Ir Interface

Some articles on ir, interface, ir interface:

Lego Mindstorms - Robotics Invention System - RCX
... to the brick's RAM via a special infrared (IR) interface ... RCX bricks can communicate with each other through the IR interface, enabling inter-brick cooperation or competition ... In addition to the IR port, there are three sensor input ports and three motor output ports (also usable for lamps, etc.) ...