Interview With The Creators Of CHIP, A $9 Single-Board Computer

Single-board computing is hot on the DIY scene right now and riding that knife edge is C.H.I.P., a project currently in crowd-funding which prices the base unit at just $9. I was happy to run into the crew from Next/Thing Company who developed C.H.I.P. They were happy because, well, the project’s reception has been like a supernova. Right now they’re at about $1.5M of their original $50k goal. We spoke about running Linux on the board, what connectors and pinout headers are available, as well as the various peripheral hardware they have ready for the board.

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Retrotechtacular: Firepower For Freedom

As the United States were settled, its leaders found that they needed firepower to preserve freedom. This became especially apparent during the military engagements of the era, so a number of specialized facilities were founded to manage the research, development, manufacture, and dissemination of different types of munitions.

Picatinny Arsenal in New Jersey was the place for both nuclear and conventional weapon development. The men and women working in this facility created anti-personnel devices, including a flexible, adhesive charge called Flex-X that could be affixed to almost anything. This demolition charge could be layered for increased power, and could even detonate underwater. Picatinny also developed new rocket engines, propellants, and liquid propulsion for projectiles.

In Pennsylvania, a small-arms ammunition plant called Frankford Arsenal developed a duplex rifle cartridge. That is, a lead projectile fires on target, and a second one sitting behind it in the cartridge shoots at an angle, landing an inch or so near the lead bullet. Frankford workers also ground precision optics for target sighting and centering, and developed a case-less cartridge. Propellants geared for a wide variety of uses also came out of Frankford. These propellants were employed to deliver nerve agent antidotes, inflate life rafts quickly, and eject pilots from sketchy situations.

The Edgewood Arsenal in Baltimore specializes in the research and development, manufacture, and supply of chemical weapons. They are particularly adept at fire suppression. Edgewood research has provided civilian benefits as well, such as an anthrax vaccine. In addition, Fort Detrick, Maryland contains a biological R&D wing where vital antidotes and vaccines are developed.

All of this R&D and manufacture was orchestrated by the Ammunition Procurement and Supply Agency (APSA) located near Joliet, IL. In addition to reviewing all contractor bids with equal consideration, APSA controlled distribution, maintaining inventory on large computers that could crunch numbers like nobody’s business.

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Turning A Page With Your Voice

[Justin]’s friend [Steve] injured his spine a while ago, and after asking what would make [Steve]’s life simpler, the answer was easy. [Steve] missed reading books. Sure, e-readers exist, but you still need to turn the page. Now [Steve] can do that with his voice thanks to some microcontrollers, Bluetooth modules, and a voice recognition module.

A voice-activated page turner wasn’t the first attempt at giving [Steve] the ability to turn a page on a Kindle. The first prototype was a big blue button that sent a keyboard code for ‘right arrow’ over Bluetooth, turning a book one page at a time. This worked well until multiple pages turned, and with no back button it was a major nuisance.

After playing with the voice recognition in an Amazon Echo, [Steve] and [Justin] wondered if the same voice recognition technology could be applied to page turns on a Kindle. With a voice recognition Arduino shield from SparkFun it was easy to detect a ‘page down’ command. A Bluetooth module sends HID commands to a Kindle, allowing [Steve] to read a book with only his voice.

[Justin] put all the design files for this build up on Github.

Real Time Video Anonymizer

If you’re wondering, Cornell is just like every other university in one respect: the grad students are starving, and wherever there is free food, students circle like vultures. The engineering and CS departments have a mailing list alerting people to free food, but a more automated solution was desired. The first web cam ever was used to notify grad students if a coffee pot was full, but Cornell shot down this idea on the basis of privacy concerns.

It’s final project time for [Bruce Land]’s courses, and a project by [Ferian Chen] and [Sean Ogden] solved the privacy concerns of a webcam in a kitchen. It’s a real-time video anonymizer, that can also be used to livestream ransom demands if you’re so inclined.

There are actually two parts to this project. The first part pixellates faces and any other skin tone, just like you’d see on a true crime TV show. This part of the project was based on an FPGA-based face detection project. ‘Skin’ pixels are defined as having a difference between the red and green channels within a certain range. With the right lighting, it works very well.

You can identify someone with their voice, too, so [Ferian] and [Sean] also made efforts to disguise hungry student’s voices as well. This was done with a phase vocoder that changes the pitch of someone’s voice, but not the spectral characteristics. The result should have been an audio channel that can’t be pinned down to one person, but is still recognizable as speech. The audio processing didn’t work as intended, with noticeable artifacts in the output. There’s still some work to be done, and now that [Ferian] and [Sean] aren’t checking the kitchen every ten minutes, the might have the time to do it.

An Open Source, DIY Digitizer

When you look at the current methods of scanning 2D and 3D objects available today, you’re basically looking at an imaging process. Either you take a picture of a 2D object, or you grab a blob of point clouds with a 3D scanner and make a 3D object that way. It wasn’t always like this – real, hardware 3D digitizers were used all the way back in the 70s, and touch probes are standard equipment on high-end CNC machines.

[Nikolaj Møbius] needed a way to record points in physical space, and not wanting to deal with the problems of images, he made an open source DIY digitizer. It’s basically a laser cut arm with rotary encoders at each joint. By reading the rotary encoders with an Arduino, [Nikolaj] can digitize a few points on a workpiece – just enough to make a bracket, or find the critical dimensions of a part.

It’s a great tool for when you need a little more information than a set of calipers can provide, and a great example of some ancient tech made useful again.

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Hackaday Prize Entry: Density Altitude Gauge

Despite what extraordinarily overpowered quadcopters suggest, the air pressure of whatever a flying machine flys at is extremely important. Pressure is dependent on altitude and temperature, and there are hundreds of NTSB investigations that have concluded density altitude – pressure altitude corrected for nonstandard temperature variations – was the reason for a crash. Normally density altitude is computed through a slide rule or a flight computer, with the pilot entering in altitude and temperature, but somehow accidents still happen. For his entry to The Hackaday Prize, [Neil McNeight] is building an automated density altitude calculator to automate the process entirely.

Instead of having a pilot enter the altitude and temperature into a flight computer manually, [Neil]’s device grabs the current altitude from a GPS unit, and reads the temperature with a tiny sensor acquired from SparkFun. With just a little bit of math, this device will spit out the altitude an airplane or ‘copter thinks it’s at.

While the FAA won’t allow instruments that are cobbled together on a breadboard, this does have a few applications in the RC world. There are extremely high performance racing quadcopters out there now, and knowing how the craft will perform before flying it will save a few props.


The 2015 Hackaday Prize is sponsored by:

An Introduction To Valve’s Tracking Hardware

[Alan Yates] brought a demo of Valve’s new VR tech that’s the basis of the HTC Vive system to Maker Faire this year. It’s exceptionally clever, and compared to existing VR headsets it’s probably one of the best headtracking solutions out there.

With VR headsets, the problem isn’t putting two displays in front of the user’s eyes. The problem is determining where the user is looking quickly and accurately. IMUs and image processing techniques can be used with varying degrees of success, but to do it right, it needs to be really fast and really cheap.

[Alan] and [Valve]’s ‘Lighthouse’ tracking unit does this by placing a dozen or so IR photodiodes on the headset itself. On the tracking base station, IR lasers scan in the X and Y axes. By scanning these IR lasers across the VR headset, the angle of the headset to the base station can be computed in just a few cycles of a microcontroller. For a bunch of one cent photodiodes, absolute angles and the orientation to a base station can be determined very easily, something that has some pretty incredible applications for everything from VR to robotics.

Remember all of the position tracking hacks that came out as a result of the Nintendo Wii using IR beacons and a tracking camera? This seems like an evolutionary leap forward but in the same realm and can’t wait to see people hacking on this tech!