Brute Forcing A GPS PIN

January 5, 2013 by 120 Comments

pin

[JJ] picked up a Garmin Nuvi 780 GPS from an auction recently. One of the more frustrating features [JJ] ran into is it’s PIN code; this GPS can’t be unlocked unless a four-digit code is entered, or it’s taken to a ‘safe location’. Not wanting to let his auction windfall go to waste, [JJ] rigged up an automated brute force cracking robot to unlock this GPS.

The robot is built around an old HP scanner and a DVD drive sled to move the GPS in the X and Y axes. A clever little device made out of an eraser tip and a servo taps out every code from 0000 to 9999 and waits a bit to see if the device unlocks. It takes around 8 seconds for [JJ]’s robot to enter a single code, so entering all 10,000 PINs will take about a day and a half.

Fortunately, the people who enter these codes don’t care too much about the security of their GPS devices. The code used to unlock [JJ]’s GPS was 0248. It only took a couple of hours for the robot to enter the right code; we’d call that time well spent.

You can check out the brute force robot in action after the break.

Continue reading “Brute Forcing A GPS PIN” →

Hackaday Links: January 5, 2013

January 5, 2013 by 29 Comments

Do not aim laser at remaining eye

laser

Over on the reddits, [CarbonGod] thought he had a slightly overpowered laser pointer. His red laser pointer had a label that said it outputs less than 5 mW. The only problem is it melted black plastic and heated a thermocouple up to 140°F. [CarbonGod] is begging, borrowing, or stealing a power meter from an engineer friend, but until then we’ve got measurements from [The_Sourgrapes]. His lasers put out 105 mW (red), 56 mW (blue), and 53 mW (green).

While <5 mW lasers are fairly safe, these lasers that are labeled as having < 5 mW of output are not. Now if we only knew where to buy these overpowered lasers…

 It’s impossible to find this video in HD

rickroll

[Zach] created a physical rickroll device. It’s an Arduino and an MP3 shield hooked up to an ultrasonic sensor. When someone walks within six feet of the device, the Arduino starts playing Never Gonna Give You Up. When that person walks away, the song is paused only to start again when something else is detected by the ultrasonic sensor. There’s a hilarious video of [Zach] triggering his physical rickroll device, or you can check it out on the build page.

Hey, you! Write some code!

react

[William] wrote in to tell us about a project called ReactOS. The goal of the project is to create a free and open source operating system that is binary comparable with Windows XP. Yes, this project has been around for a very long time, but with Microsoft dropping support for XP, the ReactOS team could really use a few devs to get a beta out soon. If you know a bunch of low-level Windows stuff but haven’t ever contributed to an open source project, check out the developer’s wiki.

I’m [Johnny Knoxville] and this is electrostatic discharge

ouch

It looks like [Mehdi] is making a few instructional videos for EEs and those tinkering around with electricity. So far he has tutorials for making proper wiring connections, what not to do with ESD, how to take capacitors for granted, and demonstrating how electricity can kill you.

Penitent man shall pass…. Penitent man shall pass…

[youtube=http://www.youtube.com/watch?v=Cj8wXlSXGk0&w=470]

If gift giving were a contest, [Bradley] would win. His sister’s favorite movie is Indiana Jones and the Last Crusade, so when he needed to wrap a gift (a coffee cup, fittingly), he went all out. All the challenges required to obtain the Holy Grail are present in this present including the breath of God (needs more circular saws), the name of God (why was the letter ‘J’ even in the movie?), and the Leap of Faith (sand included).

Coming up for his sister’s birthday, a face-melting hair dryer.

Electric Imp Makes A Cat Door Tweet Its Activities

January 4, 2013 by 11 Comments

electric-imp-tweeting-cat-door

This Tweeting cat door uses the Electric Imp to read a sensor and report back to the server. The hardware is pretty neat. The board hosts an ARM Cortex-M3 processor and gets on your home network via WiFi. The mini-USB cable simply provides the power. Programming is done over the network. Our own [Brian Benchoff] had a chance to try the Imp out earlier in the Fall.

Monitoring a cat door is as good a reason as any to undertake a project. The hardware added to the board includes a reed switch mounted on the jamb along with a magnet on the door itself. There is also a blue LED that gives a bit of user feedback. The software isn’t quite as easy but it still wasn’t that bad. As with most web-connected projects getting all the parts to talk to each other was a bit of a chore. The Imp reports back to a server on the local network which then activates a PHP script that uses Sen.se to push out a Tweet.

[Thanks Pat]

Is Entropy Slowing Down Your Android Device?

January 4, 2013 by 50 Comments

071210_1705_AndroidDev11.jpg

[Lambgx02] got tired of his Android device getting bogged down and decided to dig down to the cause of the issue. His investigation led him to believe that entropy is causing the slowdown. He believes that his workaround reduces 90% of the lag on the average Android device.

So how is it possible that entropy is causing the problem? It seems there is a bottleneck when an app requests a random number from the Linux kernel running at the lowest level of the device. Android is set up to use /dev/random for all random number requests, but [Lambgx02] says that location has a very shallow pool of numbers available. When they run out the kernel has to reload with a new seed and this is blocking the app that requested the data from continuing.

His solution was to write his own app that seeds /dev/random once every second using a number from /dev/urandom. He mentions that this might cause a security vulnerability as seeding the random data in this way is not quite as random. There may also be issues with battery life, so make sure to monitor performance if you give it a try.

[via Reddit]

Estimate Velocity Using Quadrature Encoder Data

January 4, 2013 by 11 Comments

quadrature-encoder-velocityMany motors offer a quadrature encoder that give feedback on whether, and in which direction, the motor shaft is moving. But if you’re clever about analyzing the data you can use a quadrature encoder to estimate motor velocity. [Jason Sachs] makes the case that it’s fairly easy to get this wrong. Lucky for us he has carefully laid out his process of extrapolating velocity from the two edge-trigger data sources.

The process starts with reading from the encoder. Many chips have peripherals that will interface with a rotary encoder, but hardware lacking that built-in helper can still be used by monitoring pin-change interrupts. Once connected samples are taken over time and the rest is left to the quality of your algorithm.

What can this velocity data be used for? That’s up to you. But we can think of a couple of projects. It may be useful in a spinning POV display like this FPGA-based beauty. You also find quadrature encoders in exercise equipment. Knowing the velocity will help if you’re building your own computer to replace what came with that Stairmaster.

[via Reddit]

Dedicated Pandora Player Plus AirPlay Built Around The Raspberry Pi

January 4, 2013 by 8 Comments

rpi-pandora-radio

[Shaun Gehring] wanted an Internet radio player. Although he did have some troubles along the way, the final project turned out very well. Housed inside this case which used to house a spindle of bland CDs is a Raspberry Pi that plays Pandora radio and serves as an AirPlay receiver.

The GPIO header of the RPi makes this project a lot easier. [Shaun] used Adafruit’s breakout board to solder connections for the six buttons and the character LCD screen. Plug some speakers into the audio jack and the hardware end of the deal is finished. The software side of things is very similar to the BeagleBone Pandora player we looked at in September. It uses a Linux distribution (Rasbian Weezy) and the Pianobar package.

Pianobar is very versatile. You can control it using a First-In First-Out file. Once [Shaun] figured out how to use mkfifo to set up the file, he was able to control it from a script by monitor button presses and echoing the associated command to the FIFO. The finishing touch was to add AirPlay support via the shairport package.

Van De Graaff Generator Built For A Few Dollars

January 4, 2013 by 4 Comments

2-dollar-van-de-graaff-generator

This Van de Graaf generator was built using mostly parts on hand. The only thing that was purchased for the project was the Christmas ornament shaped M&M candy tin that serves as the collecting sphere. We didn’t include the in-action shot in the banner because it’s so dark. But sure enough, this will generate the visible sparks that make the device famous.

The gist of the device is that it uses rotating belt to generate static electricity. This potential is stored in the metal collecting sphere on top until a path for discharge is provided. They’re an awful lot of fun in middle-school science class as long hair can be made to stand on end if you touch one while your body is insulated from ground. This build uses a long rubber band as the belt. The band is moved by the motor from a DVD drive tray which is housed in the PVC base. An empty prescription pill bottle bridges the gap between the base and the metal sphere.

If this one is too small for you consider moving to a 900,000 Volt version.

[via Hacked Gadgets]