In early 2016, I designed an all-in-one flight controller with the goals of having a tightly-integrated FC with integrated PDB and OSD system. I ended up completing it right around the same time many commercial FCs began including lots of the features I was looking for. I took it as far as the prototype phase, but didn't push it any further.
I recently came across the files and decided to open-source them; it was my goal all along and it seems like a waste to do so much (FUN) reverse-engineering and new design of hardware and firmware without sharing with others who may be interested.
UPDATE: I've released the entire all-in-one design as well. You can find more info here.