Hackaday Podcast 049: Tiny Machine Learning, Basement Battery Bonanza, And Does This Uranium Feel Hot?

January 10, 2020 by Mike Szczys 3 Comments

Hackaday editors Mike Szczys and Elliot Williams sort through all of the hacks to find the most interesting hardware projects you may have missed this week. Did you know you can use machine learning without a neural network? Here’s a project that does that on an ATtiny85. We also wrap our minds around a 3D-printed press brake, look at power-saving features of the ESP32 that make it better on a battery, and discuss the IoT coffee maker hack that’s so good it could be a stock feature. Plus we dive into naturally occurring nuclear reactors and admire the common, yet marvelous, bar code.

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!

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.)

Continue reading “Hackaday Podcast 049: Tiny Machine Learning, Basement Battery Bonanza, And Does This Uranium Feel Hot?” →

Living At The Close Of The Multiway Era

January 9, 2020 by Jenny List 97 Comments

After over a decade of laptop use, I made the move a couple of months ago back to a desktop computer. An ex-corporate compact PC and a large widescreen monitor on a stand, and alongside them a proper mouse and my trusty IBM Model M that has served me for decades. At a stroke, the ergonomics of my workspace changed for the better, as I no longer have to bend slightly to see the screen.

The previous desktop PC was from an earlier time. I think it had whatever the AMD competitor to a Pentium 4 was, and if I recall correctly, its 512 MB of memory was considered to be quite something. On the back it had an entirely different set of sockets to my new one, a brace of serial ports, a SCSI port, and a parallel printer port. Inside the case, its various drives were served by a set of ribbon cables. It even boasted a floppy drive. By contrast the cabling on its successor is a lot lighter, with much less bulky connectors. A few USB plugs and a network cable, and SATA for its disk drive. The days of bulky multiway interconnects are behind us, and probably most of us are heaving a sigh of relief. Continue reading “Living At The Close Of The Multiway Era” →

Fail Of The Week: Thermostat Almost Causes A House Fire

January 8, 2020 by Dan Maloney 63 Comments

Fair warning: any homeowners who have thermostats similar to the one that nearly burned down [Kerry Wong]’s house might be in store for a sleepless night or two, at least until they inspect and perhaps replace any units that are even remotely as sketchy as what he found when he did the postmortem analysis in the brief video below.

The story begins back in the 1980s, when the Southern New England area where [Kerry] lives enjoyed a housing boom. Contractors rushed to turn rural farmland into subdivisions, and new suburbs crawled across the landscape. Corners were inevitably cut during construction, and one common place to save money was the home’s heating system. Rather than engage an HVAC subcontractor to install a complicated heating system, many builders opted instead to have the electricians install electric baseboards. They were already on the job anyway, and at the time, both copper and electricity were cheap.

Fast forward 40 years or so, and [Kerry] finds himself living in one such house. The other night, upon catching the acrid scent of burning insulation, he followed his nose to the source: a wall-mounted thermostat for his electric baseboard. His teardown revealed burned insulation, bare conductors, and scorched plastic on the not-so-old unit; bearing a 2008 date code, the thermostat must have replaced one of the originals. [Kerry] poked at the nearly combusted unit and found the root cause: the spot welds holding the wires to the thermostat terminal had become loose, increasing the resistance of the connection. As [Kerry] points out, even a tenth of an ohm increase in resistance in a 15 amp circuit would dissipate 20 watts of heat, and from the toasty look of the thermostat it had been a lot more than that.

The corner-cutting of the 1980s was nothing new, of course – remember the aluminum wiring debacle? Electrical fires are no joke, and we’re glad [Kerry] was quick to locate the problem and prevent it from spreading.

Continue reading “Fail Of The Week: Thermostat Almost Causes A House Fire” →

Commercial Circuit Simulator Goes Free

January 8, 2020 by Al Williams 118 Comments

If you are looking for simulation software, you are probably thinking LTSpice or one of the open-source simulators like Ngspice (which drives Oregano and QUCs-S), or GNUCap. However, there is a new free option after the closing of Spectrum Software last year: Micro-Cap 12. You may be thinking: why use another closed-source simulator? Well, all the simulators have particular strengths, but Micro-Cap does have very nice features and used to retail for about $4,500.

The simulator boasts a multipage schematic editor, native robust digital simulation, Monte Carlo analysis, 33,000 parts in its library, worst-case and smoke analysis, Smith charts, and it can even incorporate spreadsheets. There’s a built-in designer for active and passive filters. Have a look at the brochure and you will see this is a pretty serious piece of software. And now it’s at least free as in beer.

Continue reading “Commercial Circuit Simulator Goes Free” →

Choosing The Right Battery For Your Electric Vehicle Build

January 7, 2020 by Lewin Day 43 Comments

Many a hacker has looked at their scooter, bike, or skateboard, and decided that it would be even better if only it had a motor on it. Setting out to electrify one’s personal transport can be an exciting and productive journey, and one that promises to teach many lessons about mechanical and electronic engineering. Fundamentally, the key to any build is the battery, which has the utmost say in terms of your vehicle’s performance and range. To help out, we’ve prepared a useful guide on selecting the right battery for your needs.

One Chemistry To Rule Them All

Batteries come in all shapes and sizes, and a variety of different chemistries that all have their own unique properties and applications. When it comes to small electric vehicles, it’s desirable to have a battery with a low weight, compact size, plenty of current delivery for quick acceleration, and high capacity for long range.

30 years ago, options were limited to lead acid, nickel cadmium, and nickel metal hydride batteries. These were heavy, with low current output, poor capacity, and incredibly slow charge times. Thankfully, lithium polymer batteries have come along in the meantime and are more capable across the board. Offering huge discharge rates, fast charging, light weight and high capacity, they’re undeniably the ultimate choice for a high performance electric vehicle. They’re also wildly popular, and thus cheap, too!

There are some hangups, however. It’s important to keep all the cells in a pack at the same voltage in order to avoid cells back-charging each other. This can cause damage to the pack, or even explosions or fire. Maintaining the battery voltages to avoid this is called “balancing”. It can be handled in various ways, depending on the exact style of battery you’re using, as we’ll cover later.

Additionally, lithium batteries do not like being over-discharged. As a rule of thumb, it’s a good idea not to let your batteries drop below 3.0 V per cell. Failure to keep this in check can lead to ruining a pack, hurting its maximum capacity and ability to deliver current.

There are thankfully ways around these issues, and which ones you use depends on the battery you choose for your application. Continue reading “Choosing The Right Battery For Your Electric Vehicle Build” →

Organic Audio: Putting Carrots As Audio Couplers To The Test

January 6, 2020 by Jenny List 34 Comments

[Boltz999]'s carrot interconnect. — [Boltz999]’s carrot interconnect.

If there’s one thing that gives us joy here at Hackaday it’s a story of audio silliness. There is a rich vein of dubious products aimed at audiophiles which just beg to be made fun of, and once in a while we oblige. But sometimes an odd piece of audio equipment emerges with another purpose. Take [Boltz999]’s interconnects for example, which were born of necessity when there were no female-to-female phono adapters to connect a set of cables. Taking a baby carrot and simply plugging the phonos into its flesh delivered an audio connectivity solution that worked.

Does this mean that our gold-nanoparticle-plated oxygen-free directional audio cables are junk, and we should be heading for the supermarket to pick up a bag of root vegetables instead? I set out to test this new material in the secret Hackaday audio lab, located on an anonymous 1970s industrial estate in Milton Keynes, UK.

Continue reading “Organic Audio: Putting Carrots As Audio Couplers To The Test” →

Hackaday Links: January 5, 2020

January 5, 2020 by Dan Maloney 30 Comments

It looks like the third decade of the 21st century is off to a bit of a weird start, at least in the middle of the United States. There, for the past several weeks, mysterious squads of multicopters have taken to the night sky for reasons unknown. Witnesses on the ground report seeing both solo aircraft and packs of them, mostly just hovering in the night sky. In mid-December when the nightly airshow started, the drones seemed to be moving in a grid-search pattern, but that seems to have changed since then. These are not racing drones, nor are they DJI Mavics; witnesses report them to be 6′ (2 meters) in diameter and capable of staying aloft for 90 minutes. These are serious professional machines, not kiddies on a lark. So far, none of the usual government entities have taken responsibility for the flights, so speculation is all anyone has as to their nature. We’d like to imagine someone from our community will get out there with radio direction finding gear to locate the operators and get some answers.

We all know that water and electricity don’t mix terribly well, but thanks to the seminal work of White, Pinkman et al (2009), we also know that magnets and hard drives are a bad combination. But that didn’t stop Luigo Rizzo from using a magnet to recover data from a hard drive. He reports that the SATA drive had been in continuous use for more than 11 years when it failed to recover after a power outage. The spindle would turn but the heads wouldn’t move, despite several rounds of percussive maintenance. Reasoning that the moving coil head mechanism might need a magnetic jump-start, he probed the hard drive case with a magnetic parts holder until the head started moving again. He was then able to recover the data and retire the drive. Seems like a great tip to file away for a bad day.

It seems like we’re getting closer to a Star Trek future every day. No, we probably won’t get warp drives or transporters anytime soon, and if we’re lucky velour tunics and Spandex unitards won’t be making a fashion statement either. But we may get something like Dr. McCoy’s medical scanner thanks to work out of MIT using lasers to conduct a non-contact medical ultrasound study. Ultrasound exams usually require a transducer to send sound waves into the body and pick up the echoes from different structures, with the sound coupled to the body through an impedance-matching gel. The non-contact method uses pulsed IR lasers to penetrate the skin and interact with blood vessels. The pulses rapidly heat and expand the blood vessels, effectively turning them into ultrasonic transducers. The sound waves bounce off of other structures and head back to the surface, where they cause vibrations that can be detected by a second laser that’s essentially a sophisticated motion sensor. There’s still plenty of work to do to refine the technique, but it’s an exciting development in medical imaging.

And finally, it may actually be that the future is less Star Trek more WALL-E in the unlikely event that Segway’s new S-Pod personal vehicle becomes popular. The two-wheel self-balancing personal mobility device is somewhat like a sitting Segway, except that instead of leaning to steer it, the operator uses a joystick. Said to be inspired by the decidedly not Tyrannosaurus rex-proof “Gyrosphere” from Jurassic World, the vehicle tops out at 24 miles per hour (39 km/h). We’re not sure what potential market for these things would need performance like that – it seems a bit fast for the getting around the supermarket and a bit slow for keeping up with city traffic. So it’s a little puzzling, although it’s clearly easier to fully automate than a stand-up Segway.