Intro: DIY Hitechnic IR Beacon
This is my own version of the IR Beacon from Hitechnic. It outputs a square wave of 1200 hz. It uses an Attiny25v microcontroller, programmed in C with AVR Studio. It "bursts" the LEDs, much like in a TV remote, to increase range.
The LEDs do appear faint in these pictures; this is because the battery goes really quickly due to the extreme current drain (about 30 - 45 minutes of continuous use). This beacon proved to reach out about 7 feet during testing.
The schematic was made in Eagle. It says "TINY22P", it is actually a TINY25v. Also, the LEDs should be facing the other way, I messed up the polarity.