AVR-Chat

For transmitting data from an AVR, the data needs to amplified.  The 
current coming out a single port pin is not enough to drive an 
infraRed LED.   To boost the signal, I've had success with a ULN2003a 
chip.  Do a Google search for a chip's datasheet in PDF for more info.

 The infra red signal is switched on and off about 40000 times a 
second.  Then this 40K pulse train is switched on and off in a code 
pattern.  Every big company has their own code, which is why a Sony 
remote doesn't work with a Panasonic.  They use different codes, but 
the infraRed is switched 40K by all.  The 40K switching prevents the 
IR receiver from acting on any background infrared light in the room. 

 To detect the IR LED signal, try using a Panasonic PNA4601M.  This 3-
pin chip will capture and amplify the infraRed signal and remove the 
40K pulsing.  It will put out the IR code at +5V and 0 levels.  This 
signal can go directly into the port pin on an AVR.