Button, Button, Who’s Got The (One) Button?

December 17, 2018 by 17 Comments

We often think that less is more, but what can you do with a device that has only a single button? [Danko Bertović] wondered the same thing and he built an Arduino with a single button and a display. After doing some obvious things  (like a counter or stopwatch) he decided to make a calculator for his latest Volos Projects video.

You can find the source code online and he used a library from GitHub to handle the reaction to single presses, double presses, and long presses. Is it ideal? Probably not. But if you only have a limited amount of space or pins, it can make the difference between a feasible project and one you can’t finish.

His original projects also included a Flappy Bird clone. The OLED display is only 64×48 so that’s not a lot of room. The packaging of the tiny Arduino, the battery, and the display in a good looking case, was pretty impressive. So the device might be usable for something.

Of course, the library will work with any program and there’s no reason you can’t have more than one button and simply multiply their functions with the same strategy. There’s a sample on GitHub that shows how you can create two OneButton objects connected to different hardware devices.

By the way, the little box may have only one button, but it also has a power switch. Turns out, you can use it as an input in certain circumstances. If the OLED display strikes you as too luxurious, try the DUO BINARY.

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Welcome To The Slow Death Of Satellite TV In America

December 17, 2018 by 131 Comments

During an earnings call on November 29th, CEO of AT&T Communications John Donovan effectively signed the death warrant for satellite television in the United States. Just three years after spending $67 billion purchasing the nations’s largest satellite TV provider, DirecTV, he made a comment which left little doubt about the telecom giant’s plan for the service’s roughly 20 million subscribers: “We’ve launched our last satellite.”

The news might come as a surprise if you’re a DirecTV customer, but the writing has been on the wall for years. When the deal that brought DirectTV into the AT&T family was inked, they didn’t hide the fact that the actual satellite content delivery infrastructure was the least of their concerns. What they really wanted was the installed userbase of millions of subscribers, as well as the lucrative content deals that DirecTV had already made. The plan was always to ween DirecTV customers off of their satellite dishes, the only question was how long it would take and ultimately what technology they would end up using.

Now that John Donovan has made it clear their fleet of satellites won’t be getting refreshed going forward, the clock has officially started ticking. It won’t happen this year, or even the year after that. But eventually each one of the satellites currently beaming DirecTV’s content down to Earth will cease to function, and with each silent bird, satellite television (at least in the United States) will inch closer to becoming history.

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A Deep Dive Into Low Power WiFi Microcontrollers

December 17, 2018 by 39 Comments

The Internet of Things is eating everything alive, and the world wants to know: how do you make a small, battery-powered, WiFi-enabled microcontroller device? This is a surprisingly difficult problem. WiFi is not optimized for low-power operations. It’s power-hungry, and there’s a lot of overhead. That said, there are microcontrollers out there with WiFi capability, but how do they hold up to running off of a battery for days, or weeks? That’s what [TvE] is exploring in a fantastic multi-part series of posts delving into low-power WiFi microcontrollers.

The idea for these experiments is set up in the first post in the series. Basically, the goal is to measure how long the ESP8266 and ESP32 will run on a battery, using various sleep modes. Both the ESP8266 and ESP32 have deep-sleep modes, a ‘sleep’ mode where the state is preserved, a ‘CPU only’ mode that turns the RF off, and various measures for sending and receiving a packet.

The takeaway from these experiments is that a battery-powered ESP8266 can’t be used for more than a week without a seriously beefy battery or a solar panel. Run times are much longer with an open network as compared to a secured network, and that security eats up a ton of power: connecting to a secure network every now and again means your ESP might only run for a day, instead of a week.

There is another option, though: the ESP32. While the ’32 is vastly more powerful and more capable than the ESP8266, it also has a few improved features that help with power consumption. Importantly, there’s a bug in the ESP8266 where it drops into modem sleep instead of light sleep about half the time. This error was fixed in the ESP32, but all that power does come at a cost. On the whole, if you’re concerned about security, the ESP32 is slightly better, simply because it does the ‘security’ part of connecting to a WiFi network faster. This is really a remarkable amount of testing that’s gone into this write-up, so if you’re developing something battery-powered with any ESP, it’s well worth the read.

‘Bit’ Installation Combines Art, Markov Chains

December 17, 2018 by 7 Comments

A Markov chain is a mathematical concept of a sequence of events, in which each future event depends only on the state of the previous events. Like most mathematical concepts, it has wide-ranging applications from gambling to the stock market, but in this case, [Jonghong Park] has applied it to art.

The installation, known simply as ‘bit’, consists of four machines. Each machine has two microswitches, which are moved around two wooden discs by a stepper motor. The microswitches read bumps on the surface of the disc as either a 0 or 1, and the two bits from the microswitches represent the machine’s “state”.

When a machine is called, the stepper motor rotates 1/240th of a revolution, and then the microswitches read the machine’s current state. Based on this state and the Markov Chain algorithm coded into the machines, a machine with the corresponding state is then called, which in turn moves, continuing the chain.

The piece is intended to reflect the idea of a deterministic universe, one in which the current state can be used to predict all future states. As an art piece, it combines its message with a visually attractive presentation of understated black metal and neatly finished wood.

We love a good art installation here at Hackaday – like this amazing snowflake install from a couple years back. Video after the break.

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Musical Mod Lets MRI Scanner Soothe The Frazzled Patient

December 16, 2018 by 27 Comments

Hackers love to make music with things that aren’t normally considered musical instruments. We’ve all seen floppy drive orchestras, and the musical abilities of a Tesla coil can be ear-shatteringly impressive. Those are all just for fun, though. It would be nice if there were practical applications for making music from normally non-musical devices.

Thanks to a group of engineers at Case Western Reserve University in Cleveland, there is now: a magnetic resonance imaging machine that plays soothing music. And we don’t mean music piped into the MRI suite to distract patients from the notoriously noisy exam. The music is actually being played through the gradient coils of the MRI scanner. We covered the inner working of MRI scanners before and discussed why they’re so darn noisy. The noise basically amounts to Lorenz forces mechanically vibrating the gradient coils in the audio frequency range as the machine shapes the powerful magnetic field around the patient’s body. To turn these ear-hammering noises into music, the researchers converted an MP3 of [Yo Yo Ma] playing [Bach]’s “Cello Suite No. 1” into encoding data for the gradient coils. A low-pass filter keeps anything past 4 kHz from getting to the gradient coils, but that works fine for the cello. The video below shows the remarkable fidelity that the coils are capable of reproducing, but the most amazing fact is that the musical modification actually produces diagnostically useful scans.

Our tastes don’t generally run to classical music, but having suffered through more than one head-banging scan, a half-hour of cello music would be a more than welcome change. Here’s hoping the technique gets further refined.

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Cheap Multimeter Leads Come With Extra Ohms, Free!

December 16, 2018 by 23 Comments

[Nop head] discovered that cheap multimeter leads costing only a few bucks can come with more than one may have bargained for. The first set had a large amount of useful-looking attachments, but the wires used for the leads were steel with a resistance of about one ohm each. With two leads in use, that means any resistance measurement gets two ohms added for free. More seriously, when measuring current, the wires can heat up rapidly. Voltage measurements would be affected the least, but the attachments and lead design expose a large amount of bare metal, which invites accidental shorts and can be a safety hazard with higher voltages.

Are all cheap multimeter leads similarly useless? Not necessarily. [nop head] also purchased the set pictured here. It has no attachments, but was a much better design and had a resistance of only 64 milliohms. Not great, but certainly serviceable and clearly a much better value than the other set.

It’s usually not possible to identify garbage before it’s purchased, but [nop head] reminds us that if you do end up with trash in hand, poor quality counterfeits can be good for a refund. That goes for electronic components, too.

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Hackaday Links: December 16, 2018

December 16, 2018 by 12 Comments

Microsoft is really leaning into vaporwave these days. Microsoft is giving away knit Windows sweaters to social media influencers. Is it for an ugly sweater contest? Maybe, or maybe Microsoft is capitalizing on the mid-90s ＡＥＳＴＨＥＴＩＣ. Recently, Apple got back in their 90s logo game with the release of a few ‘rainbow Apple’ t-shirts. The spirit of the 90s lives on in tech culture.

Have a Hackerspace? Frack is organizing the great Inter-hackerspaces Xmas goodies swap! Since your hackerspace is filled with weird ephemera and random crap, why not box it up and send it out to another hackerspace? You’ll probably get another random box of crap in return!

Just an observation looking for commentary, but is Thingiverse slow these days? It seems really, really, really slow these days.

The Blockchain makes it to the Apple II! By far, the most interesting thing in tech right now is the blockchain, with AI, at the edge. This will get your Merkle trees tinglin’ with some AI, and 5G is where it’s at. We’re back with cylinder computing this time, and this is the greatest achievement that will synthesize brand new paradigms. Of course, if it weren’t for millennials, we’d have it already.

There’s a new portable console out there, and it’s at the top of everyone’s Christmas lists. The SouljaGame Handheld is a rebrand of what’s available on AliExpress. What makes this one different? It has Soulja Boy’s name on it. If you couldn’t get your hands on the SouljaGame Handheld, don’t worry: Post Malone Crocs are available on eBay for about $300.