I've set up an
"Qualcomm Developer Network" account where they have a robot design using their system:
"Robots powered by Snapdragon processors leverage technologies working together to make robots smarter and more efficient. The Snapdragon Micro Rover is a simple design that garners lots of power and intelligence. It’s powered by a smartphone with a Snapdragon processor, is easily printed on a 3D printer and has a forklift that allows the robot to manipulate its world."
After setting up an account, I was able to download files, one of which is a PDF detailing how to build the Micro Rover. It's mostly 3D printer stuff, but has info on I/O as well.