Nice entry!
I've always tried to do an automatic gain amplifier, in order to do some IR transmission, up to 115k, which disqualifies the ubiquitous 38kHz ones.
Some MCU have a IrDA sir mode, but it is very easy to bitbang.
what isn't so easy is to have a reciever that is immune to ambiant slowly evolving light.
I'm wondering what your take would be on it.
and yes, i know some ready-to-use ir transciever exist, but that's no fun.