Car-Cade Build Drives Unthrottled Determination

November 30, 2017 by Kristina Panos 3 Comments

Remember those dashboard-shaped racing games from the ’80s, like Tomy Turnin’ Turbo? [Daniel] has long wanted to bring one of those into the modern age. After finding that someone beat him to it, he went in another direction and built his own mini-cabinet from the ground up, dedicated to Dirt Rally.

The idea was to build the smallest possible computer than can run SteamOS and fit inside of a cabinet printed on a Prusa clone. At first, [Daniel] tried driving a MinnowBoard around. The frame rate was atrocious, so he switched to an ASUS mini-STX board and went from there.

The printed steering wheel and throttle are both analog inputs—each uses a 10kΩ pot connected to a Pimoroni PiCade controller. We love [Daniel]’s lo-tech way of using rubber bands to self-center them. We also love the post-processing he did on the steering wheel to give it that just-right grippy feel (it’s Plasti-Dip rubber paint), because it looks fantastic.

The lovely blue cabinet is an homage to [Daniel]’s Dirt Rally destroyer of choice, the rally blue ’95 Subaru Impreza. He had an arduous print/sand/prime/paint plan all worked out for the prototype, but ultimately printed the parts in different colors to get the look right. [Daniel] went through four different blue filaments alone before he was satisfied.

Motor around the break for a quick walk around the completed cabinet, and park it for the teaser video that scored [Daniel] a swag bag from the Dirt Rally devs through the magic of social media. Now that it’s cold and flu season in the northern hemisphere, maybe you’d prefer to play driving games without touching anything.

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Rage Against The Dying Of The Light With A Raspi Night Vision Camera

November 29, 2017 by Kristina Panos 8 Comments

One of the most interesting things about hacking is the difference between the vision we have at the beginning and the reality of we’ve built at the end. What began as a simple plan to build a night vision VR headset turned into a five-month adventure for [facelessloser] that culminated in this great-looking camera. He thought it would be easy, but almost every aspect presented some kind of challenge. The important thing is that he kept at it.

One of the major issues [facelessloser] encountered was power. He found that the Pi (Zero W), the screen, and the IR LEDs draw between 1.5 and 2A altogether. He was able to solve this one by using the charging board from a 2A power bank paired with a 1200mAh Li-Po built for the high draw required by vaping. If not for space issues, he might have used a 18650 or two.

Another challenge he faced was storing the video and images. He’d considered setting up the Pi as an access point to view them from a phone browser, but ultimately extended a USB port with an OTG cable to use flash drives. With a bit of Python he can watch for the drive to mount and then write to it. If the flash drive suddenly disappears, the Pi starts saving to the SD card.

There are two videos after the break, a walk through and a night vision demo. You’ll see a bit of a lag happening in the demo video—that’s because [facelessloser] is running the feed through PyGame first. No matter what nightlife you want to peep, it might be nice to add automated zoom with a rangefinder or get a closer look with some PiNoculars.

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Roll Your Own Rotary Tool

November 22, 2017 by Kristina Panos 37 Comments

Rotary tools are great little handheld powerhouses that fill the void between manual tools and larger shop machines. They’re also kind of expensive for what they are, which is essentially a power circuit, a switch, and a high-RPM motor with a tool coupling on the shaft. If your tooling needs are few and you have the resources, why not make your own?

[DIY King 00] built himself a cordless rotary tool for less than $10 out of commonly-available parts. It doesn’t run nearly as fast as commercial rotary tools, but that’s not necessarily a bad thing. He made the body out of 2″ diameter PVC and mounted a 12 V, 400 RPM DC motor directly to one of the fiberglass end caps. Tools are chucked into a collet that screws into a coupler on the motor shaft.

For power, [DIY King 00] built a 7.4 V battery pack by wiring two 18650 cells from an old laptop battery in series. It isn’t the full 12 V, but it’s enough power for light-duty work. These 2200 mAh cells should last a while and are rechargeable through the port mounted in the other end cap.

Drill down past the break to see the build video and watch the tool power through plywood, fiberglass, and inch-thick lumber. Once you’ve made your own rotary tool, try your hand at a DIY cordless soldering iron.

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Joan Feynman Found Her Place In The Sun

November 21, 2017 by Kristina Panos 45 Comments

Google ‘Joan Feynman’ and you can feel the search behemoth consider asking for clarification. Did you mean: Richard Feynman? Image search is even more biased toward Richard. After maybe seven pictures of Joan, there’s an endless scroll of Richard alone, Richard playing the bongos, Richard with Arline, the love of his life.

Yes, Joan was overshadowed by her older brother, but what physicist of the era wasn’t? Richard didn’t do it on purpose. In fact, no one supported Joan’s scientific dreams more than he did, not even their mother. Before Richard ever illuminated the world with his brilliance, he shined a light on his little sister, Joan.

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Distributed Air Quality Monitoring Via Taxi Fleet

November 20, 2017 by Kristina Panos 11 Comments

When [James] moved to Lima, Peru, he brought his jogging habit with him. His morning jaunts to the coast involve crossing a few busy streets that are often occupied by old, smoke-belching diesel trucks. [James] noticed that his throat would tickle a bit when he got back home. A recent study linking air pollution to dementia risk made him wonder how cities could monitor air quality on a street-by-street basis, rather than relying on a few scattered stations. Lima has a lot of taxis, so why wire them up with sensors and monitor the air quality in real-time?

This taxi data logger’s chief purpose is collect airborne particulate counts and illustrate the pollution level with a Google Maps overlay. [James] used a light-scattering particle sensor and a Raspi 3 to send the data to the cloud via Android Things. Since the Pi only has one native UART, [James] used it for the particle sensor and connected the data-heavy GPS module through an FTDI serial adapter. There’s also a GPS to locate the cab and a temperature/humidity/pressure sensor to get a fuller environmental picture.

Take a ride past the break to go on the walk through, and stick around for the testing video if you want to drive around Lima for a bit. Interested in monitoring your own personal air quality? Here’s a DIY version that uses a dust sensor.

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Your Next Wearable May Not Need Electricity

November 17, 2017 by Kristina Panos 9 Comments

What if you could unlock a door with your shirtsleeve, or code a secret message into your tie? This could soon be a thing, because researchers at the University of Washington have created a fabric that can store data without any electronics whatsoever. The fabric can be washed, dried, and even ironed without losing data. Oh, and it’s way cheaper than RFID.

By harnessing the ferromagnetic properties of conductive thread, [Justin Chen] and [Shyam Gollakota] have proved the ability to store bit strings and 2D images through magnetization. The team used an embroidery machine to lay down thread in dense strips and patches, and then coded in ones and zeros by rubbing the threads with N and S neodymium magnets.

They didn’t use anything special, either, just this conductive thread, some magnets, and a Nexus 5 to read the data. Any phone with a magnetometer (so, most of them) could decode this type of binary data. The threads stay reliably magnetized for about a week and then begin to weaken. However, their tests proved that the threads can be re-magnetized over and over.

The team also created 2D images with magnets on a 9-patch made of conductive fabric. The images can be decoded piecemeal by a single magnetometer, or all at once by an array of them. Finally, the team made a glove with a magnetized patch of thread on the fingertip. They were able to get the phone to recognize six unique gestures with 90% accuracy, even with the phone tucked away in a pocket. See it in action in their demo video after the break.

Magnetic memory is certainly not a new concept. But for the wearable technology frontier, it’s a novel one.

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Get You An E-Textiles Sensor That Can Do Both

November 16, 2017 by Kristina Panos 10 Comments

[Admar] is a software developer who was introduced to e-textiles in 2011. The bug firmly took hold, and these days he gives e-textile workshops at Eindhoven University of Technology. Here, students learn to build a single e-textile sensor that detects both presence and pressure. The workshop presentations are available on his site, which is itself a window into his e-textile journey.

Over the years, [Admar] has discovered that any e-textile project requiring more than a few connections is ripe for some kind of textile-friendly multi-point connector. Through trial and error, he designed a robust solution for use with an embroidery machine. The wires are made from conductive thread and soldered to a row of male header pins to make the transition out of fiber space. This transition requires solder, which quickly gets interesting when coupled with a fabric substrate and no solder mask. We wonder if spraying on mask beforehand would help, or if it would just soak in and stain and get in the way.

You can see the connector in practice in [Admar]’s capacitive multi-touch demo video after the break. He has stacked two pieces of fabric, each with a wire bus made of conductive threads, with the traces at right angles. Both sensors are wired to a Cypress PSoC5 to create a sensor matrix, and then to a laptop for visualization purposes. As his fingers approaches the fabric, the bar graphs roar upward to show increased capacitance. Once he makes contact, each finger appears as a yellow dot illustrating pressure.

E-textile projects aren’t limited to traces sewn by hand or embroidery machine. Circuit boards can be knitted, too.

Thanks for the tip, [Melissa]!