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Hackaday Prize Entry: A $100 CT Scanner

May 14, 2015 by 21 Comments

What do you do when you’re dad’s a veterinarian, dumped an old x-ray machine in your garage, and you’re looking for an entry for The Hackaday Prize? Build a CT scanner, of course. At least that’s [movax]’s story.

[movax]’s dad included a few other goodies with the x-ray machine in the garage. There were film cassettes that included scintillators. By pointing a camera at these x-ray to visible light converting sheets, [movax] can take digital pictures with x-rays. From there, it’s just building a device to spin around an object and a lot – a lot – of math.

Interestinly, this is not the first time a DIY CT scanner has graced the pages of Hackaday. [Peter Jansen] built a machine from a radiation check source, a CMOS image sensor, and a beautiful arrangement of laser cut plywood. This did not use a proper x-ray tube; instead, [Peter] was using the strongest legally available check source (barium 133). The scan time for vegetables and fruit was still measured in days or hours, and he moved on to build an MRI machine.

With a real source of x-rays, [movax]’s machine will do much better than anything the barium-based build could muster, and with the right code and image analysis, this could be used as a real, useful CT scanner.

The 2015 Hackaday Prize is sponsored by:

Hackaday Prize Entry: A 7805 Replacement

May 13, 2015 by 75 Comments

The 7805 voltage regulator is a great device if you want a simple way of bringing a voltage down to 5V. It’s a three-pin, one-component solution that puts out five volts and a lot of heat. Simple, not efficient. For his Hackaday Prize entry, [K.C. Lee] is working on a much more efficient drop-in replacement for the 7805.

Linear regulators like the 7805 are great, but they’re not terribly efficient. Depending on the input voltage you might see 50% efficiency. Going to a switch mode supply, that efficiency shoot up to about 90%.

For his drop-in replacement, [K.C. Lee] is using the LM3485, a switch mode regulator that only needs a few extra parts to turn it into a replacement for the 7805. You will need a cap on the input, but you should already be putting those in your circuit anyway, right?

The 2015 Hackaday Prize is sponsored by:

Racing The Beam With Super Hexagon

May 13, 2015 by 24 Comments

Early game consoles like the Atari 2600 had a very, very limited amount of RAM. There wasn’t even enough RAM for all the pixels on the screen; instead, pixels were generated by the CPU as they were being drawn. It’s playing with scanlines and colorbusts with code, something we’re now calling. ‘racing the beam’ for some reason.

[Sam] is in the middle of an EE degree right now, and for a digital design class he needed to write some Verilog. At the time he was addicted to the game Super Hexagon, and the game mechanics are simple enough for an FPGA. He built his own implementation, but not one with framebuffers. He’s using a pipelined approach where each pixel’s value is calculated just a few clock cycles before it’s displayed. It vastly reduces the memory requirements, on his Altera DE1 board compared to the framebuffer approach.

Video below.

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Hackaday Prize Entry: A Pic32 Game Console

May 12, 2015 by 5 Comments

The official theme of the 2015 Hackaday Prize is to build something that matters. Solving the challenges facing the world is hard, and retro video games, despite what you read on Hackaday, do not matter.

That doesn’t mean there’s not space for the weird, esoteric builds out there; we have a best product prize that will dump $100k, a six month residency in the Hackaday Design Lab, and contacts with a lot of engineers with expertise in manufacturing. [Alex]’s extremely ow cost game console on a Pic32 is exactly what this prize category is looking for.

[Alex]’s project – XORYA – is based on the Pic32MX170F256, a chip that runs up to 50MHz, has 256kB of flash, and a full 64k of RAM. This is far beyond what the guys at Atari imagined back in the 70s, allowing the XORYA to have some amazing graphics.

Right now most of the build is dedicated to fleshing out the video system, and [Alex] has a great demo: rendering the Mandelbrot set in real time in 16 colors on an NTSC display with a resolution of 160×100. That’s a single-chip game console that’s right up there with the Uzebox, and a great example of the potential of the best product category for this year’s Hackaday Prize.

The 2015 Hackaday Prize is sponsored by:

Hackaday Prize Entry: Junkyard Fuel Cell

May 11, 2015 by 26 Comments

Modern hydrogen fuel cells are incredible pieces of engineering. While a simplistic diagram of a fuel cell is just a stream of hydrogen, an anode, cathode, and a bit of oxygen, this does’t convey the complexity of the most important part of the fuel cell – the proton exchange membrane.

The proton exchange membrane is the part of a fuel cell that takes in hydrogen, spits out electrons, and produces water. They can be made from platinum to expensive DuPont products, and if [Charlie]’s hypothesis is correct, stuff you can pull out of a junkyard.

The goal of [Charlie]’s Prize entry is to create a small, proof of concept fuel cell that’s safe, low cost, and very easy to build. Right now he’s focused on finding a cheap, readily available proton exchange membrane to make this build accessible to everyone.

A hydrogen fuel cell will of course have pressurized hydrogen in it, and [Charlie] is taking some steps to mitigate the risks of having his limbs blown off. His first real project update is about the safety considerations of working with hydrogen. He’ll be using a simple hydrogen gas sensor to measure for leaks and sound an alarm.

The 2015 Hackaday Prize is sponsored by:

Hackaday Prize Entry : Impact – A Head Concussion Monitor

May 10, 2015 by 30 Comments

A lot of young athletes who get concussions each year go undiagnosed, leading to brain injury. [Hunter Scott] is working on a device called Impact to help detect these events early. According to this article which discusses the issue of concussion recognition and evaluation, “Early identification on the sports sideline of suspected concussion is critical because, in most cases, athletes who are immediately removed from contact or collision sports after suffering a concussion or other traumatic brain injury will recover without incident fairly quickly. If an athlete is allowed to keep playing, however, their recovery is likely to take longer, and they are at increased risk of long-term problems”

The device is a dime sized disk, which has an ATTiny85 microcontroller, memory to hold data, an accelerometer and a LED which gets activated when the preset impact threshold is breached, all driven by a coin cell. This small size allows it to be easily embedded in sports equipment such as helmets. At the end of a game, if the LED is blinking, the player is then screened for a concussion. For additional analysis, data stored on the on-board memory can be downloaded. This can be done by a pogo-pin based docking station, which is what [Hunter Scott] is still working on.

He’s having a functional problem that needs fixing. The ATTiny85 cannot be programmed with the accelerometer populated. He first needs to populate the ATTiny85, program it, and then populate the accelerometer. He’s working in fixing that, but if you have any suggestions, chime in on the comments below. We’d like to add that [Hunter] is a prolific hacker. His project, the Ultra-wideband radio module was a Hackaday Prize semi-finalist last year.

The 2015 Hackaday Prize is sponsored by:

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Hackaday Links: May 10, 2015

May 10, 2015 by 9 Comments

Here’s a cool crowdfunding campaign that somehow escaped the Hackaday Tip Line. It’s a remote control SpaceShipOne and White Knight. SpaceShipOne is a ducted fan that has the high-drag feathering mechanism, while White Knight is a glider. Very cool, and something we haven’t really seen in the scratchbuilding world.

[Sink] has a Makerbot Digitizer – the Makerbot 3D scanner – and a lot of time on his hands. He printed something, scanned it, printed that scan… you get the picture. It’s a project called Transcription Error.

Keurig has admitted they were wrong to force DRM on consumers for their pod coffee cups.

The Apple ][, The Commodore 64, and the Spectrum. The three kings. Apple will never license their name for retro computer hardware, and there will never be another computer sold under the Commodore label. The Spectrum, though… The Sinclair ZX Spectrum Vega is a direct-to-TV console in the vein of [Jeri Ellisworth]’s C64 joystick doohickey.

Infinity mirrors are simple enough to make; they’re just one mirror, some LEDs, and another piece of glass. How about a 3D infinity mirror? They look really, really cool.

Here’s the six-day notice for some cool events: Hamvention in Dayton, OH. [Greg Charvat] will be there, and [Robert] is offering cold drinks to anyone who mentions Hackaday. If anyone feels like scavenging for me, here’s a thread I created on the Vintage Computer Forum.  Bay Area Maker Faire is next weekend. Most of the rest of the Hackaday crew will be there because we have a meetup on Saturday night