Hmmmm.... I never seem to post any updates. Most under- panel work is complete... just getting ready to start the bodywork. Hoping to be painted by this summer.
I took a little time away from the garage (thanks to covid) but was able to start work on the some of the dash/ center console components. I priced the oem Aventador components and many of them were a little too expensive. However, I've managed to get a few oem, combined with some similar Huracan and Audi parts. I am going to put together a setup that looks close, and at a fraction of the price. With a little creativity and some 3d printing I'm hoping that when I'm finished it'll look and function close to oem. Of course I still need to get it all working so I'm just starting the process of decoding each individual component so that they can all communicate.
The light switches and the drive mode buttons all run on a LIN bus. The start button and the center console accessory button panel (power windows, hazard, esc, lift etc) are all basically hard wired (separate pins per function), the MMI uses RS232, and the climate control uses LIN bus and CANbus.
The LIN bus was fun to crack without access to running vehicles. I have the Aventador drive mode switches completely decoded (buttons plus leds). The Huracan headlight switches annoyingly use the same LIN bus address as the Aventador drive mode switches, so they'll have to run on separate buses. Next up will climate control.... that should be fun.
And no... the Audi forum guys were no help for anything.
Finding the LIN bus addresses is easy enough (only 60 possible).... but it is really tough to figure out the control codes. Audi helped create the standard for the LIN bus, but they don't bother following it themselves. I literally had to start pumping random codes to the switches until something happened and I could then narrow it all down. I almost fell off my seat the first time the drive mode switches lit up.
Once I have everything decoded, I'll try to put together an info sheet with all addresses and codes if there is anyone else wanting to go this route.