That's the NEC protocol. It's one of the oldest and is used by more manufacturers than any other. It's very reliable as it has error detection built in (although some implementations do not use that). I have shown how to send/receive it (as RF) in this thread http://www.picbasic.co.uk/forum/showthread.php?t=6261. You just have to account for the fact that the IR receiver is active low while the RF receiver is active high. There is a link within that post to a NEC datasheet that explains it completely. I've decoded the third image and attached it. Hitachi is using error detection - the first two bytes sum to FF as do the third and fourth bytes.
Bookmarks