellation started.

Called the Pavlok and available for $180 USD from various online retailers, the device looks like a chunky fitness tracker. But in place of the screen that would show you how many steps you’ve taken or your current heart rate, there’s a lighting bolt button that you can press when you want to shock yourself. With the smartphone application, you can control the device remotely with a handy desktop widget that allows you to select the intensity of the shock. No, we aren’t making any of this up. Check out the video after the break to see it in action.

When [Becky] tried to take the Pavlok apart, she found that it was nearly impossible to handle it without inadvertently triggering a shock. So until she could get the case open and physically disconnect the battery, all she could do was turn the intensity down in the application and work through the occasional jolts from the device. We can only hope that more devices don’t adopt a similar sense of self-preservation.

Once inside she found mainly the same kind of hardware you’d expect in a standard, non-masochistic, fitness wearable. There’s a nRF52832 Bluetooth SoC, a MMA8451Q accelerometer, a PCF85063A I2C RTC, and a FXAS21002C gyroscope. What you’re somewhat less likely to find inside your FitBit however is the LPR6235 coupled inductor and beefy capacitors which are used to build up a high-voltage charge from the standard 3.7 V LiPo battery.

We’ve been very interested in the recent projects which are creating custom firmwares for commercially available fitness wearables, as it could be an express route to a hacker-friendly smartwatch. While the Pavlok has some compelling hardware, and the programming header [Becky] identified looks interesting, we don’t like the idea of being one misplaced if statement away from riding the lightning.

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Microcontroller Studies The Blade

February 2, 2020 by Bryan Cockfield 8 Comments

Kendo, a Japanese martial art, is practiced with a special sword. It’s not a particularly sharp sword, though, since the “blade” is essentially a length of bamboo. For this reason, Kendo practitioners must rely on correct form and technique in order to make sure their practice is as effective as possible, and Cornell students [Iman] and [Weichen] have made a Kendo trainer that helps the swordsmen in their art.

The core of the project is a PIC32 microcontroller hooked up to a set of three piezoelectric sensors and a LSM9DS1 inertial module. The three piezoelectric sensors are attached to a helmet and the inertial module to the sword, and the sensors work together to determine both the location of the strike and whether or not it had enough strength to be considered a “good” strike (the rules of Kendo are beyond the scope of this article). The trainer can then calculate all of the information and provide feedback to the user on a small screen.

While martial-arts related builds seem to be relatively rare, we did find a similar project from back in 2011 called the Virtual Sensei which used a then-popular Kinect in order to track movements. This PIC32-based project, though, seems to be a little more thorough by including the strength of the strike in the information the computer uses, and is probably less expensive to boot!

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Synthfonio Makes Music Easy Like Sunday Morning

February 2, 2020 by Kristina Panos 2 Comments

This one goes out to anyone who loves music and feels it in their soul, but doesn’t necessarily understand it in their head. No instrument should stand in the way of expression, but it seems like they all do (except for maybe the kazoo).

[FrancoMolina]’s hybrid synth-MIDI controller is a shortcut between the desire to play music and actually doing it. Essentially, you press one of the buttons along Synthfonio’s neck to set the scale, and play the actual notes by pressing limit switches in the controller mounted on the body. If you’re feeling blue, you can shift to minor scales by pressing the relative minor note’s neck button at the same time as the root note, e.g. A+C=Am. Want to change octaves? Just slide the entire controller up or down for a total of three.

All of these switches are muxed to two Arduinos — an MKR1010 for USB MIDI control, and a bare ‘328 to provide the baked-in synth sounds. Power comes from a stepped-up 18650 that can be charged with an insanely cheap board from that one site. [Franco] has all the code and files available, so go have fun making music without being turned off by a bunch of theory. Push that button there to check out the demo.

If ‘portable’ means pocket-sized to you, then let this mini woodwind MIDI controller take your breath away.

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Growing Human Neurons Hooked Up To Electrodes

February 2, 2020 by Lewin Day 11 Comments

Philosophers have long mused about the concept of a “brain in a jar”, but thus far, it’s remained the preserve of science fiction rather than reality. However, after reading some scientific papers, [Justin] wanted to attempt the feat himself, so set out to grow some human neurons on an electrode array.

The project builds on [Justin]’s earlier work, using his DC sputtering rig to coat a glass microscope slide with electrodes. The first layer is silver for high conductivity, with an added gold layer for biocompatibility. The screw cap from a Falcon tube is then epoxied on to act as a reservoir for culture media for the neurons. Finally, an air filter is added to allow the biological mixture to breathe.

This was [Justin]’s first attempt at culturing neurons, and there were plenty of hurdles along the way. The custom culture assemblies had issues with the epoxy bonds leaking or failing entirely, leading to only one slide making it through the sterilization process. Additionally, the neurons were accidentally added in too high a quantity. While some growth was observed under the microscope, [Justin] was unable to detect any real signal from the system.

Despite a poor final result, plenty was learned along the way. [Justin] has already put plans into place to fix some of the pitfalls of the original experiment, and we look forward to seeing future updates from the project. Video after the break.

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A Mini SDR Receiver Using An Audio DSP

February 1, 2020 by Jenny List 18 Comments

Software defined radio or SDR is the most exciting frontier in the field of radio, transferring as it does all signal functions from the analogue to the digital domain. Radios using SDR techniques can be surprisingly straightforward and easy to understand, and [Ray Ring]’s little SDR receiver manages to combine this with the novel use of an audio DSP rather than a computer to perform its SDR functions.

The front end is a conventional enough direct conversion design with an Si5531 clock generator providing I and Q phase-shifted local oscillator signals to a TS3A5017 analogue switch used as a mixer. An unexpected presence is an LTC6252 op-amp as an RF amplifier, but the special part comes after the I and Q baseband signals have been filtered. The SDR part of this receiver is an audio DSP, but it’s one that might not be an immediate choice. The Spin Semiconductor FV-1 is a dedicated digital reverb chip for musical effects boxes, but it comes with the feature that its internal DSP core can access custom code from an external ROM. [Ray] has written his own code for demodulation of AM, USB, and LSB signals rather than musical effects, and used the device’s left and right audio channels to process I and Q quadrature signals. The use of a single purpose chip to do something its designers never intended gives it the essence of a good hack, and we’re mightily impressed at his spotting the potential for an SDR in a musical effect. Hear it in action in the video below the break.

Meanwhile if the operation of a receiver such as this one is a mystery to you, we published a handy primer back in 2017.

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