e-puck ground sensors
The e-puck ground sensors extension contains three infrared (IR) proximity sensors pointing directly to the ground in front of the e-puck robot. These sensors are mounted on a small board which is placed in the slot near the front of the e-puck's plastic base. The board also includes a micro-controller that continually samples the IR sensors. The value of the sensors can then be read by the e-puck through the I2C serial interface.
The e-puck ground sensors can be used for many different applications, such as following a black line on a white surface, surface-detection below the robot, or fall-detection. The ground sensor user manual is available here. More information is available here.