Giant Clock Made In The Nick Of Time

When [tnjyoung] was asked to build a huge lighted clock for a high school theater’s production of Cinderella with only two weeks before opening night, he probably wished for a fairy godmother of his own to show up and do it for him. But he and his team pulled it off, and it looks amazing. That medallion in the middle? It was laid out painstakingly by hand, using electrical tape.

This thing is 12 feet wide and weighs more than 500 pounds. Even so, it isn’t a permanent set piece, so it has to move up and down throughout the show on airplane cables. Now for the minutiae: there’s an Arduino Uno with built-in Wi-Fi that receives UDP commands from a phone to raise and lower the clock at the appropriate times. The ‘duino is also controlling two stepper motors, one for the hour hand and one for the minute hand.

Time is almost a minor character in the story of Cinderella, since she has to get back by midnight. Because of this, [tnjyoung] programmed a dozen or so time cues that move the steppers at various speeds to achieve different effects, like time flying by as she dances the night away with the Prince. Hour you still just sitting there? Sweep past the break to watch the build process fly by in a matter of minutes.

Got all the time in the world? Make a clock out of clocks. Clocks all the way down.

Continue reading “Giant Clock Made In The Nick Of Time”

Project Rubicon: The NSA Secretly Sold Flawed Encryption For Decades

There have been a few moments in the past few years, when a conspiracy theory is suddenly demonstrated to be based in fact. Once upon a time, it was an absurd suggestion that the NSA had data taps in AT&T buildings across the country. Just like Snowden’s revelations confirmed those conspiracy theories, a news in February confirmed some theories about Crypto AG, a Swiss cryptography vendor.

The whole story reads like a cold-war era spy thriller, and like many of those novels, it all starts with World War II. As a result of a family investment, Boris Hagelin found himself at the helm of Aktiebolaget Cryptograph, later renamed to Crypto AG (1952), a Swedish company that built and sold cipher machines that competed with the famous Enigma machine. At the start of the war, Hagelin decided that Sweden was not the place to be, and moved to the United States. This was a fortuitous move, as it allowed Hagelin to market his company’s C-38 cipher machine to the US military. That device was designated the M-209 by the army, and became the standard in-the-field encryption machine.

Continue reading “Project Rubicon: The NSA Secretly Sold Flawed Encryption For Decades”

ESP32 Rover With PCB Chassis Is Ready To Roll

The microcontrollers are cheap, the sensors are cheap, even the motors are cheap. So why are all the good wheeled robotics platforms so expensive? [Dimitris Platis] wanted to develop an affordable platform for experimenting with rovers, but the cheap plastic chassis he was using gave him all sorts of problems. So he did what any good hacker would do, and built a better version himself.

Interestingly, [Dimitris] decided to go with a chassis made from two PCB panels. The motors, mounted to small angled brackets, bolt directly to the lower PCB. These aren’t your standard $2 DC cans either. Each JGB37-520 gearhead motor comes complete with an encoder that allows your software to determine speed, distance, and direction. The upper PCB connects to the lower with several rows of pin headers, and plays host to whatever electronics payload you might be experimenting with at the time.

For the controller, [Dimitris] says the ESP32 is hard to beat by pretty much any metric you want to use. With integrated wireless and considerable computational power, there’s plenty of options for controlling your little rover either remotely or autonomously. But he also says that every effort has been made to ensure that you could switch out the microcontroller with something else should you want to spin up a customized version.

The whole idea reminds us a bit of quadcopters we’ve seen in the past, where the PCB wasn’t just being used structurally as a place to bolt the motors and hardware to, but actually contained functional traces and components that reduced how much wiring you needed to do. Naturally, this means that any damage to the chassis might cripple the electronics, but presumably, that’s what the big foam bumpers are there for.

[Dimitris] designed this project for educational use, so he assumes you’ll want to build 10 or 12 of these for your whole classroom. In those quantities, he says each bot will cost around $60. If you wanted to reduce the price a bit more, he says swapping the motors would be your best bet as they’re the single most expensive component of the design. That said, $60 for a quality open source rover platform sounds pretty fair to us.

Still too much? You could check out one of the 3D printable rover designs we’ve covered over the years. Or see if you can get lucky and pick up a cheap robot from the clearance rack and hack it.

Generate Power As You Ride With A Bicycle Planar Alternator

For most riders, bicycle lighting consists of an array of LED lamps and flashing gizmos, usually powered by lithium-ion batteries, or coin cells for the smaller ones. Some people though prefer to dispense with batteries and generate their own power, and that’s what [Thomas D] has done by fitting his bike with an alternator. But this is no off the shelf unit that rubs the tire or sits in a wheel hub. Instead, he’s built his own planar alternator that attaches to the spokes.

The design is inspired by those used in some wind generators, a central disk holding a set of planar coils sits between two rotating disks holding magnets. The stator holding the coils is made from laser-cut acrylic, and the rotors holding the magnets are sheet steel. One rotor is attached to the rear wheel spokes of the bicycle in close proximity to the stator which is attached to the rear frame. The second rotor sits on the other side of the stator while attached to the first rotor by its edge.

The coils are wired as two parallel groups in series in a ring with a single-phase output that feeds a rectifier and DC to DC converter. It would be interesting to see the effect of the same alternator with different winding arrangements or multiple phases.

This is the first time we’ve seen one of these on a bicycle, but this type of alternator has appeared here in more than one wind generator.

Continue reading “Generate Power As You Ride With A Bicycle Planar Alternator”

A Minimal ESP8266 Digital Picture Frame

Over the last few years, the price of a good digital picture frame has dropped to the point that we don’t often see DIY versions anymore. As much as we might hate to admit it, it’s hard to justify building something yourself when the economies of scale have made it so you can buy the final product for less than the cost of the parts themselves. But of course, there are always fringe cases where building it might be the only way to get what you need.

Granted we’re not sure that [Tony Liu] actually needs a 1.8-inch digital picture frame, but we’re sure somebody out there does. The ST7735R display used in this project is a real TFT, so the color and refresh rate is pretty good; but with a resolution of just 128×160, we’d recommend keeping your expectations low in regards to visual fidelity.

What’s really interesting about this project is how low the part count is. All you need is the ST7735R display and the ESP8266 itself (or the development board of your choice, naturally). Even the 3D printed frame is technically optional. The display is driven by SPI, so with the power added in, that’s only eight wires that need to be soldered between the two devices. If you’re looking for an easy way to add a photo slideshow to a small device, say a conference badge, this is about as easy as it gets.

But where are the images coming from? You might think SPIFFS, but in this case [Tony] has converted the images to bitmaps and is loading them into the Arduino Sketch as a header file with PROGMEM. Helpfully, he provides the link for the tool he uses to convert the images into an array the graphics library can understand. This makes adding new images slightly time consuming, but we imagine if you have the need for something like this, it’s probably only showing a pretty specific set of images anyway.

If you’re looking for something bigger, or maybe just an excuse to put that dusty Raspberry Pi to use, you might be interested in one of the more substantial builds we’ve seen over the years.

Continue reading “A Minimal ESP8266 Digital Picture Frame”

Never Miss A Doorbell With This Notifier

[PatH] tells us that he tragically missed a craft beer delivery to his home, and vowed never to let this happen again. His problem was that he’d missed the doorbell, resulting in one of those annoying notes from the delivery guy. His solution? An ESP8266-driven doorbell detector, that both sends him an SMS and records each doorbell press to a Google Sheet.

The doorbell detection is surprising but simple and non-intrusive, instead of running a GPIO line through some kind of interface to the button itself he’s added a reed switch to his ESP8266 board and used that to detect the magnetic field of the bell solenoids. It’s a convenient method, but one that only works with an old-style bell.

When the bell rings the magnetic field triggers the reed switch, and in turn the sketch running on the ESP calls out to IFTTT which triggers both an SMS and a write to a Google Sheets document that records each doorbell activation.

The ESP8266 seems to be a popular choice with doorbell automatprs probably because of its built-in networking and low price, but it’s not the only option. This optocoupler-sensed effort for example uses a Particle Xenon.

Hackaday Links Column Banner

Hackaday Links: March 1, 2020

Talk about buried treasure: archeologists in Germany have – literally – unearthed a pristine Soviet spy radio, buried for decades outside of Cologne. While searching for artifacts from a Roman empire settlement, the archeologists found a pit containing the Soviet R-394KM transceiver, built in 1987 and apparently buried shortly thereafter without ever being used. It was found close to a path in the woods and not far from several sites of interest to Cold War-era spies. Curiously, the controls on the radio are labeled not in Cyrillic characters, but in the Latin alphabet, suggesting the radio was to be used by a native German speaker. The area in which it was found is destined to be an open-cast lignite mine, which makes us think that other Cold War artifacts may have fallen victim to the gore-covered blades of Bagger 288.

Good news for Betelgeuse fans, bad news for aficionados of cataclysmic cosmic explosions: it looks like the red giant in Orion isn’t going to explode anytime soon. Betelgeuse has been dimming steadily and rapidly since October of 2019; as a variable star such behavior is expected, but the magnitude of its decline was seen by some astronomers as a sign that the star was reaching the point in its evolution where it would go supernova. Alas, Betelgeuse started to brighten again right on schedule, suggesting that the star is not quite ready to give up the ghost. We’d have loved to witness a star so bright it rivals the full moon, but given the times we live in, perhaps it’s best not to have such a harbinger of doom appear.

If you plan to be in the Seattle area as the winter turns to spring, you might want to check out the Vintage Computer Fair Pacific Northwest. We visited back during the show’s first year and had a good time, and the Living Computers: Museum + Labs, where the event is held, is not to be missed. The Museum of Flight is supposed to be excellent as well, and not far away.

Mozilla announced this week that Firefox would turn on DNS over HTTPS (DoH) by default in the United States. DoH encrypts the DNS requests that are needed to translate a domain name to an IP address, which normally travel in clear text and are therefore easily observed. Easily readable DNS transactions are also key to content blockers, which has raised the hackles of regulators and legislators over the plan, who are singing the usual “think of the children” song. That DoH would make user data collection and ad-tracking harder probably has nothing to do with their protests.

And finally, sad news from California as daredevil and amateur rocketeer “Mad” Mike Hughes has been killed in a crash of his homemade rocket. The steam-powered rocket was to be a follow-up to an earlier, mostly successful flight to about 1,900 feet (580 m), and supposed to reach about 5,000 feet (1.5 km) at apogee. But in an eerily similar repeat of the mishap that nearly killed Evel Knievel during his Snake River Canyon jump in 1974, Mike’s parachute deployed almost as soon as his rocket left the launch rails. The chute introduced considerable drag before being torn off the rocket by the exhaust plume. The rocket continued in a ballistic arc to a considerable altitude, but without a chute Mike’s fate was sealed. Search for the video at your own peril, as it’s pretty disturbing. We never appreciated Mike’s self-professed Flat Earth views, but we did like his style. We suppose, though, that such an ending was more likely than not.