IR Beacon click is like a lighthouse for infrared receivers. It has nine infrared diodes arranged in a semi-circle. Each one is encased in a transparent plastic package with a tiny lens that casts IR waves at a wide angle (±25 degrees angle of half intensity for each individual diode).
When you pair it with a receiver, like the one on IR click, you can have two robots communicate. The mainboard MCU drives the nine diodes through a MOD pin, which provides the carrier signal (at a frequency matched to the receiver, in case of IR click that’s 38 kHz). Data is encoded within the carrier wave either as a PWM or a UART signal.
Robot battle venues are not big. IR Beacon click has a range of about half a meter. If you need more, you can stack few clicks onto a single socket.