2009 370Z IPOD -> A2DP Bluetooth Unit

radensb

Hi all,

Here's the deal, I I bought a 2009 370Z. It does NOT support bluetooth audio streaming, which is a bummer as I primarily use Pandora. Lets face it, the media playbak options on the 2009 are outdated. Compact flash card port...really??

Ok, so I wanted to stream bluetooth audio to the stereo. There is an AV AUX port in the arm rest compartment, as well as a 30 pin IPOD adapter.

I dont have an IPOD. Im team android all the way. So I got to thinking... How can I use this IPOD adapter?? Well, Im a DYI kind of guy, especially with electronics and programming, so his was right up my ally. I am developing an interface which would be connected to the cars IPOD adapter. This interface will make the car think there is an IPOD plugged in and play audio. The interface will communicate with the car via the 30 pin adapter and with an onboard bluetooth module that supports A2DP and AVRCP 1.3 connected to a bluetooth device playing the media.

I plan to support A2DP audio streaming, media control (play,pause,next,previous) from the stereo or steering wheel controls and metadata for AVRCP 1.3 enabled bluetooth devices(artist, track, album, elapsed time, duration).

The goal is to be able to get in my car, have my phone connect, and play Pandora (or any media app) with media control and metadata display with the car in IPOD mode. The experience would be similar to having an IPOD connected, but without the limitation of only an IPOD being used.

I have looked into some of the mainstream bluetooth/IPOD adapters, but the IPOD adapter in the 370Z actively communicates with the IPOD, and if the communication timesout, the car assumes the device has been removed and disabled the IPOD menus leaving you with the "IPOD Not Connected" message. Since none of the existing adapters can respond to Apple Accessory Protocol commands, they will never work.

Would there be any interest from others here?? Obviously, this will only work or be needed with 09 370Z's with the 30 pin IPOD adapter, but being that the system is based on Apple's Accessory Protocol, it should work with any IPOD adapter interface *theoretically of course* that needs active communication.

DEpointfive0

What's the cliff notes version?

You want to make an adapter that hacks into the iPod plugin?



Buy a $20 Bluetooth dongle from Amazon
/thread

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radensb

That's what happens when you rely on cliff notes. You miss vital information. Information such as:

Fountainhead

Hi Radensb,
I've looked into that myself but haven't found anything that really works well. Nothing you'll find on the market is apple approved. Apple doesn't even sell the 30 pin connector needed, it would have to be an illegal part 2nd sourced by China. I've tried one really good adapter that supposedly emulates the iPod on the end of the cable but in my 2009 Z with Navi something wasn't happening, it was sporadic and just wouldn't stay connected. However if I took it and connected it to a home dock BAM it worked flawlessly. I just dont' have the time to analyze what it's pinout is and what's low and whats high and what's floated, etc. So I just returned it. Sigh. So close too. It even handed off to the BT in the car when calls received. A2DP with all metadata present on the car as if iPod actually connected. I just gave in and now I use an iPod Touch 1st Gen, the earlier iPods with hard drives just booted up too slow and at times wouldn't be recognized.

radensb

I have learned that this is not a trivial task. I have looked into many mainstream solutions. No dice. 99% of the ones out there only support the media streaming with the IPOD in Simple Remote controll mode. The Z uses Advanced Control Mode, and if it doesnt get the expected feedback, it doesnt show a connected device.

I have already made good progress with this. I have be able to monitor the digital communication between the car and an actual IPOD to decode the communication. I have mapped the pinout of the IPOD adapter cable and successfully programmed a microprocessor to interface with the IPOD adapter and respond to the car making it think an IPOD was in fact connected! I got access to all the menus and everything. The car uses a polling mode. This is probably why the adapter failed to stay connected. Unless the IPOD adapter is able to respond to track information requests (which are constantly sent by the car), the car will fail to keep the connection active.

My most recent success was with hardcoded test metadata. I was able to display track time information, song name, artist, and album fields when in the IPOD mode from my development system. At this point, it's time to interface my embedded system with an audio bluetooth module so that the hardcoded values can be replaced with values actually received from the phone or other connected AVRCP media device to display. Once I can control my phone media player and get metadata by interfacing with the audio bluetooth module directly, I will be able to program my embedded system to interface with it and translate the responses into response commands that the Z IPOD adapter expects. As far as the Z is concerned, its getting responses from an IPOD.

This seems to be common. I have though of giving up, but im stubborn and like a challenge. Theoretically, my current design should work. There will be room for improvement im sure, but so far, 95% of my individual tests have been successful. Its just a matter of confirming bluetooth operation with my phone and putting them all together!

Here is a block diagram:

DEpointfive0

I meant to use into the aux in actually. But then yeah, I don't know how you could get into the steering controls.

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radensb

You cant with the AUX input. You have to have the stereo in IPOD mode and the audio gets fed into the IPOD adapter. The IPOD adapter sends the steering wheel controls (and stereo controls) to an IPOD and processes the response to update the display. My system will be waiting to decode them these commands, send the appropriate translated commands to the AVRCP enabled media player and return metadata (if available) in the form of an IPOD translated response.

Fountainhead

Hi Radensb,
We are actually Apple developers with an ATS test station, I just don't have the energy to snake the ATS dongle out to my car and connect it between the 30 pin and the iDevice to capture the traffic and analyze the pin status, etc.
What you've done so far with the extended interface is impressive, good on ya! We can't dev anything without Apple approval and thus far it's just too much work for us, we are shorthanded anyway -whine - whine, haha! At least I have work!

radensb

I have developed a prototype system with an A2DP/AVRCP Bluetooth interface that connects to the car IPOD adapter cable. Ill try to get some pics uploaded soon. I can access the IPOD menus in the car, and play songs that are being streamed from Pandora or any other music app on my Android phone. I can also control the media (play, pause, next track, previous track) from the steering wheel controls and display the artist, album, and track name in the car.

I am currently working on getting the elapsed time information to update correctly, and correct some bugs.

radensb

Its been a while since I updated this, but I have made enough progress in my free time to complete a prototype that I currently use during daily driving. I have put together some snapshots to illustrate.



The system operates as follows:

1. Power up. Fetch stored Bluetooth address of previously attached device. If there is no previously attached device, enter discovery mode and wait for a connection.
2. Once connected, open an A2DP audio and AVRCP control link to the device, then send the Play command to start the media player and receive the current song metadata (track name, artist, album, length).
3. Send the Next Track command to start a new track and capture its metadata.
4. Construct the appropriate iPod formatted metadata response commands.
5. Begin responding the the Z iPod interface connection requests via the 30 pin connection, including the metadata response commands when needed.

Once the initialization is complete, the system will unlock the iPod interface control on the screen and allow the audio to pass through to the stereo. Media control is passed to the connected BT device via the iPod interface. The iPod commands are decoded and translated into BT multimedia commands. The resulting metadata is translated back into iPod command format and sent when requested to update the onscreen display in the car. To control the remote BT player:

1. Use the stereo controls in the dash or on the touch screen to play pause, or change tracks.
2. Use the steering wheel controls to send play, pause, next, or previous track commands.

I currently use the prototype to play static and streaming audio in my car via Bluetooth. The display currently shows me:

1. Track name
2. Artist
3. Album
4. Elapsed time
5. Number of track changes

So far, I have not had any problems with it operating with the other systems. When I get a phone call, It automatically sends the pause command witch causes my phone to pause the current track and answer the phone, then resumes play once the call is hung up just as you would expect it to do with an actual iPod connected.

I am currently adding a feature that will allow the audio to be transferred via a cable from the phone headphone jack to the iPod interface instead of the BT interface if desired to overcome the limitations of 16 bit BT audio quality. Personally, I think the quality is just fine, but others may be more picky. (I consider myself to be picky!) The idea is that with this configuration, only the AVRCP control link will be established if there is an audio cable detected. That way, the user gets the direct audio feed but can still control it via the car's various interfaces via the BT.

DEpointfive0

Sweeeeeeet

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Stl370

This is awesome. I get so tired of the aux. Jealous

DEpointfive0

OP, make me one!!!
Make me one!!!

(iPhone 5 compatible please?)

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Tweek

Get these kits of yours (I can only assume there's more to come after this and the backup camera) refined into end-user installable kits, and you're bound to make some money out of it!

Mitco39

I would be interested in one for our 335XI beemer as it only has the iphone capability and no bluetooth. If your thinking of making a few I would for sure take one.

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