iPod dock adapter for the Motorola Droid/Milestone

Hardware, Mods15/06/2010

â€”> The PDF version of this article can be found here.

Manufacturers of electronic devices donâ€™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 â€˜Motorola Milestoneâ€™ 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.

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.

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

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

tom

29/12/2010

Why don’t you make those things and then just sell them? Because i want this but I now for sure that im going to screw it up.
Thanks anyways!
mlitty

01/01/2011

Just a quick correction/note. The image has USB Ground correctly at pin 16 and Vcc at 23, but the grid/text says has them reversed. I’ve gotten as far in the process as jumping 26 and 27, and wiring through Vcc and USB Ground, but my Droid X still will not power. Putting a multimeter on the leads, it looks like I’m only getting 1.5v out of Vcc. I’ve tried two different docs with the same results. My primary unit is a Bose rechargeable doc.
mlitty

01/01/2011

Cablejive has some interesting pre-made models. They don’t guarantee to work with all docs, but there are a variety of possibilities with their connectors.
Check this one out . . . http://www.cablejive.com/products/Universal-Dock-Converter.html
No, this is not spam, just my own attempt to alleviate frustration with my own inability to get this working.

Thanks for the post though, I’m glad this solution is working for some people.
Thice

05/01/2011

@tom
I already explained that a couple of comments above yours. I don’t have the time and I don’t think Apple would be happy with me making this, I don’t fancy having their lawyers over.
Thice

05/01/2011

@mlitty
You were right, the table was wrong, fixed it. Thanks.
I don’t own a Droid X or a Bose dock, so I can’t analyse what is going wrong for you. Did you also connect the Data- and Data+ of the USB port? It could be that it needs a resistor between those two leads. Best way to find out is to check what a normal charger does. I see no reason why your Droid X should not be able to be charged with a dock.
I did see the cables from cablejive, and while probably useful for some people it is pretty far from being a dock connector.
Matt

22/02/2011

This is an awesome idea, it is simple but effective. I built one today, and unfortunately it did not work. I have a samsung fascinate, and an ihome dock/radio/clock. I managed to get auido out, but had to turn the volume way up. It also would not charge. I measured the voltage out of dock and it was only 2.010 volts. I am guessing that there is some sort of sense enable on my ihome stereo. Unless it is just because I used a cheap dock cable, and the voltage drop across the pins was too much.

One thing I did notcie is that there is a surface mount resistor on the cable in your picture, but mine does not have it. As far as I can tell, pin 1 and pin 2 are both ground. So i’m not sure of the signifigance of this.

But for added props your idea does work, and I hooked 5Vdc to the usb connection with my power supply and my phone did start to charge. Just figured I would give you an update with a different but similar set up. Thanks for the awesome idea.
Thice

25/02/2011

@Matt
Do you have pictures of your project?
The SMD resistor in my cable is just seems to be a bridge, so it is just connecting pin 1 and 2. You might have to connect some wires together on the dock to get a higher output voltage. Best way to test that might be to connect an iPod and measure the pins.
Dockingstation mit Kompaktanlage – Seite 2 – Android-Hilfe.de

05/05/2011

[…] AW: Dockingstation mit Kompaktanlage Man kann sich einen Adapter iPod-Dock->USB+Klinke basteln und dann die iProdukte benutzen: Thice.nl iPod dock adapter for the Motorola Droid/Milestone […]
crafty

13/05/2011

hey love the write up got it to work with my galaxy s except i cant get sound! i heard bout connecting a 1k resistor onto pin 21 but my question is where does the other end go? and will this solve my sound issue?
Thice

16/05/2011

@crafty
I do not know the connectors the Galaxy S uses, so I am not sure why your setup doesn’t work. Could you provide me some more information and pin outs (throw in some pictures as well)?
crafty

19/05/2011

cant throw up any pics atm as im moving but basically the pins for sound is as follows;
pin 2 – earth (twisted wire sheath)
pin 3 – red
pin 4 – white

my phone charges without a problem so i kno that the microUSB end is fine. ive tried soldering the tx wires to the board (green blue from micro usb) aswell as twisting them together as per the diagram with no luck at all.

kinda frustrating as ive tried almost everything but still i have no sound coming out of my ipod dock
Thice

22/05/2011

@crafty
Are you trying to get audio out from the mini USB port? Because that won’t be possible (unless it is some hybrid port). When the phone charges the USB part is fine, you will need to connect the audio pins to the audio jack on the phone.
crafty

23/05/2011

no im trying to get it from the audio pins to an 3.5mm plug as described in the tutorial above. followed it to the letter but still no good!
Thice

24/05/2011

You might want to check the connector and pinout of your headphones to see if they differ from what I wrote in the tutorial. Drop me an email if you need more help on that.
Anonymous

13/07/2011

[…] […]
Matt the Beat

06/08/2011

This is what i need I will have to try to make one on my own as i recently purchased a car and it has an Ipod-phone what have you connector (i dont own an Iphone) but I have been using my phone by pluging in the audio into the AUX port on my car stereo but what I am missing out is the fact that this stereo was kinda made for an ipod(again i whaterver) as it has a cord in a nifty compartment i can essentually hide my i-phone connected device (this does not work with the aux port) it also has a remote control so i can controll all i-pod activities via the stereo as if the I-device is like a trunk cd player like thing. Well in short I would love to let my phone android based to have thiese capabilities.

The only other options I have are the following

1. get a dock plug in the aux and the power although this would use the one power port/ cigarette lighter i have in my car (i know one WTF this car is much nicer than my last and the last had the cigarette lighter power along with a secondary dual power ports giving me 3 power plugs (it was a GMC Sonoma MINI pickup- I liked it but it got totaled and only had all factory stuff the new car is a Subaru and has a lot of options but only one power port)

2. use the aux and power plug without a dock

3. Make what you have going on (MY GOAL!!!) then i would be golden I will hope i can do this myself if anyone can help (maybe make one and ill buy it???? if its quality and can meet my specifications. if your interested in making $20 materials paid for (ill pay for everything needed but oonce only thats why i want someone else to do it so i dont mess it up and have to buy multiple cords and such)
loubieelou

26/12/2011

i’m slightly confused, do you have to cut the casing on the stereo and micro usb cables and soldier the wires inside to the dock connector? help please…
Thice

30/12/2011

@loubieelou
Yes, you wire the cables to the dock connector, it should be pretty clear after reading the full article.
Maaaatt

11/09/2012

Thinking of a slightly different take on this for my Xperia Arc S, using a iPod nano dock adapter as the base, and possibly acrylic as the cradle. Keep an eye on my website, and I will make sure I credit you for the original plans.
Thice

11/09/2012

@Maaaatt
Your website doesn’t seem to work here. Please let me know how your project works out!
Since I switched from my Milestone to the Droid 4 I need to build a new adapter myself as well.
Parth

23/09/2012

How can i get iPod 6th generation dock male connector dimensions?
I want to mount this connector on PCB. And from where i can get PCB mountable dock connector?
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