I built a virtual wall from these plans to see if I could program the iRobot Create to follow a beacon. The virtual wall puts out an infrared signal just like a TV remote control that the iRobot Create can see. I wrote a program in Python on my mac that controls the robot. When the robot sees the virtual wall it stops, when the virtual wall moves the robot starts spinning again to look for the virtual wall.
Next step...add an ultrasonic sensor and change the program so that the robot can follow the virtual wall in two dimensions instead of just spinning around.
