Hacking a vintage Star Wars AT-AT toy to walk with Arduino
Dave Stein is a software engineer during the day and a tinkerer in his free time after work. For his first Arduino project, the Maker set out to modify an old AT-AT Walker toy (from the mid-1980s) using an Arduino Uno and an Adafruit servo shield so that it could walk and perform some of the functions as seen in the Star Wars movies.
For those unfamiliar with the films, the AT-AT (All Terrain Armored Transport) is a giant four-legged transport and combat vehicle used by the Imperial ground forces. Standing at 22.5 meters tall (73.8 feet) with blast-impervious armor plating, these massive constructs are used as much for psychological effect as they are for tactical advantage.
The AT-AT Walker toy, however, is a whole lot smaller–but just as awesome on the eyes. With his updated version, Stein is able to control the device using a wired Xbox 360 gamepad that interfaces with a computer and sends a signal to the Uno for the walker movement.
The left and right triggers move the walker forward and backward while the right stick moves the head horizontally. If you have ever played with this toy you may remember it was clumsy and difficult to move. In my project I wanted to learn about and conquer the difficulties of quadrupedal movement. The realization process for my project involved a massive amount of trial and error, research, and failures. I have to say that I failed many more times than I succeeded with configuring the servos with the Arduino. I went down many long roads to learn about prototyping with the breadboard, soldering, and redesigns of the final product. The most difficult part of the project aside from adjusting the gait of the walker for balance and movement was providing enough power to the servos without frying the microcontroller or any of the components. I was finally able to overcome these difficulties by implementing the Adafruit servo shield.