iPod 5.5 and my car kit

[chileboy]

I have a Gen 5.5 iPod Video which I upgraded to 240GB.  Around the same time, I installed in my car a Parrot MKi9200: http://www.parrot.com/catalog/products/parrot-mki9200/.  I recently started spending an inordinate amount of time commuting, so I wanted a way of listening to high-quality music while doing so.

My intent all along was to use Rockbox - partly because I rip everything from my original CDs to .flac files (hence my desire for the 240GB), but also due to its superiority to the OF.

I saw here that Rockbox works with a number of car audio systems, so I was hopeful that it would work with the Parrot, but it does not.  On the Parrot screen, for several seconds it displays "opening iPod", then "error: unsupported iPod/software" or something similar.

I am using the latest build (as of today) - obviously some changes have happened since 3.6, because with that version I got no message at all from the Parrot.

I tried every combination in Settings of Car Adaptor Mode, Accessory Power Supply, USB HID, etc., with the same result.

I was looking for some direction as to what I could try to get this working.  I browsed the forums quite a bit before posting, in particular I read with interest the thread about getting the iPod to load as a USB drive, but that isn't exactly what I'm trying to do and, as someone else pointed out, I could simply plug in an external USB drive for that purpose.  But the DAC in the iPod + Rockbox is noticeably better than that in the Parrot, and, anyway, as I said I really want to use Rockbox.

I'm not a developer, but I'm not unfamiliar with mucking around with this sort of thing either, and if someone can help me get started I would greatly appreciate it.

Thanks.

[saratoga]

I'm not a developer, but I'm not unfamiliar with mucking around with this sort of thing either, and if someone can help me get started I would greatly appreciate it.

It sounds like your device uses some protocol rockbox doesn't support.  Short of reverse engineering whatever it expects and then implementing support for it, theres probably nothing you can do. 

[chileboy]

It sounds like your device uses some protocol rockbox doesn't support.  Short of reverse engineering whatever it expects and then implementing support for it, theres probably nothing you can do. 

Thanks for the response.

I guess I'm not understanding something.  Wouldn't all devices have to adhere to the same protocol?  I mean, I'd think everything would expect the data to be presented via a standard format, otherwise how could the devices talk to each other?

[torne]

There is more than one standard protocol (I think three?); Apple defined new ones with later iPod models to allow accessories/docks to do more complicated stuff.

Rockbox doesn't implement the one that your device is trying to use. None of the protocols are publicly documented, you have to pay Apple for them and agree to keep them secret.

[chileboy]

OK, that makes sense.  My iPod is an older model though, you would think it uses one of the older, compatible protocols.

Parrot releases new firmware for their unit on a fairly regular basis, maybe a future release will talk to Rockbox.

In the meantime, I guess I will use ALAC and iTunes to manage my music, and remove the database.ignore in the Apple folder.  Then I can still use Rockbox and just boot to the OF when I'm in the car.  Not a great solution, but it will work for now.

I'm disappointed!  :'(

Thanks very much to both of you for your input.

[torne]

An "older model" would be, say, the Firewire-only iPods - the iPod Video is pretty late by our standards

The website for the unit suggests it can load music from normal USB storage devices. So, this is probably another instance of a case which has come up before: because Rockbox uses the same USB device IDs as the original firmware, the head unit thinks it's an iPod and expects to use the special iPod protocol to browse the iTunes database. If the device had a different device ID it would just assume it was a normal USB flash drive and would browse the filesystem directly.

It's not particularly difficult to change the USB device ID Rockbox uses; there's a patch for it around somewhere. If you did that it would probably work fine. We don't really support this because it's kinda.. hacky. The USB-IF don't like people using USB IDs that don't belong to them.

[chileboy]

An "older model" would be, say, the Firewire-only iPods - the iPod Video is pretty late by our standards

Oh, I see! 

You're correct about it being able to load from USB devices (in fact, I have tried it).  I saw the thread about changing the USB ID, but I didn't realize it also affected the manner in which the head unit would try to talk to the iPod directly.  What you say makes sense.

I also was hesitant to try it for the reasons you mention.

Is there any chance that the serial bitrate (currently set to Auto) would affect compatibility?  I didn't tinker with that at all.

One last thing, perhaps it makes sense to update the iPod accessories Wiki to show the Parrot as (mostly) incompatible?  The charging does work.

[Chronon]

If you have the time to document your experience it would be much appreciated.

[chileboy]

If you have the time to document your experience it would be much appreciated.

Understood.

[torne]

You're correct about it being able to load from USB devices (in fact, I have tried it).  I saw the thread about changing the USB ID, but I didn't realize it also affected the manner in which the head unit would try to talk to the iPod directly.  What you say makes sense.

I also was hesitant to try it for the reasons you mention.

It's perfectly safe to try it; we don't want to do it *in the main build* because of potential compatibility issues and potentially getting "in trouble" for using someone else's USB IDs (since we can't afford to pay to have our own), but there is no actual technical risk to it; feel free to try it on your own player. Even if you screw up Rockbox's ability to connect over USB completely you can just go into the Apple disk mode; ipods are unbrickable.

Is there any chance that the serial bitrate (currently set to Auto) would affect compatibility?  I didn't tinker with that at all.

No, that's not going to work. The head unit is not connecting to the iPod as an accessory at all, it's connecting to it as a USB device which doesn't use that serial bitrate.

[chileboy]

I am guessing that the best (or only) way to proceed is to use the current source code and recompile?  I am new to this, so I am starting to read up on the development - will take me a few days to figure out what I am doing.

ipods are unbrickable.

That's good to know!

I'm sure I will have some questions as I proceed.

Thanks again.

[torne]

Yes, you will need to compile your own build. Follow the guide on the wiki and it shouldn't be too hard.

[Buckstop]

There is a custom build in this thread, but I haven't tried it yet. 

http://forums.rockbox.org/index.php?topic=24360.0

[chileboy]

There is a custom build in this thread, but I haven't tried it yet. 

http://forums.rockbox.org/index.php?topic=24360.0

Yeah, I saw that, but it is a pretty old version at this point.

I've gotten my compile environment set up, and successfully compiled my own build - used the latest SVN without modifications, to make sure I could do it, as I said, I'm pretty new to this.

But, upon reflection, I'm thinking I am barking up the wrong tree anyway.  I believe that all this would allow me to do is access the files on the iPod - effectively removing Rockbox and the iPod hardware from the mix.  So the decoding would take place within the head unit of the Parrot, which is not what I want.  In that case, I could simply copy my files to a USB drive and be done with it.

The whole point is that I want to use the DACs in the iPod, which I think are superior to those in the Parrot.

And, I am using lossless files, which the Parrot doesn't support anyway.

Torne, et. al., is that correct?

[torne]

Yes, all it will do is make it behave like any other USB storage device; the only formats supported will be the ones the head unit supports. It will work exactly as well as if you copied the files to another USB device.