Hi! I am reading Tom Igoe's book, Making Things Talk, but he doesn't really talk about how the IR Transmitting IC works. If someone can explain to me how the IC works, it would be greatly appreciated. The chapter to the book, can be read here:Making Things Talk: Practical Methods for Connecting Physical Objects - Tom Igoe - Google Books
He is directing the serial output of the arduino to the IR transmitter. That is the normal serial ones and zeros are being used to make the modulated IR signal go on and off. This is then picked up by the receiver and sent out as a logic signal on a wire to go into another serial input like an other arduino or serial port of a PC.