Detect Cosmic Rays with Your Smartphone Using CRAYFIS

Representation of cosmic light hitting a smartphone's screen.

[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]

Android hack adds missing Chromecast button to Netflix app


We finally got our hands on a Chromecast over the weekend and we love it! But it wasn’t without a bit of a speed bump. Including a quick initial setup, we had a YouTube video playing in our living room about three minutes after the package hit our mailbox. But we spent the next twenty minutes feeling like a moron because we couldn’t get the Netflix app on an Android phone to cast the video. Turns out there is a bug in the Netflix app that doesn’t add the Chromecast icon for all devices.

The issue is that the newest version of the Netflix app isn’t pushed to all devices. A fix is on the way, but we’re not good at waiting. We used this technique to trick Netflix into thinking we have different hardware. Notice from the screenshots above that one lists our device as an LG-P769 manufactured by LGE. That’s how our /system/build.prop file originally looked. By using the BuildProp Editor app we changed those settings to Nexus S by samsung. After rebooting several of our apps were missing from the app drawer, including Netflix. But they all still worked hitting the Play Store for reinstallation and we now have no problem casting Netflix.

Android app review: ADSdroid gives you every datasheet, ever

A few months ago when I reviewed the Android electronic reference app ElectroDroid, I made the offhand remark that a front end app for would be a killer mobile electronic reference app. [András Veres-Szentkirályi] accepted my challenge and built ADSdroid, the unofficial Android app for You can check out my complete review after the break.

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Ohm Sense makes sense of resistor color bands

[Alex Busman]‘s first foray in iOS programming looks like a pretty useful tool. He came up with Ohm Sense, an iPhone app that will take a picture of a resistor and calculate the value based on the color bands. It’s a great tool that we wish we had when we were starting out. At 99 cents, the app is also much cheaper than the emotional cost of our relationship with Violet.

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Adding mobile control to your gardening

[The Cheap Vegetable Gardener] wanted to check in on his garden from the road so he wrote a control app for his WinPhone. The hardware work is already done; having been built and tested for quite some time.

The implementation comes in two parts, both shown in the chart above. The grow box is behind a firewall as you don’t want random folks turning on the water and grow lights on a whim. The first part of the interface takes care of this separation by providing a set of functions on the host machine. The second portion is the phone app itself which calls those functions and displays all the pertinent information from the status of the lights, heater, exhaust, and water pump, to the current temperature and humidity. He’s even used Google Charts to graph data over time. The app itself took about two hours to code with no prior experience, a testament to the level of approachability these tools are gaining.

LED suit lights up the night

When the tipline popped up with this LED suit, part two, by [Marc DeVidts] we were expecing a simple led version of the previously known EL coat.

Well we were right and wrong in the same instance. Correct in that like predictions, the outcome is stonking great. Wrong in that this suit far outpaces EL in abilities we weren’t expecting. Namely to start off, an iPhone app over WiFi dictates to some 200 Arduino multiplexed RGB LED modules to dance randomly or follow patterns; an accelerometer and microphone are also implanted to further some effects. And finally if the suit isn’t enough to make you giddy, his PCB and enclosure milling surely will. Catch a video of the entire setup after the break.

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Androidome: Monome for Android

[Ewan Hemingway] tipped us off about his new Android app, Androidome. This is the first one he’s turned out after going through our Android development tutorials. It combines an app running on his Android 2.1 device with a computer running Max/MSP 5. The two don’t needed to be tethered, they just need to be on the same wireless network. This won’t be the best solution if you’re doing live performances, as the buttons on the screen end up being quite small. But as you can see after the break, it’s a great way to get into working with the Monome interface and decide if you want to build a dedicated physical version of the tool.

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