If you need to send some wireless data from one microcontroller to another have a look at this Cheap Microcontroller IR Data Transmission project for inspiration. It uses an IR LED, a resistor and an optional visible LED for the transmitter. The receiver is just a IR receiver with no extra components. These receivers are the same that you find in DVD players other remote controlled electronics. Rentron has some good details of what makes this simple communication method work.

Via: Make