Hackaday Prize Entry: Nuclear Powered Random Number Generator

August 16, 2015 by Will Sweatman 42 Comments

Random number generators come in all shapes and sizes. Some are software based while others, known as true random number generators, are hardware based. These can be created from thermal noise, the photoelectric effect and other methods. But none of these were good enough for [M.daSilva]. He would base his off of the radioactive decay of Uranium 238, and construct a working nuclear powered random number generator.

Because radioactive decay is unpredictable by nature, it makes for an excellent source for truly random data. The process is fairly simple. A piece of old fiestaware plate is used for the radioactive source. Put it in a lead enclosure along with a Geiger tube. Then wire in some pulse shaping circuitry and a microcontroller to count the alpha particles. And that’s about it. [M.daSilva] still has to do some statistical analysis to ensure the numbers are truly random, along with making a nice case for his project. But all in all, it seems to be working quite well.

Be sure to check out the video for quick rundown of [M.daSilva’s] project. If randomness is your thing, make sure you check out entropy harvested from uninitialized RAM, and the story behind the NIST randomness beacon.

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Cozy Heat Control With An Arduino

August 16, 2015 by James Hobson 22 Comments

[George Dewar] and his wife live in a typical 1940’s house in New Zealand , which in case you didn’t know, have a little insulation in the ceiling… and nowhere else. Like most, they put up with the cold — but after having a baby, [George] decided it was time to start controlling the heat a bit better.

They have an electric oil radiator which works well, but isn’t very smart. It only has 6 settings — not very useful when you’re trying to stay at a certain temperature. First off, they looked into a plug-in thermostat controller, and found a cheap one called the HeaterMate. Unfortunately it left a lot to be desired. For example, it didn’t seem to have PID control at all — and for an oil radiator, when you turn it off… it’s still going to heat the room for a while. He also found that because of the high current load of a heater … the device would read a few degrees over room temperature when operating. Unperturbed, [George] took this opportunity to design and build his own PID thermostat controller instead. Continue reading “Cozy Heat Control With An Arduino” →

Tiny Robot Shakes Head At You In Disapproval

August 15, 2015 by Richard Baguley 5 Comments

If you don’t have enough things staring at you and shaking their head in frustration, [Sheerforce] has a neat project for you. It’s a small Arduino-powered robot that uses an ultrasonic distance finder to keep pointing towards the closest thing it can find. Generally, that would be you.

When it finds something, it tries to track it by constantly rotating the distance finder slightly and retesting the distance, giving the impression of constantly shaking its head at you in disappointment. This ensures that you will either unplug it or smash it with a hammer after a very short time, but you should read [Sheerforce]’s code first: it’s a great example of documenting this for experimenters who want to build something that offers more affirmations of your life choices.

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Arduino Radar Watches You Breathe

August 15, 2015 by Dan Maloney 14 Comments

We’ve all likely watched an episode of “Star Trek” and admired the level of integration on the sick bay diagnostic bed. With its suite of wireless sensors and flat panel display, even the 1960s imagining of the future blows away the decidedly wired experience of a modern-day ICU stay. But we may be getting closer to [Dr. McCoy]’s experience with this radar-based respiration detector.

[Øyvind]’s build, which takes the origin of the term “breadboard” to heart, is based on a not-inexpensive Xethru module, which appears to be purpose-built for detecting respiration. The extra-thick PC board seems to house the waveguides internally, which is a neat trick but might limit how the module can be deployed. The module requires both a USB interface and level shifter to interface the 2.8V levels of the module to the 5V Arduino Uno. In the video below, [Øyvind]’s prototype simply lights an RGB LED in response to the chest movement it detects, but there’s plenty of potential for development here. We’ve seen a laser-based baby breathing monitor before; perhaps this systems could be used to the same end without the risk of blinding your tyke. Or perhaps better diagnostics for sleep apnea patients than an intrusive night in a sleep study lab.

Clocking in at $249 for the sensor board and USB interface, this build is not exactly for the faint of heart or the light of wallet. But as an off-the-shelf solution to a specific need that also has a fair bit of hacking potential, it may be just the thing for someone. Of course if radar is your thing, you might rather go big and build something that can see through walls.

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Tricking A Car Stereo To Think Your Cellphone Is A Tapedeck

August 13, 2015 by Kevin Dady 25 Comments

When you have an older vehicle there’s not a lot of options in the stock stereo department, often a CD player and tape deck is what you get. When you want to play your tunes from your mobile what do you do? Buying an adapter, or a new head unit for that matter, isn’t any fun. So why not hack it? This isn’t just a mechanical marriage of a Bluetooth dongle and an elderly stereo. Some real work went into convincing the stereo that the BT receiver was the stock tape deck.

Attacking the outdated Cassette deck [kolonelkadat] knew that inside the maze of gears and leavers, most of it is moving around actuating switches to let the radio know that there is a tape inside and that it can switch to that input and play. Tricking the radio into thinking there is a tape inserted is handled by an Arduino. Using a logic analyzer [kolonelkadat] figured out what logic signals the original unit put out and replicating that in his Arduino code.

Audio is handled by the guts of a bluetooth speaker with the output redirected into the radio where the signal coming off the tape head normally would have been directed. Join us after the break for a couple of videos with all of the details.

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Arduino Powered Rubber Band Sentry Turret Is Not A Lie

August 13, 2015 by Al Williams 14 Comments

You know that guy in the next cube is sneaking in when you are away and swiping packs of astronaut ice cream out of your desk. Thanks to [Kevin Thomas], if you have an Arduino and a 3D printer, you can build a rubber band sentry gun to protect your geeky comestibles. You’ll also need some metric hardware, an Arduino Uno, and a handful of servo motors.

The video shows [Kevin] manually aiming the gun, but the software can operate the gun autonomously, if you add some sensors to the hardware. The build details are a bit sparse, but there is a bill of material and that, combined with the 3D printing files and the videos, should allow you to figure it out.

We couldn’t help but wish for a first person view (FPV) camera and control via a cell phone, so you could snipe at those ice cream thieves while hiding in the broom closet. On the other hand, if you got the gun working, adding the remote wouldn’t be hard at all. You probably have a WiFi FPV camera on your quadcopter that finally came out of that tree and there’s lots of ways to do the controls via Bluetooth or WiFi.

Not that you don’t have options. But here at Hackaday HQ, we have lots of rubber bands and not so many green pigs. If you’d rather shoot paintballs, be careful you don’t accidentally repaint the insides of your cube.

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It’s Time To Roll Your Own Smartwatch

August 12, 2015 by Kristina Panos 29 Comments

Giant wristwatches are so hot right now. This is a good thing, because it means they’re available at many price points. Aim just low enough on the scale and you can have a pre-constructed chassis for building your own smartwatch. That’s exactly what [benhur] did, combining a GY-87 10-DOF module, an I²C OLED display, and an Arduino Pro Mini.

The watch uses one button to cycle through its different modes. Date and time are up first, naturally. The next screen shows the current temperature, altitude, and barometric pressure. Compass mode is after that, and then a readout showing your step count and kilocalories burned.

In previous iterations, the watch communicated over Bluetooth to Windows Phone, but it drew too much power. With each new hardware rev, [benhur] made significant strides in battery life, going from one hour to fourteen to a full twenty-fours.

Take the full tour of [benhur]’s smartwatch after the break. He’s open to ideas for the next generation, so share your insight with him in the comments. We’d like to see some kind of feedback system that tells us when we’ve been pounding away at the Model M for too long. Continue reading “It’s Time To Roll Your Own Smartwatch” →