As a piece of protest art, “Covert Remote Protest Transmitters” ticks all the boxes. An outdoor covert projector that displayed anti-globalization messages at a G20 summit is protest. To disguise it inside a surveillance camera body housing — sticking it to the man from inside one of his own tools — is art. And a nice hack.
However you feel about the politics of globalization (and frankly, we’re stoked to be able to get cheap tech from anywhere in the world) the open-source DIY guidebook to building the rig (PDF) makes up for it all.
They installed the camera/projector long before the summit, where it sat dormant on a wall. A cell phone inside turned on the projector’s light with each ring because they attached a relay to the cell phone’s speaker circuit. In the instructions there’s an example of using a light-dependent resistor (CdS cell) to do the same thing, relying on the phone’s backlight functionality instead. There are a lot of ways to go here.
The optics consist of a couple of lenses aligned by trial and error, then fixed in place to a balsa wood frame with hot glue. A big fat Cree LED and driver provide the photons.
The video documentation of the piece is great. It’s mostly the news media reacting to the art piece as a “security breach”. A security breach would be a gun or a bomb. This was an overhead projector displaying messages that were out of the organizers’ control. Equating security with the supression of dissent is double-plus-ungood. Touché, CRPT.
Anyway, while you’re getting prepped for your next protest, have a look at the Image Fulgurator.
The Nokia 3100 is a classic in the circles we frequent. The LCD in this phone is a very cheap and very common display, and it was one of the most popular phones since the phone from Bell, making it a very popular source of cool components.
Now everything is an Internet of Thing, and cellular data for microcontroller projects is all the rage. [Charles] thought it would be interesting to use the famous Nokia 3100 to transmit and receive data. After battling with some weird connectors, he succeeded.
The Nokia 3100 doesn’t have a USB connector, as this phone was made before the EU saved us from a menagerie of cell phone chargers. Instead, this phone has a Nokia Pop-Port, a complex connector that still has TX and RX pins running at 115,200 bit/s 8N1. By fitting a USB socket onto a prototyping board, adding a few level shifters, and connecting the pins in the right order, [Charles] was able to get his Arduino talking to an old Nokia Brick.
[Charles] isn’t quite at the level of sending SMS from his confabulation, and even following a tutorial from [Ilias Giechaskiel] didn’t work. [Charles] is looking for help here, and if you have any suggestions, your input would be appreciated.
There is a problem with using a Nokia 3100 as a cheap Arduino cellular shield: it’s only 2G, and sometime soon those cell towers will be shut down. For now, though, it works, and once those 2G towers are shut down, there are plenty of options with cheap, early Android and iOS phones.
[Christian Holz, Senaka Buthpitiya, and Marius Knaust] are researchers at Yahoo that have created a biometric solution for those unlucky folks that always forget their smartphone PIN codes. Bodyprint is an authentication system that allows a variety of body parts to act as the password. These range from ears to fists.
Bodyprint uses the phone’s touchscreen as an image scanner. In order to do so, the researchers rooted an LG Nexus 5 and modified the touchscreen module. When a user sets up Bodyprint, they hold the desired body part to the touchscreen. A series of images are taken, sorted into various intensity categories. These files are stored in a database that identifies them by body type and associates the user authentication with them. When the user wants to access their phone, they simply hold that body part on the touchscreen, and Bodyprint will do the rest. There is an interesting security option: the two person authentication process. In the example shown in the video below, two users can restrict file access on a phone. Both users must be present to unlock the files on the phone.
How does Bodyprint compare to capacitive fingerprint scanners? These scanners are available on the more expensive phone models, as they require a higher touchscreen resolution and quality sensor. Bodyprint makes do with a much lower resolution of approximately 6dpi while increasing the false rejection rate to help compensate. In a 12 participant study using the ears to authenticate, accuracy was over 99% with a false rejection rate of 1 out of 13.
Continue reading “Your Body is Your PIN with Bodyprint”
After years of futzing around with 433 MHz radios and WiFi, we’re finally seeing a few dev boards that are focused on cellular radio modules. The Konekt Dash is the latest offering that puts a small u-blox SARA cellular module on a board with a small ARM Cortex M4 microcontroller for a complete cellular solution for any project you have in mind. Yes, until we get radios that make sense for an Internet of Things, this is the best you’re going to get.
If the Konekt sounds familiar, you’re right. A few months ago, Spark introduced the Electron, a cellular dev board based on the u-blox SARA-U260 module that includes a SIM with a 1MB of data a month. Practically, it’s not much different from the Konekt, but the Dash and Dash pro offer battery management and a battery connector, two power supplies, and encryption from the board to a server. There are slight differences for about the same price, but that’s what’s great about competition.
The Konekt Dash is now a few days in to a Kickstarter campaign that includes as rewards a board and a SIM with a six months to a year’s worth of data. There are a lot of things that can’t be done with WiFi, Bluetooth, or other radio modules, and if you have something like that in mind, you won’t do better than a Konekt or Spark Electron.
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…
A few years ago, small and cheap WiFi modules burst onto the scene and with that the Spark was born. It’s a tiny dev board with a TI CC3000 WiFi module, capable of turning any device into an Internet-connected device. It’s only the very beginning of the Internet of Things, yes, but an important step in the right direction. Now, Spark is unshackling itself from WiFi networks with the Spark Electron, a dev kit that comes with a cellular radio and data plan.
If you’ve ever tried to build a high altitude balloon, a project that will be out of range of WiFi, or anything else where cellular data would be a godsend, you’ll quickly realize Verizon, AT&T, Sprint, and all the other carriers out there don’t necessarily care about your project. As far as we can tell, Spark is the first company to fix this gaping hole in what cellular can do by offering their own service – 20,000 messages for $3/month and no contracts. Officially, that’s 1MB of data spread over 20k messages that are about 50 bytes in length.
There are a few dozen companies and organizations working on the next generation of The Internet Of Things, but these require completely new silicon and spectrum allocations or base stations. Right now, there’s exactly one way of getting a Thing on the Internet without WiFi, and that’s with cellular data. We have to hand it to Spark for this one, and can’t wait to see the projects that will be possible due to a trickle of Internet everywhere.
Everyone’s favorite machinist, tinkerer, YouTube celebrity, deadpan comedian, and Canadian is back with a tale of popping a few benzos, stumbling around Mexico, and wondering why everyone else on the planet is so stupid.
The hero of our story considered the feasibility of one hundred and eighty-sixth trimester abortions as he stood outside a Mexican airport watching a stockbroker complain about the battery in his cellphone. Meanwhile, cars drove by.
Here’s how you charge a phone with a car battery and an ‘ol Dixon Ticonderoga.
To charge a battery, all you really need to do is connect the terminals to a power source with the right voltage. A cell phone battery needs about three volts, and a car battery has twelve. You need a voltage divider. You can get that with a pencil. Take out a knife, get to the carbon and clay wrapped in wood, and wire the battery up. Make a cut a quarter of the way down this rather long resistor, and there you will find something around three volts.
Does it work? Yeah. It works even better if you have some tape to hold wires onto the cell phone battery when charging. Is it smart? It is if there is no other conceivable way of charging your cell phone. Should you do it? Nah. Video below. Thanks [Morris] for the link.
Continue reading “MacGyver, Jedi Knights, Ammo Stockpiles, and Candy Crush”