Florin made a giant TV-B-Gone… 48 IR LEDs and an ATmega8 that sends the signals to the LEDs. Source code and schematics included. He writes –
I arranged the LEDâ€™s in 4 rows of 12 pieces and the resistors fit quite nicely between the LEDâ€™s. I used four BD139 NPN transistors to drive the rows. It took me hours to drill and then solder this board(48 LEDâ€™s and 48 resistors mean 192 holes plus the other parts). The controller board contains an ATmega8 chosen because of itâ€™s 8k memory needed to store all the codes, an 8 MHz crystal, an LED, a tact switch and some resistors and capacitors. I designed the board so that it can also be used for other projects.