A Gloriously Impractical Electromechanical Display

December 19, 2017 by Tom Nardi 28 Comments

For this year’s office holiday party, [Gavan Fantom] wanted to do something really special. Coworkers were messing with LEDs to come up with displays and decorations, but they lack that old-school feel of mechanical displays. He wanted to create something that had retro look of moving elements, but didn’t want to just recreate the traditional flip mechanism we’ve all seen over and over.

The mechanism to drive a single “pixel”.

What [Gavan] came up with is breathtakingly impractical 8×8 display that sounds as cool as it looks. Each “pixel” in the display is a 3D printed screw mechanism rotated by a hobby servo. As the pixel is rotated in its case, it becomes progressively more visible to the observer. The opacity of the pixel can even be adjusted by varying the degree of rotation, allowing for rudimentary display of grayscale images.

Each element in the display is made up of seven 3D printed parts and two nails, which the mechanism slides on to move forward and backward. An 8×8 display needs 64 elements, which means the entire display needs 64 servos, 128 nails, and a whopping 448 3D-printed parts. Even with two printers attacking the production in parallel, the printing alone took over two weeks to complete.

The display is powered by a Raspberry Pi and three “Mini Maestro” controllers which can each handle 24 servos. [Gavan] found some sample code in Python to pass commands to the Maestro servo controllers, which he used as a template when writing his own software. The Python script opens image files, converts them to grayscale, and then maps the value of each pixel to rotation of the corresponding servo. He says the software is a little rough and that there’s still some calibration to be done, but we think the results are phenomenal so far.

Mechanical displays are a favorite of hackers, due in no small part to the awesome noises they make while in operation. While we’ve seen some very creative approaches to this type of display before, what [Gavan] has created here is certainly in a league of its own.

Continue reading “A Gloriously Impractical Electromechanical Display” →

Make Christmas Commercial Again With This Tiny TV Ornament

December 11, 2017 by Dan Maloney 11 Comments

Readers of a certain age will remember a time when the Christmas season in the US officially kicked off after Thanksgiving. That was when advertisers began saturation bombing the communal mind with holiday-themed TV commercials night and day. Broadcast TV no longer holds sway like it did back then, and advertisers now start their onslaught in September, but you can put a little retro-commercialism back to Christmas with this 90s Christmas commercial-playing ornament for your tree.

The idea came to [SeanHodgins] after stumbling upon a collection of Christmas commercials from the 1990s on YouTube. With his content identified, he set about building a tree-worthy display from a Pi Zero W and a TFT LCD display. An audio amp and tiny speaker from an old tablet and a LiPo battery and charger form the guts of [Sean]’s TV, which were stuffed into a 3D-printed TV case, appropriately modeled after the TV from The Simpsons. The small fresnel lens that mimics the curved screens of yore is a nice touch. The software has some neat tricks, such as an HTTP server that accepts the slug of a YouTube video, fetches the MP4, and automatically plays it. We prefer our Christmas tree ornaments a little quieter, so a volume control would have been nice, but aside from that this looks like a ton of fun.

This isn’t [Sean]’s first foray into tricked-out ornaments, of course; readers might recall his IoT cheer-measuring Christmas ornaments from last season.

Continue reading “Make Christmas Commercial Again With This Tiny TV Ornament” →

Woman Gets Diabetes, Builds Own Pancreas

December 6, 2017 by Will Sweatman 64 Comments

For the most part, when we break out the soldering iron to make a project for ourselves – we do so for fun. Sometimes we do so for necessity. Rarely do we, however, do so to save our own lives. [Dana Lewis] is one of the 30 million people in the US who suffer from diabetes. It’s a condition where the pancreas fails to make insulin, resulting in a buildup of sugar in the bloodstream. Managing the levels of insulin and sugar in their bodies is a day-to-day struggle for the millions of diabetics in the world. It’s a great deal more for [Dana], however. She sleeps with machines that monitor the glucose levels in her blood, but lives with constant worry.

“I was afraid at night because I am a super-deep, champion sleeper,” Lewis said, “I sleep through the alarms on the device that are supposed to wake me up and save my life…”

What she needed was the glucose data from the device and use it to trigger a louder alarm. It wasn’t long until she found someone who had done just this. Using a Raspberry Pi, she was able to capture the data and then alarm her via her phone. She then setup a web interface so others could see her data and call her if she didn’t wake.

The next step is obvious. Why not make the state of the insulin pump a function of the data? And thus, a sort of artificial pancreas.

The project is open source for anyone to use and improve upon. She was placed on a list for the 100 most creative people in the US for 2017. We’re not strangers to the idea of an artificial pancreas, but it’s always great to see people using things we make video game consoles out of to save lives.

Thanks to [Dave Zzzz] for the tip!

Astro Cat: Raspberry Pi Telescope Controller

December 5, 2017 by Tom Nardi 8 Comments

When somebody tackles an engineering problem, there are two possible paths: they can throw together a quick and dirty fix that fits their needs (the classic “hack”, as it were), or they can go the extra mile to develop a well documented solution that helps the community as a whole. We cover it all here at Hackaday, but we’ve certainly got a soft spot for the latter approach, even if some may feel it falls into the dreaded territory of “Not A Hack”.

When [Gary Preston] wanted to control his telescope and astrophotography hardware, he took the second path in a big way. Over the course of several posts on his blog, [Gary] walks us though the creation of his open source Raspberry Pi add-on board that controls a laundry list of sensors and optical gear. Just don’t call it a HAT, while it may look the part, [Gary] is very specific that it does not officially meet the HAT specifications put out by the Raspberry Pi Foundation.

Even if you aren’t terribly interested in peering into the infinite void above, the extremely detailed write-up [Gary] has done contains tons of multidisciplinary information that you may find useful. From showing how to modify the Pi’s boot configuration to enable true hardware UART (by default, the Pi 3 ties it up with Bluetooth) and level shifting it with a ST3232 to a breakdown of the mistakes he made in his PCB layout, there’s plenty to learn.

Astro CAT is a completely open source project, with the hardware side released under the CERN Open Hardware License v1.2, and the INDI driver component is available under the GPL v3.

If this looks a bit daunting for your first stab at astrophotography with the Raspberry Pi, fear not. We’ve covered builds which can get you up and running no matter what your budget or experience level is.

Classic Tomy Toy Gets AIY Makover

December 4, 2017 by Jenny List 5 Comments

A few months ago the Raspberry Pi magazine The MagPi gave away a piece of hardware, the Google AIY voice control kit. Subscribers all received one, but as always the eBay scalpers cleaned up all the in-store copies and very few lucky enthusiasts scored a kit of their own.

Among these frustrated Pi owners was [Circuitbeard], who decided instead to make his own kit. And since a cardboard case lacked style, he decided to do so in the shell of a 1980s Tomy Mr. Money toy novelty bank. Into it went a Raspberry Pi Zero W and an audio pHat, with a servo to operate the head and a microswitch connected to the toy’s arm as a trigger.

The Python code to run everything is all included in the write-up, and he’s posted a video of the device in operation which we’ve placed below the break.

Continue reading “Classic Tomy Toy Gets AIY Makover” →

Meet The Modern Meat Man’s Modified Meat-Safe

December 3, 2017 by Lauren Faris 5 Comments

Charcuterie is delicious — but is it hackable? When talking about the salty preserved meats, one might be more inclined to indulge in the concept of bacon before pondering a way to integrate an electrical monitoring system into the process. However, [Danzetto] decided to do both when he did not have anywhere to cure his meats. He made his own fully automatic meat curing chamber lovingly called the curebOS with the aid of a raspberry pi. It is basically a beefed up mini fridge with all of the bells and whistles.

This baby has everything. Sitting on top is a control system containing the Pi. There are 5 relays used for the lights, circulating fan, ventilating fans, refrigerator, and humidifier all powered by a 5 amp supply — minus the fridge. Down below that is the 3D printed cover with a damper for one of the many ventilation fans that regulate the internal temperature. To the right is a touchscreen for viewing and potentially controlling the system if necessary. The control program was written in Python for viewing the different trends. And below that, of course, is a viewing window. On the inside are temperature and humidity probes that can be monitored from the front screen. These readings help determine when to activate the compressor, any of the fans, or the humidifier for optimal settings. For a final touch, there are also some LEDs placed above the hanging meat to cast a glowing effect upon the prized possessions.

Continue reading “Meet The Modern Meat Man’s Modified Meat-Safe” →

Solving A Rubik’s Cube With Just Two Motors

December 2, 2017 by Dan Maloney 11 Comments

We’ve all seen videos of Rubik’s cube champions who can solve the puzzle in less than 5 seconds. And there are cube-twisting robots that can solve the cube even faster, often in under a second. This Rubik’s cube solver is not one of those robots, but it’s still pretty cool.

The reason we like Dexter Industries’ “BricKuber” is not for its lightning speed — it takes a minute or two to solve the puzzle. What we like is the simplicity of the approach to manipulating the cube. Built from LEGO parts, including Mindstorms motors and a BrickPi controller, the BricKuber uses only two motors to work the cube. One motor powers a square turntable upon which the cube sits, while the other powers an arm that does double duty — it either clamps the cube so the turntable can rotate a layer, or it rakes the cube to flip it 90° on the turntable. With a Pi Cam overhead, the rig images all six faces, calculates a solution to the cube, and then flips and twists the cube to solve it. It’s simultaneously mind-boggling and strangely relaxing to watch.

All the code is open source, and we strongly suspect a similar and possibly faster robot could be built without the LEGO parts. You might even be able to build one with popsicle sticks and an Arduino.

Continue reading “Solving A Rubik’s Cube With Just Two Motors” →