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Pololu IR Beacon

For Cat & Mouse Chase


Temporary out of Stock
BR800001 28.21

The IR beacons (infrared beacons) are small devices that allow pairs of autonomous robots to detect each other. You can use the beacons to build pairs of robots that interact or chase one another, or to make a robot that can identify and return to a home base. For example, you could build a "cat robot" and "mouse robot" that each have an IR beacon, where the cat chases the mouse and the mouse runs away from the cat.

The beacons are ideal for autonomous robot contests in which robots compete in pairs. The IR beacon is a kit; before using it, you need to assemble the beacon by soldering its components onto its circuit board. To use the kit in robotics projects, you need to connect it to your own robot controller. Please note that pricing is for one IR beacon.

Device specifications

PCB size: 1.3" x 1.3"
IR modulation frequency: 56 kHz
Output Refresh rate 20 Hz
Detection range: 6 inches to 20 feet
Supply voltage: 5.1-10 V
Data voltage: 0 and 5 V
Number of IR detectors: 4
Components in kit: 25

How the IR Beacons Work

The beacons work by transmitting and detecting infrared light, much like a television remote control. Each beacon has four IR emitters and four IR detectors. The beacons alternate between transmitting and receiving so that they never get confused by reflections of their own transmissions.

The transmit and detect cycle is carried out more than one thousand times per second, and a small microcontroller monitors all four detectors to decide the direction to the other beacon. The beacons have four red LEDs that indicate the direction to the other beacon; if you take two beacons and rotate them, the LEDs will always keep lighting up in the direction of the other beacon.

Interfacing to the beacon is simple it has four digital outputs that indicate which of its four sides detects the other beacon the strongest. You can establish the direction to another beacon to within a few degrees by rotating the beacon back and forth and noting the point where the output switches from one side to another. An enable input lets you select between active mode and a low-power mode.

Please take a look at the user's guide for assembly instructions and further discussion of how the beacon works.



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Copyright 2003 British Robotics
Last modified: March 16, 2008