Password Guessing Robot

I built this robot to brute force unlock a car radio. I bought the radio used, not knowing it would have an anti-theft lockout. This robot could attempt every possible passcode in about 4 hours. It successfully unlocked the radio, saving me a couple hundred dollars. Building it cost about 20% of what a brand new unlocked radio would’ve. All CAD and code in github.

Build Video

This video explains how I designed, built, and programmed the robot. It also shows it in operation.

The robot had 6 linear actuators which were controlled by relays to mash the buttons. The microcontroller sequentially went through every single combination, and punched it into the radio with the actuators. Another complication was that the radio had a 30 minute lockout timer if you guessed 5 bad passwords in a row. I got around this by adding an extra relay that was wired through where the fuse normally was in the car's fusebox for the radio. This let me power cycle the radio unit and get around that 30 minute timer.