Car Stereo control via dock port / Apple Accessory Protocol

[sovamind]

I did some searching on the forums but didn't find anything that has been posted recently (mostly stuff from 2012 or much older) about this topic.  I installed Rockbox on my iPod Video 5G and while it works, I can't get my car interface (GROM) to recognize the iPod. 

Is this still the expected behavior?  Still?

It seems that the AAP is pretty well documented and understood at this point, so I was expecting support would be working since it was almost working for people back in 2012.  Here is a site I found which seems to detail the protocl: https://nuxx.net/wiki/Apple_Accessory_Protocol

Is there any chance that this could be fixed / added to Rockbox?  An iPod Video modified to take SD cards gives you a platform with physical buttons, long battery life, capacity up to 256GB, and durability.  Rockbox adds FLAC support but if I can't control it from my car stereo then I'm not going to be able to use Rockbox.

[sovamind]

Also the iPod Status page says that accessory support is still in progress (http://www.rockbox.org/wiki/IpodStatus#General_tasks) but then it says a serial driver has been created and links to a tracker page that is marked as completed/accepted here: http://www.rockbox.org/tracker/task/8624

[saratoga]

It seems that the AAP is pretty well documented and understood at this point, so I was expecting support would be working since it was almost working for people back in 2012.  Here is a site I found which seems to detail the protocl: https://nuxx.net/wiki/Apple_Accessory_Protocol

That document is from the early 2000s.  Everything there was added to rockbox many years ago, but Apple regularly updates the accessory protocol, so if your stereo expects a newer version, it won't help.

Also the iPod Status page says that accessory support is still in progress (http://www.rockbox.org/wiki/IpodStatus#General_tasks) but then it says a serial driver has been created and links to a tracker page that is marked as completed/accepted here

Does your car stereo even use serial for IAP?  Many newer devices use USB only.