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USB audio output on a Droid?


  1. qoncept

    qoncept Member

    I'm toying with the idea of making a car dock for my Droid. The official Droid dock doesn't work with any cases and if the iPhone is any indication, no one will ever make one that does. Plus, it doesn't do everything I want.

    I want to plug my phone in with as little fuss as possible, have it charge, output audio to my car stereo through USB. Charging is absolutely necessary, and I want to avoid using the headphone jack for audio if I can because it's an extra thing I'd have to plug in rather than just sliding the phone right in the dock. Better yet if the USB audio output is a constant volume intended for control on another device.

    So.. Is it possible? If I need hack a car charger in to a usb audio cable I'm fine with that (unless I could get both in one). This thing would do it, but it looks like it has more pins than standard usb (can't really tell in that pic, but maybe someone knows?), and the Droid doesn't.

    My other options are connecting the Droid directly to the head unit via USB and mounting it as a mass storage device, but I prefer the way the Droid handles music better than the head unit, and mounting the USB is an extra step I'd probably get too lazy for. And finally, I'd considered making an app that spoofs an iPod, since my HU has iPod controls, but that's more work than it's worth when the Android music player's controls are just as good.

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  2. qoncept

    qoncept Member

  3. Berry2Droid

    Berry2Droid Well-Known Member

    Keep this updated please, I have a similar issue. I wanna be able to run pandora through my car speakers..
  4. blackcobra95

    blackcobra95 Member

  5. JoeFresco

    JoeFresco Well-Known Member

    What that guy did was still using the mass storage so he was basically just playing the contents of the microSD card via the car stereo's USB port.

    It would be sweet to connect the Droid via USB like dropping an iPod in a dock and then output the audio via USB, whether it was an mp3, Pandora, or whatever.

    I suspect, though, that to do that will be quite difficult. The dock would have to establish and ADB connection with the phone (and the phone would have to be placed in USB debugging mode), and even then, I'm not positive it would work. I think this will have to be something that Google will have to add to the ASOP project officially in order to get 3rd party dock support.
  6. shadowdude777

    shadowdude777 Well-Known Member

    Yeah, the fact is that right now, the USB port just isn't DESIGNED to output sound. Think of it this way. Imagine a radio/alarm clock with an 3.5mm line in for plugging in an MP3 player (the iHome is an example of this). That port is DESIGNED to have an MP3 player plugged into it to route the music from the MP3 player to the iHome's speakers. Physically, you can plug in headphones to that port, yes. But you won't hear the iHome's radio through it no matter what you do. I'm not sure if Google will or is even able to enable this in future updates. This is not my area of expertise.
    NiceGuysFinishLast likes this.
  7. SlaveUnit

    SlaveUnit Well-Known Member

    If you take the USB to mirco USB cable provided with the charger and plug it into a car deck with a USB input the phone will charge and be treated the same as using a thumb drive. The micrsd card mounts and then you can control the music from your deck. I tried this last week in my car. But I think that is the only way it'll work.
  8. blackcobra95

    blackcobra95 Member

    I can was basically thinking of doing what that guy did in the link and wanted to add a motorola t505 to the deal.(post 26 in the same link)
    That way, it looks clean with the dock and i can use bluetooth to stream audio to the stereo system.
    The only con would be the sound quality of audio coming from the car stereo.
  9. shadowdude777

    shadowdude777 Well-Known Member

    Yeah, you can ACCESS files from the SD card using mass storage, but you can't actually send audio data through the micro USB. Not now, at least. Who knows though.
  10. zymler

    zymler New Member

    YES - I want EXACTLY the same thing --- to play Pandora through my existing car stereo. I have a Lexus RX400h and know I have to buy an adapter in order to do this. PLEASE if anyone knows what I need to buy let me know.
  11. jsquared

    jsquared Member

    interesting after getting rid of my iphone i had a useless full speed ipod cable for my headunit which was specifically for the ipod/iphones to display video and what not oh well, anyhow for those with usb connection via headunit you should be able to play music just fine...if connected. or you can always go old school and do it via AUX but that wouldn't charge the phone...
  12. RaptrFlite

    RaptrFlite New Member

    Hi all.. new member! :)

    My Hyundai Sonata actually has an Ipod mode on it that uses a special cable attached to the USB and 3.5mm jacks together. This makes me wonder if the way it works is by controlling the Ipod with USB, but sending the audio via the AUX in. I wonder if we could hack together a controller that would intercept the Ipod USB messages from the head unit and convert them to control the droid? I would assume that Apple has it's own proprietary messaging that we would have to figure out, in addition to solving the droids USB control, that is, if Droid even allows USB control. Ideas?

    Mike
  13. I don't know if control via USB is supported but control via bluetooth is. I have a JVC KD-A805 and I am able to FF, RW and pause using the buttons on my stereo. It works for the stock media player as well as for Pandora.
  14. RaptrFlite

    RaptrFlite New Member

    Nice! My HU doesn't have BT :(
  15. ibm650

    ibm650 Member

    I have a Sony radio , I wonder if it will control the droid , so I can skip tunes.
  16. fonz0r

    fonz0r New Member

    well I feel like an idiot. i paid $350 to have a PDIM (personal device interface manager, basically a USB port) installed in my 2010 camaro, only to read this thread, have my curiosity piqued, and went and sat down and set up my cars bluetooth. Damnit. i can stream pandora through the stereo with minimal skipping...bye bye xm satellite radio once my free trial is up! and if you're just using the main music app on the droid, (the HTC droid eris) at least, you can skip using the stereos buttons rather than looking at the phone, which was the whole point of getting the PDIM! Oh well, at least i figured it out before i dumped another $300 into getting an ipod. All in all, I basically paid $350 for a car charger for my droid.

    epic fail.
  17. messenger13

    messenger13 Well-Known Member

    Naw! I'd bet you can get at least $300 of that back on FreeBay. ;)
  18. qoncept

    qoncept Member

    Well, I've done some more looking around and it looks like A2DP with Bluetooth is going to be the best way to go, and then just a regular charger.

    This thing is a BT receiver with 3.5mm output Amazon.com: BlackBerry Remote Stereo Bluetooth Gateway for BlackBerry 8100, 8110, 8120, 8130, 8300, 8310, 8320, 8330, 8800, 8820, 8830, 9000 (Black): Cell Phones & Service

    I got a couple of these things to play with [​IMG]Bluetooth to RCA, Fits ALL Car Stereo AUX IN, IPOD MP3 - eBay (item 270337523490 end time Dec-26-09 02:25:00 PST)

    I have one wired up to the receiver in my garage and it's working alright, but the sound quality sucks -- hopefully it's just the old receiver. It's been too cold to work in the truck.

    The problem with these is you'll have to have an aftermarket stereo with aux input. Or you could skip these things and get a stereo that has BT (but make sure you get one that supports A2DP or it will let you do hands free calling but not stream music). The last thing is they do make some BT->FM transmitters. If you could find a wired one (FM transmitters are usually pretty damn weak but one thats wired in to your antenna should be pretty decent).

    I think I have the garage cleaned out enough to get the Sequoia in it today so I can mess with it. We'll see.
  19. shrink57

    shrink57 Well-Known Member

    I wanted a good solution for playing audio through my car stereo and read good reviews on the Motorola t505 bluetooth speakerphone, which has a built-in FM transmitter so I can play everything through my car stereo (in a fairly high radio-traffic Fort Lauderdale area). I was sceptable but picked on up at Best Buy for around $75 and it has worked great with playing my mp3's and streaming DroidLive and various other stuff I have installed. It is also a fantastic hands free bluetooth speakerphone (the people I call don't even know I am using a speakerphone). I do have a fairly critical ear (been playing keyboards professionaly for more years then I would like to admit) and it does sound great (reduced all my MP3's to a 128 bitrate to save space on my SD card). I am sure that there is better fidelity using more complex solutions but the Motorola is portable, connects to my Droid with no problem, and more then gets the job done. And I can use the buttons on the 505 to pause, foward and replay tracks with no problems.

    Neil
  20. Optimus

    Optimus Well-Known Member

    Bluetooth is probably your best bet to get streaming audio...or use a 3.5 jack to the audio in.
  21. timlitw

    timlitw Well-Known Member

    I use my Garmin 785T for audio books and my old phone would play music with bluetooth, but the garmin will only connect phone audio to the 'droid, I contacted Garmin and the won't do anything since the phone is newer than the Garmin, they couldn't have anticipated. I've read that the 'droid support a2dp and the garmin spec says "with a2dp techonolgy" what are the chances of getting this to work from the android end?
  22. tehstup

    tehstup New Member

    Long post ahead, Cliff notes:
    Droid should be capable of analog audio in/out over the data port.
    MicroUSB port is a CEA-936-A Compliant car kit port.
    I have done some testing and have not been successful.
    There are MicroUSB to 3.5mm plugs on the market that supposedly work for the droid but i have not seen any posts saying whether or not they do work nor have i gotten ahold of one for myself.

    I signed up just for this. I have the same exact desire and did not want to settle on using bluetooth or pluging in the headphone jack. I did some research and found that the droid can do audio over usb, at least it is in the design. The micro USB plug was designed into the phone to be a OTG CEA936-A compliant plug. What that means is that it must do what we want it to.

    The microUSB plug has a 5th pin that is not standard to the regular USB plug. the 5th pin is an ID pin. The droid uses it to tell what mode its data port is being used in. Supposedly, there are 3 modes - USB, UART and Analog. A resistor from the ID pin to ground on the cable side is what tells the phone what mode the data port is in.

    In the analog mode, the D+ Pin becomes a microphone input and right speaker output and is switched by the phone (ie, the D+ pin is a microphone input when in a call and is right speaker output when not in a call). The D- pin becomes the left speaker output, regaurdless of whether you are in a call or not. The ground pin is used for the speaker and microphone negative connections.

    i opened up my "multimedia" dock (what a joke) and spliced into the cable in there. i used a prototype board so i could easily change resistor values and then hooked up the D- and Ground pins to a volt meter to see if i could get some audio out of the usb port with different resistor values.

    so far, i have had no success. i believe the key to cracking this is in the resistor value needed, so far, all i have tested is a 200kOhm and 400kOhm (actual resistances were 220k and 440k, go 10% quality resistors!)

    if anybody has found a copy of the CEA-936-A specification book, it should have the appropriate resistor values needed to get the analog mode for the droid. from there, i would need to test to see if you can charge while in Analog mode, as that would be a final criteria needed for my project to be complete.

    I found a MicroUSB to 3.5mm adapter on ebay but i havent seen any report whether or not it works on the droid. i need to make a radio shack run today anyways, so i will have to see if i can find one and report back what i find.
    NiceGuysFinishLast likes this.
  23. tehstup

    tehstup New Member

    I've done some more testing. I wasnt able to find a micro usb to 3.5, but i found a mini usb to 2.5, which is the same thing with different plugs. I wired it up according to how it should work, and wasnt able to get any sound out of the speaker i had wired to the usb. So this experiment was pretty much a bust. I am starting to wonder if maybe they coded the functionality out of it with software.
    NiceGuysFinishLast likes this.
  24. Soopernova

    Soopernova New Member

    I really hope someone is able to get this figured out. I had hopes of outputting google nav turn by turn and pandora to my car speakers. I previously had a Motorola Q which also has a micro usb port and I had purchased a usb micro to stereo mini (3.5) adapter by Motorola and it worked fine on the Q. It doesn't seem to work at all on my Motorola Droid. Seems like all the components are there but maybe Google needs to add this functionality via software...who knows.

    Soop
  25. gwlaw99

    gwlaw99 Well-Known Member

    Get an FM transmitter or bluetooth if your car has it
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