Dock Pinout

[Glithramir]

Hi.
Does anyone know or can find out exactly what the three pins are used for? +5v, GND and control(and how to us it)?

 

[ztm.000]

Hi.
Does anyone know or can find out exactly what the three pins are used for? +5v, GND and control(and how to us it)?

ummmm..... seriously?

 

[Glithramir]

Yes, If I ever want to build a custom dock or whatever.
I have searched and found no documentation about the small docking pins so far.

 

[SilentMobius]

I second this.

I'd like to know which is +5v, gnd and what resistance (to ground) is expected on the control point to mimic the desktop dock

 

[DayBlur]

My results

I plan on making a charging-only dock as well. Here's what I measured on the Google dock pins (my numbering).

1 - 5V
2 - CTL

(mic port)
3 - GND

There's about 5.2V (no load) at the dock between pins 1 and 3. The dock also measures 10kohm between pins 2 and 3. It seems pretty straight forward, and there don't seem to be any other interesting or unexpected voltage or resistance values between other pin combinations.

The phone does start charging fine when applying an external 5V on pins 1 and 3, but I have been unable to force it into the dock mode. I have connected an external 10k resistor between pins 2 and 3 both with and without power applied to the charging pins with no luck. Any ideas? I just played with it for a few minutes, but I'll post if I figure anything out when I get back to it.

 

[diversificationied]

When you manually put the charge on, does that affect the bluetooth settings?

I'm thinking maybe when it has a charge through the pins it activates bluetooth so it can pair with the docks bluetooth, and that activates the dock mode?

 

[Red MacGregor]

nexus dock

is pretty damn cool...

when i get a chance this weekend, i'm going to hook up a meter to the pin-outs and see what it's doing with the 3rd pin to force clock mode

 

[mautai916]

that would be awesome

 

[dhendrix11]

Ok so after reading some dock threads, I decided to contribute something useful to the discussion by taking my dock apart. Unfortunately, what I've found is bad news for a simple DIY dock. The middle pin looks to be a bit pattern toggled by the dock upon insertion of the phone.

The bottom trace is the full signal toggling. The top trace is zoomed in on the left side of the bottom trace.

 

[Glithramir]

Thank you very much!! Too bad tho...

 

[rotohammer]

Unfortunately, what I've found is bad news for a simple DIY dock. The middle pin looks to be a bit pattern toggled by the dock upon insertion of the phone.

I interpreted the binary pattern, its saying "F*ck Apple"

 

[Red MacGregor]

grumble grumble..

beat me to it.. working too many hours for hobbies..

 

[DayBlur]

Awesome, thanks for the info. I haven't been able to get back to additional testing or taking mine apart yet.

1. How hard was the dock to take apart? Did it just require peeling off the rubber bottom and removing screws, or something more destructive?

2. I was wondering if you could post or email a higher resolution image of your annotated board layout - I couldn't quite make out some of the text in the upper left.

3. Does that bit pattern ever change, and is it bi-directional? That delay in the middle makes it look to me like a challenge-response. My random guess is that the phone sends that first pattern when it gets power on the dock pins, and then the dock (if connected) responds with some kind of identifier (home/car/etc). It should be pretty easy to replicate such a static pattern/response with a simple microcontroller...

Thanks,
James

 

[dhendrix11]

Awesome, thanks for the info. I haven't been able to get back to additional testing or taking mine apart yet.

1. How hard was the dock to take apart? Did it just require peeling off the rubber bottom and removing screws, or something more destructive?

2. I was wondering if you could post or email a higher resolution image of your annotated board layout - I couldn't quite make out some of the text in the upper left.

3. Does that bit pattern ever change, and is it bi-directional? That delay in the middle makes it look to me like a challenge-response. My random guess is that the phone sends that first pattern when it gets power on the dock pins, and then the dock (if connected) responds with some kind of identifier (home/car/etc). It should be pretty easy to replicate such a static pattern/response with a simple microcontroller...

Thanks,
James

1. It was very easy to take the dock apart. Remove 4 screws under the rubber bottom and you get to the PCB. Remove 1 screw to take the pcb out. You can disconnect the wire harness that connects the PCB to the 3 dock pins very easily.

2. Original high res photo is in the attached zip file.

3. I hooked 5V between the pwr and gnd pins on the phone without the dock, and a 10k resistor from the middle pin to GND. Upon connecting the 5V, the phone outputs 9 pulses @ 25Hz. However, that doesn't really jive with the timing from my previous scope captures, so maybe I wasn't looking at the whole picture connected through the dock. I don't feel like taking my dock apart again tonight, but I'll see about some further investigation this weekend.

 

[tiberiumx]

Anyone have a logic analyzer? The transferred data could be captured and decoded. It probably wouldn't be too tough to code up a microcontroller to interact with it for a DIY dock if we knew what it was saying.

If anyone wants to send me a dock, I could hook it up to mine and try to get a binary dump.

 

[rotohammer]

The previous image of the waveform looks like it could be a "tone burst", or being square wave, its just 10101010101010101010.

It could be used to prevent bounce using a simple circuit on the recieving side like this:

                                               ________
in                                    out  ____|      |_______
>------||--+----/\/\/\/\------>
           |
           +---||----+
              +      |
                     |
                   GND

 

[dhendrix11]

Here are some better scope captures. The 25Hz pulse train output from the phone only occurs if it's not connected to a dock. If there's a dock present, you get the bit patterns from my original post.

Next I have to figure out if this is bi-directional.

 

[rashid11]

N1 is prolly sending the bursts every few secs, so that when it is placed into a dock, the dock detects presence of N1.

This is where it could get interesting. Since N1 communicates to the dock via BT, it might need to know the dock's BT Device ID (MAC-address-like) - so that it doesn't end up pairing with a different dock that your coworker has in an adjacent cube . So may be what the dock sends back after detecting the N1 is in fact its BT ID ?

 

[brotbuexe]

This is where it could get interesting. Since N1 communicates to the dock via BT, it might need to know the dock's BT Device ID (MAC-address-like) - so that it doesn't end up pairing with a different dock that your coworker has in an adjacent cube . So may be what the dock sends back after detecting the N1 is in fact its BT ID ?

http://android.git.kernel.org/?p=ke...334736426c8b33;hb=android-msm-2.6.29-nexusone

Could this source explain whats going on?

 

[rotohammer]

http://android.git.kernel.org/?p=ke...334736426c8b33;hb=android-msm-2.6.29-nexusone

Could this source explain whats going on?

It sure looks like it. It looks like the signal is a 1 wire interface, using MFM encoding to send a small set of commands and results back and forth between the dock and the phone.