The 2G Raspberry Pi Smartphone

For [Tyler]’s entry to the Hackaday Prize, he’s making something that just a few years ago would be unheard of in a homebrew build. He’s making a DIY smartphone. Yes, with cheap single-board Linux computers, GSM modules, and SPI touchscreen displays, it’s possible to build your own smartphone.

Inside [Tyler]’s DIY smartphone is a Raspberry Pi Model A, a 3.5 inch touchscreen PiTFT with 480×320 resolution, and an Adafruit FONA module The connections are simple enough; the TFT is connected over SPI, and the GSM module over serial. The entire device is powered by a 1200mAh LiIon battery, charged with a powerboost board, runs an operating system written in Python capable of making calls, sending texts, and takes pictures with a Pi camera.

This is not what you would normally call a smartphone. The FONA module is 2G only, meaning you’re limited to 2G speeds and 2G networks. AT&T will be shutting down 2G networks in a little bit, although T-Mobile will be keeping them up for anyone who still has an old Nokia Brick.

That said, [Tyler]’s phone is still exactly what you want in a minimal phone: it just makes calls and receives texts, it has a camera, and unlike the Nokia, you can take it apart and repair it easily. Not that you ever had to do that with a Nokia…

CRAYFIS Hijacks our Cellphones for a Worldwide Cosmic Ray Detector

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.

via [NPR]

Seeing The World Through Depth Sensing Cameras

The Oculus Rift and all the other 3D video goggle solutions out there are great if you want to explore virtual worlds with stereoscopic vision, but until now we haven’t seen anyone exploring real life with digital stereoscopic viewers. [pabr] combined the Kinect-like sensor in an ASUS Xtion with a smartphone in a Google Cardboard-like setup for 3D views the human eye can’t naturally experience like a third-person view, a radar-like display, and seeing what the world would look like with your eyes 20 inches apart.

[pabr] is using an ASUS Xtion depth sensor connected to a Galaxy SIII via the USB OTG port. With a little bit of code, the output from the depth sensor can be pushed to the phone’s display. The hardware setup consists of a VR-Spective, a rather expensive bit of plastic, but with the right mechanical considerations, a piece of cardboard or some foam board and hot glue would do quite nicely.

[pabr] put together a video demo of his build, along with a few examples of what this project can do. It’s rather odd, and surprisingly not a superfluous way to see in 3D. You can check out that video below.

Continue reading “Seeing The World Through Depth Sensing Cameras”

Detect Cosmic Rays with Your Smartphone Using CRAYFIS

[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]

Google Releases Project Ara MDK

Ara Modules


It’s been a little while since we’ve heard about modular smartphones, but Google has just released the Module Developers Kit (MDK) for Project Ara. The development kit gives an overview of the inner workings of the project, and provides templates for building your own modules.

Once you’ve agreed to the license agreement and downloaded the MDK, you’ll find a large specification document. It explains how a phone will comprise of many modules loaded into an endoskeleton, giving mechanical support and electrical connections. An interface block provides each module with power and data over LVDS. Modules are held in place by an electro-permanent magnet which can be toggled by software.

When you’re finished with the specification document, you can dive into the reference designs. These include templates and actual modules for WiFi, thermal imaging, a battery pack, and more. Mechanical CAD is provided as STEP files and drawings, and electrical design files are provided as Altium projects and PDF schematics.

We discussed both Project Ara and Phonebloks on Hackaday in the past, but now we’re starting to see real details. Google’s Project Ara Developer Conference takes place on April 15th and 16th, and you can register to take part remotely for free. Is this the start of an open, modular phone? Let us know what you think.

[Thanks to Adam for the tip]

Use Your Smartphone as a Microscope for Less Than $10

FY4TBHSHMMFBB4V.LARGE[Yoshinok] recently posted an Instructable on doing a $10 smartphone-to-microscope conversion. The hack isn’t so much a conversion as just a handy jig, but it’s still interesting. The basic idea is to set up a platform for the slides, and to mount the smartphone directly above. The trick, and the reason this can be called a microscope, is that [Yoshinok] embeds the lens from a cheap laser pointer into the smartphone holder. He is able to get 40x optical magnification with the lens, and even though it sacrifices quality, he uses the built-in digital zoom to get up to 175x magnification.

By itself, you could use this with a light source to magnify 3D objects. [Yoshinok] demonstrates this with a dime. But since the slide holder is made of clear acrylic, he mounted a cheap LED flashlight in the base to serve as through-sample lighting. Using this setup, he was able to observe the process of plasmolysis.

If you have kids, this is certainly a project to do with them, but we can’t help but think it will be useful for non-parents alike. This sort of magnification is good enough for simple lab experiments, and given that most Hack-a-Day readers have these parts lying around, we figure the cost is closer to $0. If you give it a try, let us know your results in the comments!

Continue reading “Use Your Smartphone as a Microscope for Less Than $10”

WeMo without a smartphone

[Matt Galisa] decided to try his hand at setting up the Belkin WeMo outlet without using a Smartphone app. The hardware is a pass-through for mains voltage which allows you to switch the plug over the network. It has a built-in WiFi module which normally connects to your home network. But the first time that you power it up it announces its own SSID designed for an iOS (and recently Android Beta) app to connect to in order to enter your AP credentials.

He started with this Python script used for WeMo hacking. It was originally meant to issue commands to the outlet once it had passed the initial setup. [Matt] followed along but couldn’t get an answer on the port he expected. It turns out that the device listens on a different port until the initial setup is complete (probably so that you don’t mess up other outlets on the network that are already working correctly). His next challenge was to manually set the WPA credentials. This never really worked and he ended up using a virtual AP without password protection through DD-WRT. From there he was able to set up a Python script to turn on, off, and toggle the state of the outlet.

If you’re looking to dig deeper into the device’s security check out this project.