Photonic Reset Of The Raspberry Pi 2

For the past month, the Raspberry Pi 2 has only been available to the Raspi Foundation, and for about 2 weeks, select members of the media who have worn the Raspi 2 on a necklace like [Flavor Flav] wears a clock. That’s not many people with real, working hardware and when a product is released, the great unwashed masses will find some really, really weird bugs. The first one to crop up is a light-sensitive reset of the Raspberry Pi 2.

[PeterO] on the Raspberry Pi forums took a few pictures – with flash – of a running Raspberry Pi 2. It took a little bit of deduction to realize that a camera flash will either reset or turn the Raspi 2 off. Yes, this is weird, and experiments are ongoing.

A short video from [Mike Redrobe] confirms the finding and a reddit thread offers an explanation. U16, a small chip located in the power supply part of the Raspi 2, is sensitive to light. Putting enough photons will cause the Pi to shut down or restart.

There’s still some research to be done, however, I can confirm a cheap green laser pointer will reset a Raspberry Pi 2 when the beam is directed at the U16 chip. This is the chip that is responsible, and this is not an EMP issue. This is a photon/light issue with the U16 chip. The solution to this bug is to either keep it in a case, or put a tiny amount of electrical tape over the chip.

Thanks [Arko] for staying up until an ungodly hour and sending this to me.

hologram

Dead Simple Hologram Effect

We’ve all seen holograms in movies, and occasionally we see various versions of the effect in real life. The idea of having a fully three-dimensional image projected magically into space is appealing, but we haven’t quite mastered it yet. [Steven] hasn’t let that stop him, though. He’s built himself a very simple device to display a sort of hologram.

His display relies on reflections. The core of the unit is a normal flat screen LCD monitor laid on its back. The other component looks like a four-sided pyramid with the top cut off. The pyramid is made from clear plastic transparency sheets, held together with scotch tape. It’s placed on top of the LCD with the narrow end facing down.

[Steven] then used the open source Blender program to design a few 3D animations. Examples include a pterodactyl flying and an approximation of the classic Princess Leia hologram from Star Wars Episode 4. The LCD screen displays the animation from four different angles at once. The images are displayed up and onto the transparency sheet, which then get reflected to your eyes. The result is an image that looks almost as if it’s floating in space if viewed from the proper angle. If you move around the screen you can see the image from all four sides, which helps to sell the effect. Not bad for a few dollars worth of parts. Continue reading “Dead Simple Hologram Effect”

Spy Pen

Turning An Ordinary Pen Into A Covert Radio Receiver

[Ben Krasnow’s] latest project will be good for anyone who wants a complicated way to cheat on a test. He’s managed to squeeze a tiny FM radio receiver into a ballpoint pen. He also built his own bone conduction microphone to make covert listening possible. The FM radio receiver is nothing too special. It’s just an off the shelf receiver that is small enough to fit into a fatter pen. The real trick is to figure out a way to listen to the radio in a way that others won’t notice. That’s where the bone conduction microphone comes in.

A normal speaker will vibrate, changing the air pressure around us. When those changes reach our ear drums, we hear sound. A bone conduction mic takes another approach. This type of microphone must be pressed up against a bone in your skull, in this case the teeth. The speaker then vibrates against the jaw and radiates up to the cochlea in the ear. The result is a speaker that is extremely quiet unless it is pressed against your face.

Building the bone conduction mic was pretty simple. [Ben] started with a typical disk-shaped piezoelectric transducer. These devices expand and contract when an alternating current is passed through them at a high enough voltage. He cut the disk into a rectangular shape so that it would fit inside of the clicker on the ballpoint pen. He then encased it in a cylinder of epoxy.

The transducer requires a much higher voltage audio signal than the litter radio normally puts out. To remedy this problem, [Ben] wired up a small impedance matching transformer to increase the voltage. With everything in place, all [Ben] has to do to listen to the radio is chew on the end of his pen. While this technology might help a cheater pass an exam, [Ben] also notes that a less nefarious use of this technology might be to place the speaker inside of the mouthpiece of a CamelBak. This would allow a hiker to listen to music without blocking out the surrounding noise. Continue reading “Turning An Ordinary Pen Into A Covert Radio Receiver”

War Gaming For Security Cred

Maybe you are an elite hax0r. But probably not. Maybe you feel like you should know more about how systems are compromised, and we’re all about that. You can’t keep the black hats out if you have no idea how they go about breaking in in the first place. That’s why war-gaming sites sprouted up in the first place. We find this one in particular to be delightfully engaging. OverTheWire’s Wargames teach you a little about security while the uninitiated also learn about simple concepts like SSH and, well… Linux!

On-the-job training is the best way to learn, and this is pretty close to it. Instead of providing an artificial avenue of learning the creators of OverTheWire have used the real thing to illustrate poor online security. You don’t “play the game” on an artificial web interface, you do it on legitimate platforms. The very first level (appropriately named Level 0) starts by figuring out how to connect to a system using Secure Shell (aka SSH). From there you’re prompted to use Linux command line tools to figure out where to go next.

Even veteran Linux/Security users should find this offering entertaining. The early stages are both quick and simple to navigate as an experienced admin while providing a welcoming learning platform for those who aren’t quite there yet. Work your way through a few different “servers” and before long your own knowledge will be tested. This isn’t a new platform, mentions of the site in Hackaday comments go back to 2010. But if you haven’t given it a try, Wargames is well worth adding to your weekend entertainment list.

[Thanks NightPhoenix]

Unbricking A Counterfeit FTDI Chip

If you haven’t been paying attention, FTDI, makers of one of the most popular USB to UART chips out there, really screwed up last October. They released a driver to Microsoft that would brick unauthorized clones of their chip by setting the USB PID pair to zero. This renders the chip unusable by any computer. That Windows driver has been fixed by now, but there’s probably still a good number of bricked FTDI chips out there. [Tony G] figured out how to fix it, and it only requires a few lines in the console of a proper OS.

The bricking Windows driver worked by setting the USB PID on fake chips to 0000. Luckily, there are ways to reprogram these chips. [Mark Lord] released a set of tools that will reset the USB PID. This unbricks the chip, fixing whatever device it’s attached to. It’s also a great reminder to either update or roll back your Windows drivers.

Modular 555 Synth Is Controlled By MIDI

[Atdiy and Whisker] aka [The Tymkrs] have created a  MIDI controlled 8 note modular synthesizer. (YouTube link). The project was designed to highlight some of the modules they have available at their Tindie Store. Essentially, the synthesizer is 8 classic Atari Punk Console (APC) tone generators. Each APC is made up of two 555 chips, rather than the 556 used in the original design. The APCs are tuned to a Pentatonic scale, with the 8 notes covering 1.5 octaves. [Whisker] added a single potentiometer which controls all 8 of the monostable oscillators at once. Tweaking this knob gives the synth that classic Atari Punk Console sound we’ve all come to know and love.

The 8 APC outputs are routed to once side of an AND gate. The other side of the AND gate is connected to a 74hc595 shift register. A Parallax Propeller processor converts MIDI note data into a serial stream that can be daisy chained across several ‘595 shift registers. The outputs of the 8 and gates are mixed to a single combined output, which goes out to [The Tymkrs] studio amplifier.

Like many [Tymkrs] videos, this one ends with a MIDI driven jam session, outlining how the circuit would sound in a song. Click past the break to see it all in action!

Continue reading “Modular 555 Synth Is Controlled By MIDI”

Mini Autonomous Robot

Cute Tiny Robot Gets A Pair Of Hacked Eyes

One day while at our poor, poor Radio Shack, [davidhend] purchased a little 6-legged walking robot. It came with an infrared remote that allowed a user to control its movements from afar. After a few minutes of making the robot walk around [davidhend] got bored and decided it would be a great toy to hack.

His plan was to make the robot autonomous and able to avoid obstacles. To start off, the robot was taken apart enough to expose the circuit board. There he found a ST1155A bi-directional motor driver that was controlled by an on-board microcontroller. After checking out the ST1155A data sheet, [davidhend] thought he would be able to drive it with an Arduino. So, out came the soldering iron and all the unnecessary components were removed from the original circuit board.

An off the shelf PING))) sensor was mounted on the front of the robot and is responsible for detecting obstacles. That information is then sent back to the Arduino Nano which controls the motor driver to make the robot back up, turn and then start walking straight again until another obstacle is detected. [davidhend] made his Arduino Code (.zip file) available to anyone who wants to make a similar project. Check out the video after the break!

Oh, and if you plan to run down to the Shack to pick up a robot of your own you better do it like right now.

Continue reading “Cute Tiny Robot Gets A Pair Of Hacked Eyes”