Representation of cosmic light hitting a smartphone's screen.

Detect Cosmic Rays With Your Smartphone Using CRAYFIS

October 17, 2014 by 6 Comments

[Daniel Whiteson and Michael Mulhearn], researchers at the University of California, have come up with a novel method of detecting ultra-high energy cosmic rays (UHECR) using smartphones. UHECR are defined as having energy greater than 1018eV. They are rare and very difficult to detect with current arrays. In order to examine enough air showers to detect UHECR, more surface area is needed. Current arrays, like the Pierre Auger Observatory and AGASA, cannot get much larger without dramatically increasing cost. A similar THP Quarterfinalist project is the construction of a low-cost cosmic ray observatory, where it was mentioned that more detection area is needed in order to obtain enough data to be useful.

[Daniel Whiteson and Michael Mulhearn] and colleagues noted that smartphone cameras with CMOS sensors can detect ionizing radiation, which means they also will pick up muons and high-energy photons from cosmic rays. The ubiquitous presence of smartphones makes their collective detection of air showers and UHECR an intriguing possibility. To make all this happen, [Whiteson and Mulhearn] created a smartphone app called CRAYFIS, short for Cosmic RAYs Found In Smartphones. The app turns an idle smartphone into a cosmic ray detector. When the screen goes to sleep and the camera is face-down, CRAYFIS starts taking data from the camera. If a cosmic ray hits the CMOS sensor, the image data is stored on the smartphone along with the arrival time and the phone’s geolocation. This information is uploaded to a central server via the phone’s WiFi. The user does not have to interact with the app beyond installing it. It’s worth noting that CRAYFIS will only capture when the phone is plugged in, so no worries about dead batteries.

The goal of CRAYFIS is to have a minimum of one million smartphones running the app, with a density of 1000 smartphones per square kilometer. As an incentive, anyone whose smartphone data is used in a future scientific paper will be listed as an author. There are CRAYFIS app versions for Android and iOS platforms according to the site. CRAYFIS is still in beta, so the apps aren’t publicly available. Head over to the site to join up!

[via Science]

ChipKIT Powered Electronic Dice

Electronic Dice Replaces Human Influence

October 17, 2014 by 44 Comments

[Will] likes his board games but can’t seem to keep from loosing the dice. He’s been using a dice-rolling smartphone app for a while now and decided that it was time to make a dedicated microcontroller dice roller.

The brain behind the dice roller is a chipKIT uC32 microcontroller. Seven output pins are connected to 7 appropriately-arragned LEDs in the top of the dice. There is only one more electrical component, a momentary switch, that is used to re-roll. When the button is pushed, a random number between 1 and 6 is generated and then displayed via the LEDs in true dice fashion. [Will] wrote his own code for this project and makes it available for anyone to download. The case is 3D printed and was designed in Tinkercad, the files of which are also available. The chipKIT is attached to the 3D printed base by a pair of zUNO clips. Find a short video of this thing in action after the break….

Digging the randomness of the roll but miss the realness of the dice? Check out this real dice roller. Need two electronic dice? Check these.

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The DIY Open Crank Engine Moped

October 16, 2014 by 50 Comments

Anyone can strap a two-stroke engine on a bicycle to create a moped. But [robinhooodvsyou] has created something infinitely more awesome. He’s built an inverted open crank engine on a 10 speed bicycle. (YouTube link)  As the name implies, the engine has no crankcase. The crankshaft, camshaft, and just about everything not in the combustion chamber hangs out in the open where it can be seen and appreciated.

[robinhooodvsyou] started with an air-cooled Volkswagen cylinder. He filled the jug with a piston from a diesel car. Camshaft, flywheel, valves, and magneto are courtesy of an old Briggs and Stratton engine. The cylinder head, crankshaft, pushrods, and the engine frame itself are all homemade.

Being an open crank engine, lubrication is an issue. The crankshaft’s ball bearing is lubricated by some thick oil in a gravity fed cup. Even though the engine is a four-stroke,[robinhooodvsyou] adds some oil to the gas to keep the rings happy. The camshaft and connecting rod use Babbit bearings. While they don’t have an automatic oiling system, they do look pretty well lubricated in the video.

Starting the engine is a breeze. [robinhooodvsyou] created a lever which holds the exhaust valve open. This acts as a compression release. He also has a lever which lifts the entire engine and friction drive off the rear wheel. All one has to do is pedal up to cruising speed, engage the friction drive, then disengage the compression release.

We seriously love this hack. Sure, it’s not a practical vehicle, but it works – and from the looks of the video, it works rather well. The unmuffled pops of that low 4:1 compression engine reminds us of old stationary engines. The only thing we can think to add to [robinhooodvsyou’s] creation is a good set of brakes!

Continue reading “The DIY Open Crank Engine Moped” →

Gesture Controlled Quadcopter

Controlling A Quadcopter With Gestures

October 16, 2014 by 16 Comments

[grassjelly] has been hard at work building a wearable device that uses gestures to control quadcopter motion. The goal of the project is to design a controller that allows the user to intuitively control the motion of a quadcopter. Based on the demonstration video below, we’d say they hit the nail on the head. The controller runs off an Arduino Pro Mini-5v powered by two small coin cell batteries. It contains an accelerometer and an ultrasonic distance sensor.

The controller allows the quadcopter to mimic the orientation of the user’s hand. The user holds their hand out in front of them, parallel to the floor. When the hand is tilted in any direction, the quadcopter copies the motion and will tilt the same way. The amount of pitch and roll is limited by software, likely preventing the user from over-correcting and crashing the machine. The user can also raise or lower their hand to control the altitude of the copter.

[grassjelly] has made all of the code and schematics available via github.

kickstarter notifications

Kickstarter Monitor Will Brighten Your Day

October 16, 2014 by 16 Comments

Keeping up with a kickstarter campaign can be quite a task, especially if your project is real (looking at you, Scribble Pen!) and you’re trying to keep up with product fabrication and all the other logistics involved in bringing a product to market. [macetech] are currently in the middle of a campaign themselves and built a loud, bright alert system to notify them of any new kickstarter backers.

The project uses a LED marquee to display the current number of backers, but every time a new backer contributes to the project, a blindingly bright green arrow traffic signal is illuminated and a piezo speaker plays a celebration tune. All of these devices are controlled by an Arduino Yun which, with its built-in Atheros chipset, easily connects to the network and monitors the kickstarter page for changes.

[macetech] used some interesting hardware to get everything to work together. They used a USB-to-RS232 cable with and FTDI chip to drive the LED marquee and a PowerSwitchTail 2 from Adafruit to drive the power-hungry traffic signal. Everything was put together in a presentable way for their workshop and works great! All of the source code is available on their project page, and you can check out their RGB LED Shades kickstarter campaign too.

A betta fish swims in an MFC.

Microbial Fuel Cell With A Side Of Betta Fish

October 16, 2014 by 35 Comments

Move over, potato batteries: DIY microbial fuel cells are here to stay! A microbial fuel cell (MFC) is a device that uses bacteria in an anaerobic (oxygen-poor) environment to convert chemical energy into electricity. [drdan152] posted steps on how to make a soil-based MFC  with a neat twist: it’s also a fishbowl for a betta fish.

[drdan152] used soil from the wetlands, referred to as “muck.” This nutrient-rich soil provided a hearty supply of bacteria, especially Geobacter species, known for their uncanny ability to transport electrons outside their cells using bacterial nanowires. The proton exchange membrane (PEM) was made up of salt, water, and agar. After some initial runs, [drdan152] determined that flat char cloth made the best anode, while red copper wire served as the cathode. Assembling the MFC was as simple as surrounding the anode with a thick layer of muck on all sides, adding the PEM on top, followed by water. The cathode was situated halfway out of the water.

After a couple of days, the voltage increased in proportion to the amount of bacteria growing on the anode. The betta fish can happily live in this habitat for a short period of time(it still has to be fed, of course), and the bacteria certainly won’t mind – the fish’s excrement provides an additional food supply. As a bonus, the water is kept clean. However, like any aquarium, the water will need to be changed periodically as carbon dioxide byproduct accumulates from the fish’s respiration and the MFC (high carbon dioxide levels = dead betta fish).

The MFC generates 725 mV. [drdan152] is not satisfied with that number, and is testing out charge pump circuits to generate as much as 3V. We are looking forward to seeing the results. We also wonder if a small aquatic plant could help make it a more self-sustaining environment for the fish. In the meantime, [drdan152] is encouraging others to try larger-scale versions of this MFC. Perhaps MFC-powered carnivorous robots doubling as mobile aquariums are in our near future.

A breakdown of the various parts of the Game Tin

Game Tin: Handheld Games With No Batteries

October 16, 2014 by 54 Comments

Anyone who grew up with a Game Boy knows how well they sucked through AA batteries. [Nick]’s Game Tin console solves this problem by running of an ultracapacitor charged by solar power.

The console is based on a EFM32 microcontroller: an ARM device designed for low power applications. The 128×128 pixel monochrome memory display provides low-fi graphics while maintaining low power consumption.

There’s two solar cells and a BQ25570 energy harvesting IC to charge the ultracap. This chip takes care of maximum power point tracking to get the most out of the solar cells. If it’s dark out, the device can be charged in about 30 seconds by connecting USB power.

The 10 F Maxwell ultracapacitor can run a game on the device for 1.5 hours without sunlight, and the device runs indefinitely in the sun. Thanks to the memory display, applications that have lower refresh rates will have much lower power consumption.

The Game Tin is open source, and is being developed using KiCad. You can grab all the EDA files from Bitbucket. [Nick] is also gauging interest in the Game Tin, and hopes to release it as a kit.