I've started designing a smart beacon for robots. The beacon will flash one of four signitures in IR based on the setting of a jumper. It uses a PICAXE-08 that will measure the voltage generated by the jumper setting. The jumper portion of the circuit consists of four resistors in series to make a voltage divider. So a jumper setting creates either 1.25, 2.5, 3.75, or 5 volts for the PICAXE -ADC. When the PICAXE powers up, it will measure the ADC input voltage.
Now the PICAXE can't send enough current to all the IR LEDs (IREDs). So it triggers a transistor when then provides the power for the IREDs. A chromed ball above the IREDs (which are pointed inwards and up) will fan the IR out in all directions.
After completing this design, I'll build a PCB for a IR beacon detector that robots can use to locate beacons.
A beacon placed on a robot locates the robot. But a beacon can also be placed on a destination for the robot to find.