Although scientists have known about Ultra-High Energy Cosmic Rays (UHECRs) for years, nobody can pinpoint their origin. When these UHECRs hit the ground, however, they cause a widespread local disturbance called an air shower. This air shower is a wide dispersion of photons, muons, and electrons at sea level. The means of observing this air shower mandates a widespread geographic region for detecting them. One solution would be a very big detector. Physicists [Daniel] and [Michael] discovered an alternative to pricey hardware, though. By leveraging the CMOS sensors in our smartphones, they can borrow some CPU cycles on our phones to create a worldwide detector network.
According to their paper, the CMOS camera in our smartphones is sensitive to the spectrum of radiation induced by muons and photons from these air showers. With an app running on our phones, [Daniel], [Michael], and other scientists can aggregate the data from multiple detections in a similar region to better understand their origins.
If you’re concerned about CRAYFIS taking away from your talk or web-browsing time, fear not; it runs in the background when a power source has been detected, hopefully, when you are asleep. It’s not the first time we see scientists tap into our computing resources, but this is certainly an achievement made possible in only the last few years by the sensor-loaded smartphone that charges on many of our night stands. With over 1.5 billion smartphones active in the world, we’re thrilled to see a team cleverly leveraging a ubiquitous and already-well-distributed resource.
Love them or hate them, plenty of people around the world use QR codes on a daily basis. Since he thinks they’re pretty great, Hackaday reader [falldeaf] thought it would be cool to put together an automatic QR code generator to be used on web sites.
Inspired by the custom QR logo embedding work done by our own [Brian Benchoff], his dynamic QR code generator allows you to do the same thing, but with far less work. The code requires that you have PHP and the GD library installed on your server, but other than that his code does the rest.
All you need to do is call up the page and pass along a URL, optional caption text, optional image overlay (to add your logo to the center of the code), as well as an optional hash code for tracking traffic sources. The page spits out a png image that can be used on its own, or embedded in a blog, which is what [falldeaf] plans on using it for.
If QR codes are your thing, be sure to grab a copy of his code, it will certainly be a handy tool to have around.
Don’t you hate that feeling, the one you get when you have just realized that you have no clue where you may have left your keys? If you are unlucky enough to have lost them in a public place, odds are they are as good as gone. Pumping Station One member [celtwolf] thought it would be great if your keys could help someone contact you instantly upon finding them, so he created a key fob that did just that.
SMS can use a similar URI scheme as the “mailto” protocol we are all familiar with, so [celtwolf] generated a URI that would send a text to his mobile phone with the message “I found your keys!”. He generated a QR code from the URI, then etched it on a piece of acrylic using a laser cutter. He filled in the recessed portions with a dark polymer clay, baked it, then coated it with a layer of nail polish for added durability.
Now, if anyone finds his keys and takes a picture of the QR code with their smartphone, he will immediately receive a text letting him know they are safe and sound. What a great idea!
Gizmodo’s in-depth look at smartphone OSes provides you with the pros and cons of each, allowing you to make an educated decision, if you’re in the market for a phone that also has email, a web browser, a calendar, and a decent contacts manager. If you’re attracted to the open source Linux-based Android by Google, you’ll also have to keep in mind that there aren’t that many business features. Other contenders include the Blackberry by RIM, which is great for email, but is completely closed and proprietary. The Apple iPhone is very pretty but lacks some basic features. They cover Symbian, Windows Mobile, and Palm Garnet too. It’s certainly a handy guide since most people haven’t used all six.