Guy:
I have previously submitted some helpful information on IR decoding to this forum. You could look at this posting ---> http://www.8052.com/forum/read.phtml?id=39057. There are several downloads I made that you can link to there. One is for a cool set of code that I made whereby you can connect an IR receiver to a PC parallel port bit and then decode IR using DOS mode/box type software in Borland C.

Another link shows how to craft a state machine that triggers on each IR receiver input and decodes according to timing information from an onboard timer.

Note that a common 8051 type IR decoder connects the IR receiver output to an XOR (74HC86) type gate and then to the external interrupt pin of the 8051. The opposite input of the XOR gate connects to another port pin. This allows the 8051 code to toggle the XOR gate from invert/non invert so that the interrupt can detect both edges of the IR signal.

Some 8051's have a TIMER 2 that has an T2 pin that can operate as a capture input on a programmable edge. With this facility you can eliminate the need for an external XOR gate!!

Hope this helps.....If more questions come back and ask.....I have decoded more IR than I care to recall.

Michael Karas