I spent the entire day today working on this beast:
A little while ago I picked up a nice Garmi Nuvi 780 at a freight recovery auction. Its protected by a pin code, that cannot be reset unless either the correct code is entered, or it is taken to its "safe location".
I have seen a couple of other people do brute force cracks on these, and decided to give it a shot.
Entirely built from junk I had laying around, starting with an HP scanner. I don't have the hardware laying around to drive the stock stepper motor, so i decided to use servos instead. On top of the scanner's sled is a gutted DVD drive. 2 servo's for X and Y, and a 3rd servo for pushing a pencil eraser stylus onto the screen. I didn't have servo horns, so I used clothes pins instead. Most everything is hot glued together. Its all run by an Arduino Nano.
The code counts from 0000 to 9999, waiting for the appropriate delay between each attempt. At this rate, it will take about 36-40hrs to go through each pin.
Here it is in action:
That's about it. I'll report back when I find the pin!
That was quick, it was 0248. Only took a couple of hours!
The robot does not currently have any check procedure to see if the device unlocked and will continue to pound the screen even after it unlocks. I figured this may not be a problem, and let it run. I had plans to add a camera to monitor its progress if this does not work or re-locks the device.
Coincidentally, I went downstairs to check on its progress about 2 hrs in, and I witnessed the unlock with my own eyes!
Here's the code (not cleaned up): http://www.dashfest.com/garmincrack.txt