Anyone who had a cheap set of computer speakers in the early 2000s has heard it – the rhythmic dit-da-dit-dit of a GSM phone pinging a cell tower once an hour or so. [153armstrong] has a write up on how to capture this on your computer.
It’s incredibly simple to do – simply plug in a set of headphone to the sound card’s microphone jack, leave a mobile phone nearby, hit record, and wait. The headphone wire acts as an antenna, and when the phone transmits, it induces a current in the wire, which is picked up by the soundcard.
[153armstrong] notes that their setup only seems to pick up signals from 2G phones, likely using GSM. It doesn’t seem to pick up anything from 3G or 4G phones. We’d wager this is due to the difference in the way different cellular technologies transmit – let us know what you think in the comments.
This system is useful as a way to detect a transmitting phone at close range, however due to the limited bandwidth of a computer soundcard, it is in no way capable of actually decoding the transmissions. As far as other experiments go, why not use your soundcard to detect lightning?
[Paul] has put together an insanely small yet powerful tracker for monitoring all the things. The USB TinyTracker is a device that packages a 48MHz processor, 2G modem, GPS receiver, 9DOF motion sensor, barometer, microphone, and micro-SD slot for data storage. He managed to get it all to fit into a USB thumb drive enclosure, meaning that you can program it however you want in the Arduino IDE, then plug it into any USB port and let it run. This enables things like remote monitoring, asset tracking, and all kinds of spy-like activity.
One of the most unusual aspects of his project, though, is this line: “Everything came together very nicely and the height of parts and PCBs is exactly as I planned.” [Paul] had picked out an enclosure that was only supposed to fit a single PCB, but with some careful calculations, and picky component selection, he managed to fit everything onto two 2-layer boards that snap together with a connector and fit inside the enclosure.
We’ve followed [Paul’s] progress on this project with an earlier iteration of his GSM GPS Tracker, which used a Teensy and fit snugly into a handlebar, but this one is much more versatile.
Over on Hackaday.io, [bobricius] took this technology and designed something great. It’s a GSM cell phone with a case made out of FR4. It’s beautiful, and if you’re ever in need of a beautifully crafted burner phone, this is the one to build.
The components, libraries, and toolchains to build a cellphone from scratch have been around for a very long time. Several years ago, the MIT Media Lab prototyped a very simple cellphone on a single piece of FR4. It made calls, but not much else. It was ugly, but it worked. [Bobricius] took the idea and ran with it.
Continue reading “Building Beautiful Cell Phones Out Of FR4”
What’s the most un-intrusive GPS you’ve ever seen? How about for a bike? Redditor [Fyodel] has built a Teensy-based GPS/GSM tracker that slides into your bike’s handlebars and really is out of sight.
The tracker operates on T-Mobile’s 2G service band — which will enable the device to work until about 2020 — since AT/T is phasing out their service come January. Since each positioning message averages 60 bytes, an IoT data plan is sufficient for moderate usage, with plans to switch over to a narrow-band LTE service when it becomes more affordable. [Fyodel] admits that battery life isn’t ideal at the moment, but plans to make it more efficient by using a motion sensor to ensure it’s only on when it needs to be.
Continue reading “Barely-There GSM GPS Tracker”
Just over a year ago, Particle (formerly Spark), makers of the very popular Core and Particle Photon WiFi development kits, released the first juicy tidbits for a very interesting piece of hardware. It was the Electron, a cheap, all-in-one cellular development kit with an even more interesting data plan. Particle would offer their own cellular service, allowing their tiny board to send or receive 1 Megabyte for $3.00 a month, without any contracts.
Thousands of people found this an interesting proposition and the Electron crowdfunding campaign took off like a rocket. Now, after a year of development and manufacturing, these tiny cellular boards are finally shipping out to backers and today the Electron officially launches.
Particle was kind enough to provide Hackaday with an Electron kit for a review. The short version of this review is the Electron is a great development platform, but Particle pulled off a small revolution in cellular communications and the Internet of Things
Continue reading “Particle Electron – The Solution To Cellular Things”
[Rossum] developed a host board that makes it easy to drive a TFT screen using an inexpensive microcontroller. He’s looked around at a bunch of LCD’s that are easy to get your hands on and decided that the iPod Nano 2G screens are the right balance of performance (176×132 TFT) and low cost ($1-$5). They’re not particularly difficult to talk to, but with 22 pins they’re a bit hardware hungry.
He takes us through the signal sniffing he used to figure out the communications process. From there he harness the power of an ARM Cortex M0 processor, which he’s worked with in the past, to drive the screen. His implementation results in a driver board called the SmartLCD that takes care of the screen’s parallel protocol, power, and backlight. From there it’s just four connections and you can use a small microcontroller like the Arduino seen above with ease. See what it can do after the break.
Continue reading “SmartLCD makes video for microcontrollers easy”
It seems that the iPhone 2g and 3g are the newest phones to get Android 2.2, codenamed Froyo. The process for installing Froyo if you have a jailbroken device seems to get even easier every time, with this revision being as simple as adding a repository, downloading Froyo, and pressing go. Follow the link for a wonderful step by step guide, complete with screenshots to take out all of the guess work. Android on iPhone sure has come a long way since the first time we covered it.