Light-emitting Diode

BontenMaru has two ordinary LEDs, one red (on the right) and the other green (on the left). They indicate when the sensor detects infrared light reflected from an object on the corresponding side. For instance, 
when there is an object on the right, the red LED lights up. The flashes of the Light-emitting Diodes in BontenMaru are similar to gestures in humans.