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bradnic

30 pin bluetooth dongle with AVRCP 1.3 or greater for ID3 tag support?

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Hi everyone.  I posted a question on a bluetooth Intravee thread on m3cutters, but figured it was best to post here.

 

Here's my question (and I'm sure there are others):

 

Will we at some point be able to add a bluetooth streaming option to an Intravee setup that preserves all the functionality provided now?  I'm an engineer so I'll take a stab at the requirements assuming minimal impact to existing setups.

 

1) find a 30 pin bluetooth dongle that properly implements bluetooth AVRCP 1.3 or higher.  I know the newer iOS supports AVRCP 1.4, so 1.4 would be best but 1.3 is the version that added ID3 tags over bluetooth

 

2) the adapter should ideally "emulate an iPod" so that as far as passing track info to the KCA-420i is concerned it is by all intents and purposes connected to an iPod.

 

3) If there's no such animal meeting requirement (2), find a replacement for the KCA-420i that is effectively a "KCA-420i with a bluetooth connection"

 

It seems to me this would provide the perfect solution for those of us with Intravees and 1st gen minis or iBus equipped BMWs and Rovers

 

thanks much

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I've not found a Bluetooth dock connector dongle that works at all, I've tried several, let alone one that supports ID3 tags.

In theory this should be possible, all the information can be provided over Bluetooth, I just haven't found such a device - if you fancy designing one then please feel free!!

As for a replacement KCA-420i, I think that's almost a non starter to 'find' such a product. Even the KCA-420i is discontinued, AI-Net is pretty much 'end of life' for Alpine, they won't make another KCA-420i type device. There are some KCA-420i 'clones' (actually more like alternatives), but they don't work reliably or consistently in the way the KCA-420i does. The only way to do this would be to design and make one with this specifically in mind.

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sobering..  I've purchased a couple of these.. a shame really as AVRVP 1.3 was released in 2007!

https://www.bluetooth.org/docman/handlers/DownloadDoc.ashx?doc_id=66609

 

I'm going to keep investigating on my end.  we may need to just breadboard something.  can't be that hard to do anymore with the right bluetooth chip.

Can we chat offline on the details?

 

Many thanks again btw for keeping the Intravee going!  I now have 2 of them :-)

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I assume the KCA-420i is using the Apple/iPod Accessory Protocol (AAP) to talk to the iPod/iPhone? some decent info here http://stackoverflow.com/questions/1720568/whats-needed-to-use-the-apple-accessory-protocol

 

which pointed me to this fantastic post from Cornell https://courses.cit.cornell.edu/ee476/FinalProjects/s2007/awr8_asl45/awr8_asl45/index.html

they used the AAP over serial to talk to the iPod and they were able to pull track info.  I assume we just need to emulate the same thing from the bluetooth side, receiving the metadata via AVRCP and then "acting like an iPod" to the KCA-420i over serial on the 30 pin connector.

 

there's also the Apple bluetooth guidelines doc which gives you a great feel for what's implemented on the bluetooth side. quite complete actually, as opposed to the reputation Apple has for being light on bluetooth implementation https://developer.apple.com/hardwaredrivers/BluetoothDesignGuidelines.pdf

 

btw may not be obvious, but if this could be pulled off it would work with any AVRCP+A2DP capable bluetooth device, not just iPods or iPhones

Edited by bradnic

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As far as I know the KCA-420i uses AAP, given the iPods that it supports I can't see any alternative. Probably the best way forwards if you want to try and do this would be to create a breakout board from the KCA-420i iPod cable. I have a few spare if you want to cut one up, or there is an e-bay seller that usually has them in the USA http://www.ebay.co.uk/itm/Alpine-Genuine-DIN-Conversion-Cable-for-Connecting-iPOD-iPHONE-to-KCA-420i-/200905232263?pt=US_Wire_Harnesses&hash=item2ec6e28f87

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Thanks for the link Richard.  Picked one up so I can study the connections.  Of course you probably have all this documented already right? Looking for a breakout board now

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I don't have information on exactly how the KCA-420i uses the dock connector pins as such, you'll have to buzz it out.

There is info on the dock connector here http://pinouts.ru/PortableDevices/ipod_pinout.shtml

and info on the AAP here http://web.student.tuwien.ac.at/~e0026607/ipod_remote/ipod_ap_new.html

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Hi bradnic

Your idea sounds amaaaazing :-)

I hope very strongly that you will find a way to do it 😃

I would be the first to buy it, hehe...

Found this here, maybe it helps you anyhow to investigate further about manufacturer, protocols or so...

http://thewirecutter.com/reviews/the-best-bluetooth-dock-adapter/

Greets

Edited by looper

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One of the problems that will have to be overcome is the way that the KCA-420i detects the iPod, I believe, but have no proof, that this is why all the devices I've tried don't work.

The KCA-420i looks for the accessory pin on the dock connector going live, this is what the early versions of the wake up mod used to kick start an iPod from deep sleep. When it detects the accessory pin is high it sends initialisation commands to the iPod and powers up the 12V charging line. If the accessory pin does not go high, the kca-420i will not see the iPod.

So, for this to work the Bluetooth dock connector dongle will need to set the accessory pin high when the iPod is paired and maybe convert the initialisation code into corresponding Bluetooth messages to even start communication.

I'm sure it's possible, it will probably just take some time to decipher exactly what commands and responses are used and some experience of designing Bluetooth devices. It may be a pre-requisite to do the single wire mod to the KCA-420i as without it there will be no power for the Bluetooth device, without power the accessory line won't go high and the KCA-420i won't supply power - just like an iPod that's in deep sleep.

Edited by RichardP

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Hi bradnic

Your idea sounds amaaaazing :-)

I hope very strongly that you will find a way to do it

I would be the first to buy it, hehe...

Found this here, maybe it helps you anyhow to investigate further about manufacturer, protocols or so...

http://thewirecutter.com/reviews/the-best-bluetooth-dock-adapter/

Greets

 

Hey looper just realized I never replied to you. sorry about that.

 

that link is pretty typical - the 30 pin bluetooth dongles only support A2DP, not AVRCP 1.3+  So even if we power it successfully you won't see any track info.   There's no advantage from using those compared to say a Miccus aux A2DP adapter wired to your aux in.  In fact only reason they even have a 30 pin on there is so you can add A2DP to an old iPod speaker dock that only has a 30 pin connector.

Edited by bradnic

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Don't worry :-)

I found it and thought maybe it will help you anyhow. And if not.... :-)

You seem to look very serious into a way to realize your idea. I hope for you aaaand us that you will find a way!!

I defenetly would buy it, hehe

Good luck with your research and prototyping....

Greets Marco

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another DIY BT post. http://blog.avrnoob.com/2012/08/diy-car-bluetooth-a2dp.html

again no metadata, but you get the idea.

 

I can get an OVC3680 board that handles A2DP and AVRCP.  Something like this 

http://www.ebay.com/itm/Mini-Bluetooth-Audio-Module-Adapter-Supports-A2DP-AVRCP-Protocol-OVC3860-/160857831166

 

need to write firmware to handle the meta data transfer via the iPod Accessory Protocol

 

Richard have I missed anything?

Edited by bradnic

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I think you will need a CPU with two serial ports and some I/O capability to mimic the iPod accessory line and provide a buffer between the KCA-420i serial interface and the BT serial interface, it depends a bit on how programmable the CPU on that module is.

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Thanks for the continued interest.

 

I've picked up a couple of bluetooth boards and have started looking into a dev environment and some protocol stacks over the last couple of weeks - definitely going the linux route for the controller portion as there are plenty of embedded options for it.

 

Gonna take a month or two to write the code, prototype and test.  If it works as planned it will basically be 'partially emulating' an iPod/iPhone to the KCA-420i and will be wirelessly connected to your iPod/iPhone with A2DP+AVRCP 1.3+. Both the emulation part and bluetooth part are a bit involved, as is the messaging between them to make it all work seamlessly.

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Found a post where we talk about wath i looking for ^^

 

Richard, you already tried the Alpine KCE-400BT Bluetooth Adapter? In the description it says that it's a AI-Net device, so it must work normaly no?

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The KCE-400BT is NOT an Ai-Net device. The clue is in the name! If it was a KCA-400BT then it's AI-Net, KCE-400BT is not.

 

Alpine do not make a 'good' Bluetooth AI-Net device.

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Wow, no friggin' way. I got this exact same idea a couple weeks ago. A bit different circumstances: my 2010 BMW 3 series (is that a sin here?) doesn't do bluetooth audio, but does ipod control. I want bluetooth control and metadata for android.

 

I already got a plan in place, I have my micro (one I happened to have on hand :) ), got an ipod and the adapter I need for the car, and I have a logic analyzer. I plan on seeing what I need to implement on the micro for it to work. I found some of the links you mentioned, there's also this: http://web.archive.org/web/20070126080857/http://ipodlinux.org/Apple_Accessory_Protocol

which is the source for a lot of the Cornell info.

 

My goal is to have the same functionality on android over bluetooth as I would with an iphone or ipod plugged in.

Anyway, have you found a bluetooth module that has avrcp1.3 or higher? (1.4 would be needed to completely replicate the ipod browsing).

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