Cd400 to nav500 upgrade.

[zzattack]

I hope to be able to use my CD500 (DVD800 really) panel with an android unit eventually. I suppose that rewiring the screen has no negative impact on lost functionality at all, but losing the armrest controls would suck bigtime, so I'm trying to avoid that. Also the CD500 panel feels a lot fancier... So let's not settle for that just yet.

CD400 control panel only has 3 pins on it Power, Ground and Network Bus.
CD500 control panel has 7 pins on it Power, Ground, Wake-up, Reset, Data High, Data Low and Data Shield.

Very informative. I've managed to dump most of the button presses coming from the CD400 unit. It does require a wakeup frame on the GMLAN bus before it starts to operate. Pretty basic stuff, I'm sure I can get this 100% reverse engineered.

The screen is also wired different
cd400 screen has 8 wires Power, Ground, Network Bus, Wake-up, Reset, Data High, Data Low & Data Shield.
Cd500 screen only has 4 Power, Ground, Dimming & Remote Enable.

Are these CD400 data/reset/wake-up lines connected to the exact same lines going to the CD500 panel? Do you know what kind of protocol is used on those data lines?

If most of this can be reverse engineered we could perhaps build an adapter that translates DVD800 commands to equivalent CD400 commands. That'll allow the CD500/DVD800 panel and armrest to work with android units.