Develop Bugs

modif dock IPhone for HD2 or else

Hello, I would like to modify an IPhone's dock in order to plug HD2 instead.
If I post this tread, it's because I already thought about this question :
1) Power 5V
By retrieving the power from the IPhone connector it's possible to have 5V and adapt it on an micro USB cable. Next simply mount the connector in place of the older.
2) audio jack 3.5
By removing the IPhone connector, there is enouth space to mount the jack 3.5 for the audio output just near the micro USB connector. We just have to connect this jack to the analog input of the dock (most IPhone dock have an analog input)
3) remote control
This is the point I need help : When you plug your HD2's headset into the phone, you have a mini remote control on the cable for :
- move forward
- move backward
- play / stop
How to adapt the dock's commands for the HD2's commands and send them through the jack 3.5 ?
All other commands are managed by the dock :
- mute
- volume
- standby
Thanks to help me in this task and excuse me for my bad english.

I think it would be easier to get one of these docks than to make your own (Trust me, i've tried )

Thanks Badwolves, but no one of them are "audio dock" and no one has got a remote control.
It's not in the subject

If i see anything, i'll let you know

The HD2 docks are also huge and bulky-- why can't anyone make something small and sleek like the iPhone dock?
I'd rather keep the phone sitting on the desk with a cable hanging out than have such a big ugly dock taking up space on my desk.

Hi,
I am also looking for something similar. What I would like is some kind of adaptor to convert a Bose sound dock for ipod/iphone in to a micro usb. Surely someone in china has done this

Not an iPhone dock but...
http://www.htcsource.com/2010/05/desk-genie-universal-dock-review/

Any non hdmi cables out there ie. rca??

Hi everyone
Is there any cables out there that either fit directly into the phone or through the dock thar output to rca or similar, as most tv's on the road or b&bs don't have a hdmi port.
Seen a mini hdmi to rca cable, but is the port on the atrix/dock a mini hdmi or some moto hybrid port.
Any info sure would make trips on the road better than STD tv rubbish.
Thanks.

I purchased an hdmi to dvi+1 connector. maybe you can get a dvi to vga than to rca and so fourth. Just trying to help. I know its a little extra but hey.
Sent from my MB860 using XDA App

wont work without a box to convert the digital to analogue, the reson dvi-vga works on pcs is because dvi can also carry an analogue signal, but that wont help in this case

HDMI is digital, RCA is analogue. You cannot feed a digital signal into something that's analogue. You need some sort of a converter box. Too expensive of a process in my opinion.
Its easier for digital gadgets to produce HDMI signals because the signal is decoded in the device that's receiving it. Analogue signals require an output with some strength to be able to make it to the receiving end----requires more power and hardware.

eatkabab said:
HDMI is digital, RCA is analogue. You cannot feed a digital signal into something that's analogue. You need some sort of a converter box. Too expensive of a process in my opinion.
Its easier for digital gadgets to produce HDMI signals because the signal is decoded in the device that's receiving it. Analogue signals require an output with some strength to be able to make it to the receiving end----requires more power and hardware.
Click to expand...
Click to collapse
correct. you could go with a MicroHDMI to HDMI, connect an HDMI to DVI+ adapter, and a headphone jack to RCA or headphone jack to headphone jack for audio, as DVI+ does not carry audio like HDMI does.
There are small portable DAC converters. they cost about $100. i have 2 for different studio equipment, but i would never use it for something like this.

eatkabab said:
HDMI is digital, RCA is analogue. You cannot feed a digital signal into something that's analogue. You need some sort of a converter box. Too expensive of a process in my opinion.
Its easier for digital gadgets to produce HDMI signals because the signal is decoded in the device that's receiving it. Analogue signals require an output with some strength to be able to make it to the receiving end----requires more power and hardware.
Click to expand...
Click to collapse
Uh...............thanks!... : /
Sent from my MB860 using XDA App

Thanks for the replies guys, so I am guessing this item wouldnt have done the job ??
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=110712983212
What is the conector on the Atrix that outputs to hdmi ?
Thanks

I would settle for HDMI -> Fiber Optic Audio

I don't know if that is possible... cause the audio out on HDMI is only triggered most likely by video out. I have an HDMI to DVI converter, and it puts out video, but doesn't put out sound since DVI can't handle sound. The video pinout is the same. The sound plays through the phone. Which makes me think that audio only would not trigger HDMI.

Yeah, I understand what you're saying, they sell black box type of deals but would like a solution cheaper than the phone itself. Not supremely important, would just be nice.

pgunning1 said:
Thanks for the replies guys, so I am guessing this item wouldnt have done the job ??
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=110712983212
What is the conector on the Atrix that outputs to hdmi ?
Thanks
Click to expand...
Click to collapse
Would love to just use hdmi but most tv in hotels/b&B's are just scart & rca. Is the output a mini hdmi or something else on the atrix, if it is I'll buy one just to try.
ATV
Paul

[Q] Audio line-out for Galaxy Nexus

Hello all ,
Is there a way to get an audio line-out from the Galaxy Nexus, either using an adapter or a docking station? I'm not looking for a solution like the one offered by the Samsung Galaxy S2's car dock (which streams bluetooth audio from the phone to the dock, then the dock turns the bluetooth streaming to analog audio through a 3.5mm port) but rather something like an adapter for the MHL port or from the docking station.
Appreciate all the help!

The obvious solution (at least to me) is to plug into the headphone jack. You could also use either the media dock or MHL adapter in conjunction with an HDMI-to-analog adapter such as the one linked below:
http://www.amazon.com/HDMI-RCA-comp...OQPU/ref=sr_1_2?ie=UTF8&qid=1321905031&sr=8-2

vespoid said:
The obvious solution (at least to me) is to plug into the headphone jack. You could also use either the media dock or MHL adapter in conjunction with an HDMI-to-analog adapter such as the one linked below:
http://www.amazon.com/HDMI-RCA-comp...OQPU/ref=sr_1_2?ie=UTF8&qid=1321905031&sr=8-2
Click to expand...
Click to collapse
He's asking for a line out solution because it will bypass the internal headphone amp that is utilized when the 3.5mm port is used. If you're plugging the phone into speakers or a sound system that way you'll get much better sound.

If the mhl -> HDMI cable adapter carries both audio and video, you could use an hdmi breakout adapter to split the digital audio. It depends on the HDMI output capabilities of the phone and the acceptability of digital audio for your needs.
Edit: would no doubt be a cumbersome solution. It all comes down to your usage scenario for the output.
Sent from my GT-P7510 using Tapatalk

Thank you vespoid, ardabey.
What OJ in Compton said, I'm looking to bypass the internal headphone amp, not sure if there are any details on the car dock or desk dock, I hope 3rd party manufacturers come up with something, any solutions are welcome.
Ali

Never thought about this, but a contactless dock with HDMI out directly to the AMP = audio bliss. Thanks to the forum for letting me see the obvious

Bumping this thread...has anyone successfully done this? I want line out audio for my car's 3.5mm AUX input - had it with my ipod and it sounded much better than through the headphone jack, as well the convenience of not having to maintain two volumes.
Hoping the official car dock that uses the 3 pin connector and has a 3.5 out would do this, but I'm worried it will just use BT to transmit the audio to the dock like I read the Nexus One dock did.

I wish too that the NG had line level out.
I think it's a limitation of the hardware. I think Apple is the online one that really uses line level out via it's dock connector.
I hope someday Google will use some sort of line level out on their reference hardware or built support directly into a newer OS.
I remember my old Dell DJ had line level out. Soooooo much better.

There is nothing wrong with the 3.5mm output sound quality wise.
Trying to drive headphone-like impedance (lower) with a line out isn't the best idea, but driving higher impedance inputs like your car deck isn't that bad as long as you let the amps do the "work" of boosting the volume and not your phone. While not optimal, the decrease in sound quality shouldn't be very noticeable.
The main advantage of the digital audio though USB (what apple does) IMO is that it eliminates the need to have both the USB plugged in to charge and the 3.5 mm cord for audio. It also allows song data to be shared and device control from the speaker/head unit. Good setups will recognize most android devices as mass USB storage and provide the same functionality, but I'm not sure how the MTS on the GN will affect this.

I would wait and see how the audio quality is from the dock. Even if it is bluetooth, the audio quality may not be that bad.

Lithoss said:
There is nothing wrong with the 3.5mm output sound quality wise.
Trying to drive headphone-like impedance (lower) with a line out isn't the best idea, but driving higher impedance inputs like your car deck isn't that bad as long as you let the amps do the "work" of boosting the volume and not your phone. While not optimal, the decrease in sound quality shouldn't be very noticeable.
The main advantage of the digital audio though USB (what apple does) IMO is that it eliminates the need to have both the USB plugged in to charge and the 3.5 mm cord for audio. It also allows song data to be shared and device control from the speaker/head unit. Good setups will recognize most android devices as mass USB storage and provide the same functionality, but I'm not sure how the MTS on the GN will affect this.
Click to expand...
Click to collapse
The problem is, that if the head unit supports MTP then yes it can read the device like mass-storage, thats fine, but it doesn't allow you to stream media from radio apps, youtube and turn-by-turn directions from gps, this is what we are looking for...
technically it's not sending analog audio output through the USB, its just reading the stored media on the phone.
I have read that samsung phones are able to accomplish sending analog audio through the USB while charging, with the correct resistance values (adapter) or possibly with software pointing the audio in that direction (for example code build into the framework/API)
this is one major thing that Android lacks over iPhone, this problem should be addressed ASAP. I'm hoping CM9 might be able to find a solution for this.

I agree, i hope they fix this soon toi. It would make the development of accessories much easier for all android phones. Seems like a no brainer but I guess Google has other priorities...

A feature request for Android 4.0 to enable USB audio:
http://code.google.com/p/android/issues/detail?id=24614

Juvenall said:
A feature request for Android 4.0 to enable USB audio:
http://code.google.com/p/android/issues/detail?id=24614
Click to expand...
Click to collapse
Just starred this, if the hardware is able to do that I find it completely stupid that they do not allow it.
Smartphones audio amps are not exactly famous for being top-quality so having this possibility would be great.

Thanks. The lack of this feature is ridiculous/mind-boggling/suprising.

Well, if you were waiting for the card dock to solve your problems... it doesn't. Plugging into the dock's "line out" gets you amp driven sound. I really do not understand why this is such an issue for Android. When I plug somoething into my 3 year old Nokia smartphone a window pops up for me to choose headphones, headset or line out. Why can't ICS offer the option and if in the car dock, default to line out? A USB solution is not going to help if you are using the car dock.

Juvenall said:
A feature request for Android 4.0 to enable USB audio:
http://code.google.com/p/android/issues/detail?id=24614
Click to expand...
Click to collapse
Yes, most def. I want to use several USB dacs on hand. Off for some op amp rollin'.
Edit: The pogo pin dock has a 3.5mm analog/digital output, FYI

Oops

flacoff said:
Edit: The pogo pin dock has a 3.5mm analog/digital output, FYI
Click to expand...
Click to collapse
Which if I understand correctly uses Bluetooth to transmit compressed audio from the phone to the dock, then delivers it through the 3.5mm jack. Why not just have a digital signal go through the USB port!?

ali87 said:
Which if I understand correctly uses Bluetooth to transmit compressed audio from the phone to the dock, then delivers it through the 3.5mm jack. Why not just have a digital signal go through the USB port!?
Click to expand...
Click to collapse
actually the pogo pin transfers the digitial audio and the dock decodes it into analog to the 3.5mm output

Need this cable: Micro USB to 3.5mm & USB splitter

Dear awesome community,
For the past month or more I've been trying to find a place where they sell Mirco-USB to 3.5mm/USB cables, but I have come to no success whatsoever!
Is such cable impossible to make? Or am I just looking in the wrong places.
Check out the attached picture that I've created to show what I need and mean.
It looks simple, right? Now, I would love to get one of these at any price.
Help me!

Dear awesome user.
The practical application of this would be ?

blobotorian said:
Dear awesome user.
The practical application of this would be ?
Click to expand...
Click to collapse
Well, instead of having two wires coming out of my Note (Top and bottom) while I'm driving, a cable like this well have only one wire coming out from under the phone, cutting on clutter and annoying wires.

must be out there
heres something similar but is mini usb which is no good.
http://www.ebay.co.uk/itm/2-1-MINI-USB-3-5MM-JACK-MINI-USB-HTC-ADAPTER-/260655181793

indie said:
must be out there
heres something similar but is mini usb which is no good.
http://www.ebay.co.uk/itm/2-1-MINI-USB-3-5MM-JACK-MINI-USB-HTC-ADAPTER-/260655181793
Click to expand...
Click to collapse
Shouldn't a micro-usb to mini-usb converter work? IF it supports audio over usb that is
Sent from my Optimus 2X using xda premium

hobs0n said:
Shouldn't a micro-usb to mini-usb converter work? IF it supports audio over usb that is
Click to expand...
Click to collapse
That's totally proprietary. The phone that that is made for probably doesn't even have a 3.5mm jack.

biggy83 said:
Well, instead of having two wires coming out of my Note (Top and bottom) while I'm driving, a cable like this well have only one wire coming out from under the phone, cutting on clutter and annoying wires.
Click to expand...
Click to collapse
Well.. sorry to be a troll. However, you started this thread conveniently assuming that Headphone output through MicroUSB port of Note will work? Its not an HTC phone which has headset support.
May I know the reason for your ASSUMPTION that it would work even if you get the cable?

Your best bet for a single plug into your phone would probably be to use an MHL>HDMI adapter, and then get another adapter to convert from HDMI audio to 3.5mm.
That would be rather clunky though. HDMI > Anything (that isn't DVI) converters are going to run you at least about $40 for a start, and they aren't small either (probably not much smaller than the phone itself .) And they are externally-powered, so you'd need to provide power to both the MHL dongle and the HDMI converter, so it'd be super untidy.
You could do it though.
But you're probably better off using Bluetooth.

Prankey said:
Well.. sorry to be a troll. However, you started this thread conveniently assuming that Headphone output through MicroUSB port of Note will work? Its not an HTC phone which has headset support.
May I know the reason for your ASSUMPTION that it would work even if you get the cable?
Click to expand...
Click to collapse
My assumption comes from the fact that there is a "docking" option in the system settings of the Galaxy Note, meaning that there is support for docking stations and probably audio output for them.
I'm not saying that the Note is the only and first phone to have it, I'm just wondering if there are such cables out there and if such thing possible to be made through Micro USB.
I had an iPhone almost 2 years ago and such cable was available easily and it did really help in my car setup, and since the Note has the same slot setup of my old iPhone I would really like to know if a cable like that is somewhere out there.

Prankey said:
Well.. sorry to be a troll. However, you started this thread conveniently assuming that Headphone output through MicroUSB port of Note will work? Its not an HTC phone which has headset support.
May I know the reason for your ASSUMPTION that it would work even if you get the cable?
Click to expand...
Click to collapse
Well, looking at this car docking station...
(Link not allowed. Search for "Genuine Samsung Galaxy Note Vehicle Dock - ECS-K1E1BEGSTD" on MobileFun)
...it clearly shows a "speaker line out" socket in one of the photos, with only one connector (i.e. the micro USB connector) attaching to the phone.
So it is most certainly possible.

Hmmm, the both the official desktop dock and car dock have a 3.5mm audio out. It seems unlikely that there would be a USB DAC in the docks themselves, which suggests that analogue audio is being piped out the microUSB port on the phone itself.
Of course, the OP could just buy the official car dock to get nice tidy cabling...

If i understood the purpose of this cable, it would be:
For example:
My car supports audio input so the purpose of a cable like this would be to stream music to my car audio system and recharge de phone like a all-in-one right?

gordonshowers said:
Well, looking at this car docking station...
(Link not allowed. Search for "Genuine Samsung Galaxy Note Vehicle Dock - ECS-K1E1BEGSTD" on MobileFun)
...it clearly shows a "speaker line out" socket in one of the photos, with only one connector (i.e. the micro USB connector) attaching to the phone.
So it is most certainly possible.
Click to expand...
Click to collapse
Exactly! I found out about this dock yesterday and I'm still wondering why isn't anything like of what I suggested earlier available? How come now one asked about this before!

zylor said:
If i understood the purpose of this cable, it would be:
For example:
My car supports audio input so the purpose of a cable like this would be to stream music to my car audio system and recharge de phone like a all-in-one right?
Click to expand...
Click to collapse
That is exactly what I want!

Very Interested in this as well. OEM dock wont work with a case. So this would be a great alternative paired with a car cradle such as this.

biggy83 said:
Dear awesome community,
For the past month or more I've been trying to find a place where they sell Mirco-USB to 3.5mm/USB cables, but I have come to no success whatsoever!
Is such cable impossible to make? Or am I just looking in the wrong places.
Check out the attached picture that I've created to show what I need and mean.
It looks simple, right? Now, I would love to get one of these at any price.
Help me!
Click to expand...
Click to collapse
This:
+
This:
$7 + Shipping

I too really want one of these.
It is obviously possible as the destop & car dock do this.
The only way is, for someone with some electronics knowledge to pull one of these apart to see how its done. It would be interesting to see if it is straight audio out, or if there is a "Digital to Analogue Converter in there"

http://www.ebay.com/itm/Samsung-ET-...&otn=3&po=LVI&ps=63&clkid=5051243939125627988
This might do the trick in the unlikely case that Note's microusb outputs audio. Tough I'm really interested in knowing for sure if the Galaxy Note microusb pumps line level audio.
Judging by the price of the desktop dock i wouldn't bet my money on the idea that it has not a dac. I

Use Bluetooth.

maybe at usbfever.com or dealextreme.com
---------- Post added at 07:41 AM ---------- Previous post was at 07:39 AM ----------
http://www.cablejive.com/ maybe

Audio output AND charger using the micro-usb port

Hi,
I want to have only 1 plug to insert in the Samsung Galaxy S2 to have:
- Audio output
- AND power charging
This is possible by using the micro-usb port of the Samsung Galaxy S2.
This is how the official Samsung docks works: http://www.samsung.com/us/mobile/cell-phones-accessories/ECR-D1D3BEGSTA )
But I am not looking for a dock, I just want a cable ! (it is much more convenient than a dock)
This cable would be like this:
Code:
|---------> Audio output jack
Micro-USB <---|
|---------> Standard USB (type A)
Where can I buy such a cable ?
Regards, Chris

I guess you have to make one yourself. It shouldn't be too difficult.
You just have to solder a 365K resistor to the ID pin of the micro usb plug. Then solder The data pins and the ground pin to a 3.5mm socket. At last you need to solder the +5V pin and the ground pin to the USB plug.
I have to say I like the Idea of such a cable, I think i'm goibg to make one.

I got the official vehicle dock and the sound coming from the line out isn't so good compared to the headphone jack. I'm wondering if the components within the dock is to blame or the phone itself (kernel?)
If the OP does find a cable that does the job I'd be keen to know how it turns out.

wurzelsepp3 said:
I guess you have to make one yourself. It shouldn't be too difficult.
You just have to solder a 365K resistor to the ID pin of the micro usb plug. Then solder The data pins and the ground pin to a 3.5mm socket. At last you need to solder the +5V pin and the ground pin to the USB plug.
I have to say I like the Idea of such a cable, I think i'm goibg to make one.
Click to expand...
Click to collapse
I am very surprised, no one is manufacturing such a cable. I am sure there is a big business for it.
I have never soldered anything. It is possible to make 2, one for me as well ? I would be very happy! I am based in Paris.
bricked_tab said:
I got the official vehicle dock and the sound coming from the line out isn't so good compared to the headphone jack. I'm wondering if the components within the dock is to blame or the phone itself (kernel?)
If the OP does find a cable that does the job I'd be keen to know how it turns out.
Click to expand...
Click to collapse
The quality should be good, as Samsung is selling a docking stations to output the sound on a hifi system. Bad sound quality is not noticeable on basic headphones, but on a hifi system that would be catastrophic (so Samsung would not sell docking stations).

bricked_tab said:
I got the official vehicle dock and the sound coming from the line out isn't so good compared to the headphone jack. I'm wondering if the components within the dock is to blame or the phone itself (kernel?)
If the OP does find a cable that does the job I'd be keen to know how it turns out.
Click to expand...
Click to collapse
You need an amp to improve the sound from the line out since it is unfiltered and not treated through the phone's yamaha pre amp.

chiefroastbeef said:
You need an amp to improve the sound from the line out since it is unfiltered and not treated through the phone's yamaha pre amp.
Click to expand...
Click to collapse
Thanks a million chiefroastbeef! Luckily I have a cmoy amp and man did it make a difference. I'm keeping this post short because I don't want to hijack the thread any further so thanks again chiefroastbeef

bricked_tab said:
Thanks a million chiefroastbeef! Luckily I have a cmoy amp and man did it make a difference. I'm keeping this post short because I don't want to hijack the thread any further so thanks again chiefroastbeef
Click to expand...
Click to collapse
Ahh, the cmoy, very cool headphone amp. I have a DIY AMB mini3 with an Alien dac connected to my computer. Now with the info from this thread, I really want line out! Though I must admit, 2.3.5 with poweramp sounds really good.

Ok the Cable is finished, when plugging the cable in the phone automatically enters dock mode and outputs audio via the micro-USB port.
Quality is OK I guess (I will compare it to the quality of the 3.5mm headphone-jack output), but keep in mind that I'm not an audiophile .
The build quality of my cable is not great, but it was more or less just a proof of concept.

wurzelsepp3 said:
Ok the Cable is finished, when plugging the cable in the phone automatically enters dock mode and outputs audio via the micro-USB port.
Quality is OK I guess (I will compare it to the quality of the 3.5mm headphone-jack output), but keep in mind that I'm not an audiophile .
The build quality of my cable is not great, but it was more or less just a proof of concept.
Click to expand...
Click to collapse
That looks very promising, thank you for sharing!
Keep in mind, line out is unfilter, unamp audio output, so the sound will sound a bit bland. One must plug an amp into it to "color" the sound.

Good on you, wurzelsepp3. As for the audio quality between the headphone jack and line out I'm pretty sure you'll notice it but it shouldn't be a problem if you just want the functionality.
I just tested the cmoy amp in my car and it sounds good now.

wurzelsepp3 said:
Ok the Cable is finished, when plugging the cable in the phone automatically enters dock mode and outputs audio via the micro-USB port.
Quality is OK I guess (I will compare it to the quality of the 3.5mm headphone-jack output), but keep in mind that I'm not an audiophile .
The build quality of my cable is not great, but it was more or less just a proof of concept.
Click to expand...
Click to collapse
Excellent !!
I need such a cable too !
Can you post how you built it ? I am not good at electronics.
I guess you have taken:
- a USB (type A) cable
- a jack cable
- and a micro-USB
and then cut all of them to just keep the plugs. But then how did you joined the different cables together and how did you installed the resistor ?

wurzelsepp3 said:
Ok the Cable is finished, when plugging the cable in the phone automatically enters dock mode and outputs audio via the micro-USB port.
Quality is OK I guess (I will compare it to the quality of the 3.5mm headphone-jack output), but keep in mind that I'm not an audiophile .
The build quality of my cable is not great, but it was more or less just a proof of concept.
Click to expand...
Click to collapse
Hai wurzelsepp3,
I like your cable could you please post more photos of cable end pins and give more details of connection diagram, it will help us to make one.
Thanks n advance

wurzelsepp3, can you send the description of you cable.
Regards

I made a little paint drawing to show the wiring I hope it helps.
I will try to answer any questions .

Thanks for Image
Hi wurzelsepp3,
Thanks for your Sketch, please confirm whether it is same for car dock mode and desktop mode only by change of resister value and please confirm following my comments
1) Is it possible to charge the phone as per your sketch through PC usb port and via car charger out.
2) Is it possible to hear songs from stereo socket out through stereo headphone.
3) Is it possible to connected car audio system/external sound system because i saw another link like this
http://forum.xda-developers.com/archive/index.php/t-1249775.html
http://imghostr.me/images/5p7yC.jpg
http://imghostr.me/images/gs7Sp.jpg
http://imghostr.me/images/geac.jpg
Thanks n regards
Safeed
wurzelsepp3 said:
I made a little paint drawing to show the wiring I hope it helps.
I will try to answer any questions .
Click to expand...
Click to collapse

safeed said:
Hi wurzelsepp3,
Thanks for your Sketch, please confirm whether it is same for car dock mode and desktop mode only by change of resister value and please confirm following my comments
1) Is it possible to charge the phone as per your sketch through PC usb port and via car charger out.
2) Is it possible to hear songs from stereo socket out through stereo headphone.
3) Is it possible to connected car audio system/external sound system because i saw another link like this
Click to expand...
Click to collapse
Yes the only difference between car and desk-dock mode is the resistor value.
1) Yes the USB-plugs only purpose in this setup is to supply power, so any charger will do the job
2) Yes, but you have to keep in mind that the sund coming out of the micro usb port isn't amplified, so sound quality and volume are rather low, so you might wanna use an external headphone amplifier
3) Yes, as car and external audio systems have a amplifier it should work quite well.

Would something like this work?
http://www.ebay.com/itm/Samsung-ET-AUM3SBEBXAR-micro-USB-3-5mm-Male-Line-In-/250956064170?_trksid=p3286.m7&_trkparms=algo%3DLVI%26itu%3DUCI%26otn%3D3%26po%3DLVI%26ps%3D63%26clkid%3D5051243939125627988

i will have 3 cables to sell on here for $25 by the end of the week. Let me know if people want them

Docking Station
Finally I made my own style 3 in 1 Dock station, includes Car dock, Home dock and auxiliary audio out with the help of selector switch. Conversion of car dock to home dock by sliding the selector switch,also possible to charge the phone from home or Car dock mode. Auxiliary audio sound is nice to hear and All items compacted in small case.
Thanks for all, to give me such idea and sketches.

Are all the micro-USB to 3.5mm jack you find on eBay the same? Do they have the same pinout/resistance required for use on the SGS2?