Thanks for the responses, these have been a big help, as I see it there are 2 ways to decode the IR (after it is demodulated)

1. Generate and external interrupt on recption of each level change and then service it (time the duration etc at this point)

2. set a short duration timer and then check to see if the status has changed, calculating how long it stayed at each state for to see if it is a "1" or a "0"

I have another question though and that is that the IR demod chip that I have (the 3 legged jobber) gives a 4.8mS (200Hz)square wave even when it is not receiving anything, the Level 1 is for about 3.6ms and the Logic 0 is about 1.2mSecs

is this normal? I expected to get nothing (either a constant 1 or 0) when the device was in the inactive state. and then only the demod data when it rx'd stuff, what it means is that I have to endlessly filter out all the square waves and try and look for the data.

Thanks for any suggestions

Marshall Brown