iPod dock adapter for the Motorola Droid/Milestone
—> The PDF version of this article can be found here.
Manufacturers of electronic devices don’t seem to be able to get a global standard on docking connectors, resulting in that you usually end up buying a new dock for every electronic device you acquire. In the past I bought multiple iPod docks (also see my other article about bypassing the Apple video out protection on older docks here), but I own more devices than just the ones from Apple. My current mobile phone is a Motorola Milestone (or Droid if you are from the US), which of course does not fit on an iPod dock. Not willing to buy new docks I decided to build an adapter to enable me to use my iPod docks with my mobile phone. This article will describe step-by-step how I have built this dock adapter.
Because I am from Europe (the Netherlands to be precise) my Motorola device is named a Milestone, but the whole article of course is just as applicable to the Motorola Droid. For the ease of use I will just refer to the ‘Motorola Milestone’ in this article from now on.
Since all the information in this document is gathered from the internet or analyzed by myself it could be that there are some errors in this document, I am sorry if that is the case. Any opinion expressed in this document is solely my own.
Goals
The goal of this project is to create a dock adapter which enables the Motorola Milestone to charge, output music and switch to docking (multimedia) mode. The Motorola Milestone charges through the micro USB connector on its side. To enable charging through our dock adapter we will need to equip it with a micro USB connector.
Since the Motorola Milestone does not provide audio output through the micro USB connector, we will have to use the headphone connector on the top of the device to enable audio out.
To enable automatic switching to docking mode on the Motorola Milestone the device is equipped with a magnetic sensor. When a magnet is placed against a certain location on the device it will recognize the dock type (Media or Car) by the polarization of the magnet. With some testing I found the best location for the magnet is at the back of the device above the micro USB connector and a bit to the right. This location is shown on the picture below which shows the back of the Motorola Milestone.
Using a magnet in our dock adapter will enable us to use the multimedia docking mode.
So, our dock connector will need to have a micro USB and audio connector as well as a magnet in it. The last part to enable us to connect it to the iPod dock will of course be a connector which fits the iPod dock itself. The schematic design for the dock adapter is shown in the next image.
Parts
This chapter will list all the parts that are needed to create the dock adapter. The specific parts used in this document might not be the most obvious, but they were cheap and available at the time of executing this project.
iPod dock connector
Since good dock connectors seem to be quite expensive and hard to find, I decided to buy a cheap Dock extender cable and harvest the connector from that. The Dock extender cable has been bought from DealExtreme for just $3.14:
Dock Extender Male/Female Cable for All iPod/iPhone 2G/3G
http://www.dealextreme.com/details.dx/sku.21892
The dock connector from this cable has almost all the pins available to make use of and provides nice solder pads to connect wires to. Since this is not always the case it is good to keep this in mind when looking for a suitable dock connector.
3,5 mm stereo audio plug
The audio cable I used in this project was one I had lying around. It suited this project fine since it had an angled jack connector, which I preferred. An alternative cable could be bought from DealExtreme for just $1.80:
3.5mm Male to 3.5mm + 2.5mm Audio Male Audio Cable
http://www.dealextreme.com/details.dx/sku.39763
Of course any 3,5 mm stereo audio plug will be fine.
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Micro USB connector
The Micro USB connector I used in this project has been harvested from a headphone adapter for another Motorola device. I bought this connector with the hope it would enable audio out from the micro USB port of the Motorola Milestone (which it of course did not). This adapter has been bought from DealExtreme for just $2.27:
3.5mm Stereo Audio Headphone Adapter For Motorola V8/V9
http://www.dealextreme.com/details.dx/sku.30099
Of course any micro USB connector will be fine.
Magnets
To enable the docking mode on the Motorola Milestone we will need some magnets, the following magnets from DealExtreme will suit our needs just fine for only $2.09:
Super-Strong Rare-Earth RE Magnets (10-Pack 9 mm)
http://www.dealextreme.com/details.dx/sku.3461
I ended up using four out of the ten magnets.
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Polymorph
To create the encasing of the dock adapter we will use Polymorph, which is a polymer that can easily be moulded when heated at moderate temperatures. Polymorph is great stuff for prototyping and can be remoulded time after time. I bought my Polymorph from eBay, but it can be found at various places online. Some more info can be found on the website of the company I bought it from:
http://www.c-d-c-shop.com/polymorph.htm
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Pin outs
Before we can start to build the dock we will need the pinouts of the various components. This chapter will show the pinouts for all the components used.
3,5mm stereo audio plug pinout
The following image shows the pinout of the 3,5mm stereo audio plug
The pinout for the 3,5mm stereo audio plug can also be found online at:
- http://pinouts.ru/Home/Tele35s_pinout.shtml
Micro USB pinout
The following image shows the pinout of the micro USB plug from the Motorola Milestone side, not the cable side. The cable side is the same pinout in opposite direction.
The pinout for the micro USB connector can also be found online at:
- http://pinoutsguide.com/CellularPhones-Nokia/micro_usb_connector_pinout.shtml
Dock connector pinout
The following image shows the pinout of the Apple iPod dock connector on the board we will be using to create our adapter.
The pinout for the iPod dock connector can also be found online at:
- http://pinouts.ru/PortableDevices/ipod_pinout.shtml
Wiring
Now that we have all the pinouts for the components we can now see how we should wire the components together. The table below shows which pins should be connected together.
| Component | Connector | Wire colour | Connected to |
| 3,5 mm stereo | GND (audio) | Metal | Dock 2 |
| Audio right | Red | Dock 3 | |
| Audio left | White | Dock 4 | |
| Micro USB | GND (USB) | Copper | Dock 16 |
| Vcc | Red | Dock 23 | |
| Data - | Green – Blue | Data + |
The colours mentioned in the table refer to the wire colours of the components named in this article, when using other components these wire colours will probably be different.
To enable the Motorola Milestone to accept the power on the USB port, the USB Data- and Data+ connections should be linked to each other. Without these points connected the device will not charge.
The following image shows the wiring inside our dock adapter.
Building the adapter
Having the different components, the design and the wiring schematics, it is now time to actually build the adapter. After soldering the components together I shortened the original dock encasing a bit because it was larger than needed. To hold everything together I filled the dock encasing with hot glue, resulting in the prototype shown below.
Polymorph encasing
The prototype showed above already works as a dock adapter however it does not hold the Motorola Milestone in its place. To build an encasing for the dock adapter that holds the Motorola Milestone in its place we will be using Polymorph.
Polymorph consists of small plastic pellets which can be melted in hot water. My general approach is to melt the pellets in hot water, press them together and making small sheets of plastic of it. These plastic sheets can be cut with scissors to preferred sizes. I personally like to use a hot air gun to melt these sheets again and then use them in the project. The encasing of the adapter has been made of multiple layers of Polymorph which have been melted together. The encasing also holds the magnets for the docking mode option.
Result
The following images show the end result of our Motorola Milestone iPod dock adapter.
When the Motorola Milestone is connected to the adapter it will go into multimedia docking mode right away and start charging. After connecting the audio cable to the headphone connector it will output its audio to the dock as well. The Motorola Milestone is standing solid on the adapter and works great.
This article showed how to build an iPod dock adapter for the Motorola Milestone, however this information can easily be used to create adapters for other devices as well. If anyone is going to build a similar adapter for the Motorola Milestone or another device, I am for sure interested to know about it.
The adapter that I have built might not be the quality of an official one, but it is of course a prototype and it works pretty well. It probably is not going to happen, but I would really appreciate if any company out there would just build and sell adapters like this.
Thijs (Thice) Bosschert
http://www.thice.nl
I have wished for one of these! You are brilliant for creating a working model. Thank you for sharing your findings. Hopefully, these will come available for purchase!
Great work!! Thanks a lot for sharing… this comes in handy.
wow
les quedo muiy bien felicidades XD
Does the other end of the dock extender have the same sort of circuit board?
@gfrey
It sadly didn’t in the cable I used, it actually surprised me this side had. Maybe you have more luck in other cables.
Interesting & Thanks! The HTC Magic has the annoying HTC “proprietary micro-USB plus audio connector” rather than 3.5 or 2.5 mm audio.
It should therefore be possible to create a similar connector for my old Bose iPod dock, with the added advantage of not needed the separate audio cable. Maybe HTC did know what they were doing.
Hmmm – the only thing left to consider for the design is what artistic shape to make the polymorph encasing…
I wish you could do the same for htc magic and publish it here.
Anyway, this is fantastic and I like it!
@fast
I wouldn’t mind working out the same stuff for the HTC Magic, but I don’t have one. I do however have a HTC Touch lying around, which might have the same connector but runs on Windows Mobile. I will put it on my ‘possible future projects’ list
Any chance you are selling these adapters already made?
@Frank
At this moment I have no plans on doing that. But I will think about it, also depends on what you want to pay for it of course.
GREAT Product!!!! make for Incredible,… i’ll pay $50 plus parts!!!! for It!
I (stupidly) built an iPod dock into my car. It still looks good, but I don’t use my iPod anymore. Thanks to this brilliant idea I will build a Droid adapter to convert the iPod dock into a Droid dock. Thanks so much, I’ve already ordered my dock extension cable!
@p8ntblljnkie
I guess the Droid Incredible is a HTC device, isn’t it? In that case it would be the same approach as the HTC Magic requested above. I might look into that in the near future.
@Shawn
Please send me a picture of the adapter when you are done!
Great job, where did you place the magnets in the cradle?
I might have to run through this and see how it works. Thanks for the info and the great writeup on how to do it!!
@Chad
Above the micro USB connector a little more to the side. Slightly closer to the micro USB connector than the ideal location seen on the image above.
What about remotes buttons for docking station? I understand the station can receive and play audio. What would happen if someone tried using the remote to change the song while the motoroal was docked?
@Mike
Nothing, since the remote control wires are not connected (dock pin 12 and 13, Tx and Rx). As far as I have seen the Droid simply does not support any kind of remote control, so at this moment there is no way to get that working. However, I wouldn’t mind to be wrong there if anyone could show me otherwise.
Hi,
Very nice work. I’ve made a french translation in my website. I did not mention the polymorph encasing wich is device dependant.
http://yerffff.org/?p=67&preview=true
small error actually, the good url is http://yerffff.org/2010/06/19/tuto-utiliser-son-telephone-android-sur-un-dock-apple/
I rarely comment blogs, but this is genius! I built my dock from Lego, but my iPod dock/alarm clock sits empty since my upgrade to the Milestone. And this project gives me a valid reason to play with the POLYMORPH
Cheers
Dave
@Dave Landry
Please send me a picture of the end result!
Great article! I will certainly be trying this out.
I wish there was a way to get the data lines connected to also make a connector to convert all these iPod data cables I have lying around.
@Dan B
You can just connect the data lines of the dock connector on pin 25(USB data-) and pin 27 (USB data+). However on most docks this wont do anything since the devices are not compatible with each other. Cables should be a different story, it should not be any problem to connect the data lines there. However, it is probably easier and cheaper to just buy a micro USB cable in that case.
@admin
hi! man this is fantastic! i have a question for you, i am really hoping you can help..i have a milestone but i have seen an article on the web here, http://phandroid.com/2010/04/21/droid-incredible-does-tv-out-video/ it is about the incredible of course, doing tv out to show movies on the phone on a tv…and i want to get my phone to do this..can i build something to do that? i purchased the cable ,’HTC TV Out Cable – Original (OEM) TVC6850 ACT100′ from a company in the states..their page for it is here, http://www.wirelessground.com/tvoutact100.html
only problem is their ‘micro usb’ is for some reason different then the milestone micro usb..so im wondering if i just make an adapter for the end which goes into the phone, if that might be all it will take? it’s so frustrating when these companies don’t keep up with their own technology..they give us the phones capable of all this, but then not the cables!!!!! or the docks…. please help with any advice you may have..
thankyou jenna
@jenna
As far as I understood the Milestone does not support any way of video out, so the thing you requested is simply not possible.
well, i thought perhaps since i can use it through the computer and view movies off it that way, that i may be able to do it…plus i was just on a site here http://www.fommy.co.in/HTC-TV-Out-Cable-ACT100-P84453.htm and they have it listed ..the cable and for milestone as well….im just concerned as to weather or not it will work with mine from canada…..input port…. im waiting to hear back from their support..but if they offer the cable and for the milestone specifically, wouldn’t it mean that it can be done? also, i was wondering if the mirco usb port is different in the states then it is in canada?
Great work bro. I’m a bit confused why you had to use the 3,5mm stereo audio plug instead of being able to transfer the data information through the USB instead. can u please further explain that?
@jenna
The Milestone is made by Motorola and not by HTC. HTC uses a special hybrid USB port which also enables the output of audio and video. The Milestone only has a normal micro USB port and thus does not support audio and video out. As far as I know micro USB ports should be the same in any country, as long as it is a normal micro USB port that is.
@Ric
The micro USB port does not support audio and video, so the only way to get audio out of the Milestone seems to be by using the 3,5mm plug. The USB port can be used to transfer data, for example when connected to your computer, but that is not the same as getting an audio signal from it.
@admin
Thanks for the response. Any idea if the HTC EVO micro USB is any different
@admin
Thanks for the response. Any idea if the HTC EVO micro USB is any different
Hi fine………have some on trila this for the sonyericsson xperia x10?
@Ric
HTC EVO might sport the HTC USB hybrid port, if that is the case it should be possible to build an adapter which includes audio from that port as well.
@seb
I don’t understand your question and I am not sure what kind of connector the xperia x10 has.
Awesome – I’ve been thinking about hacking together a device like this myself.
A while ago I bought a cheap bluetooth stereo audio dongle that works nicely with Android – currently I have it plugged in to the aux in socket on an old set of ipod speakers. The only problem with it is that it needs to be charged over USB, so I have to keep remembering to charge it.
My plan is to hack it into a device like yours, and have it charge from the dock connector. The biggest question is how complex it’d be to wire up the dock’s play/pause/track skip buttons with the bluetooth dongle’s own buttons (which happily control the ‘droid’s audio player when connected) The dongle I’ve got has tiny surface mounted microswitches which would be somewhat tricky to desolder and replace – perhaps somebody knows an alternative?
If that all worked, then we’d have a nice universal dock adaptor that should work with any phone (certainly any android phone) without having to worry about the location of the headphone socket (or even have the phone physically docked, unless you want to charge at the same time)
@benjymous
Could you send me a link to the adapter you bought? Might be interesting to play around with.
@admin
Is there any way to create a similar adapter to connect my droid to my car’s iphone dock?
I have used this adapter: http://www.cablejive.com/products/Universal-Dock-Converter.html
but I am not able to get it to work in my 2010 VolksWagon Jetta or a 2010 Mercedes C300.
I think that the issue is with the car’s dock trying to verify a real ipod is connected. When I connect a real ipod to my VolksWagon Jetta’s dock I see the VW logo on the Ipod screen.
I was wondering if placing a resister on pin 21 of the ipod connection will trick the VW into thinking a real ipod is connected. Here is the pinout of the Ipod dock connector showing pin 21: http://pinouts.ru/PortableDevices/ipod_pinout.shtml
It’s labeled “Accessory Indicator/Serial enable”
Do you think this is the solution or do you have any other ideas?
Great idea! I do have one question regarding your prototype. I note that you are using the 3.5mm plug with 3 contacts and I am wondering if this is producing “stereo” results. Would you recommend using a 3.5MM 4 contact and leave the input channel null? This is the typical stereo headphone and mic set up providing Left channel audio output, Right Channel Audio Output, Microphone input and ground Do you think this will work and produce stereo results? Thanks for doing this it is remarkable work!
Could you please email me, I represent a company that may have some interest in your idea.
wow ,my god ,you are a talent!I am the supplier of charger and cable ,if you need some samples to do some test ,I will do it free for you .
Thanks ,my email:
@admin
Yup – it’s one of these:
http://www.amazon.co.uk/Nexxus-Bluemusic-Stereo-Bluetooth-headset/dp/B0036TGIOO
@Thurman
Take a look at the following post I made before on iPod authentication security:
http://www.thice.nl/bypassing-apples-video-out-protection/
I got the idea that the lock out has something to do with the authentication chip.
@Mark in Nebraska
Using a 4 contact plug should work since the normal headset that comes with the Motorola Milestone has 4 contacts as well. My approach should output stereo, and I guess using the 4 contact should as well.
@Mike
Done.
@James
Thanks for the offer, see you email. I removed your email address because of spammers harvesting it.
@benjymous
Thanks.
Dear Friend, maybe you can have it on the market!!!when you acheave ,pls tell me !!congratulations!!
@admin
Is that video out protection the same thing that I am dealing with on my Car ipod dock? The protection seems to be from the dock itself and not the ipod.
@admin
Is that video out protection the same thing that I am dealing with on my car’s ipod dock? The protection seems to be coming from the ipod dock itself and not the ipod.
@Thurman
Usually the protection is something between the iPod and the car dock, the dock needs to get the right information from the iPod which will give this after some kind of authentication I guess. Since I don’t own a similar system I can not investigate it further.