Mobile Linux Devices >> Other Android Mobile Phones and Tablets >> Dell streak's line-out

Message started by serenith on Feb 15th, 2011, 11:53am

Title: Dell streak's line-out
Post by serenith on Feb 15th, 2011, 11:53am

Hi John,

I appreciated your articles on the Streak's dock and modded PDMI cable.  I'm interested in modding a cable as you did and extract a min-usb and an analog line-out from the PDMI connector.  However, it seems that this is not a straight-foward mod: People who bought the Slacker G2's dock say that while they can charge their Streak using the PDMI connector of that dock, the dock's line-out socket isn't delivering any sound.

I don't have access to any of these two docks, but it was proposed that the Dell dock might communicate with the Streak to switch on or off the audio output on the line-out. Do you still own the Dell dock and can you see any evidence of that kind of communication? I'm hesitant in starting to short pins on an open pdmi cable to see what happens.


Title: Re: Dell streak's line-out
Post by Administrator on Feb 17th, 2011, 12:41pm

I did not detect any "smarts" in the dock that could be communicating with the Streak.

That said, there are many ground pins on that HDMI connector.  It is very likely that the dock or other peripherals are identified by combination of those ground pins.

When I put the Streak in the dock, It gives me an option to mute the sound, with 2.2, it now also goes into docked mode (the clock app).  When I connect my mini USB adapter (with or without being connected to USB power), it does not do this.  This means it knows when it is in the dock.

With due diligence,  it should be safe to try different ground combinations.  I would not just do it randomly, and I would not connect to anything but ground.  For example try grounding ground pins in groups,  for example what happens if you connect the 2 high current grounds? (7, 16)  That would probably only happen in a dock (I don't think HDMI High-current Power cables were ever planned or made.)

I would also like to make an Audio cable so that I can connect USB power and the audio with one connection in the car.  If I ever get around to this, I'll post what I find.

Title: Re: Dell streak's line-out
Post by Zandar on Jun 24th, 2011, 3:18pm

I'm also very interested in doing something like this. I'll be following to see if there's any progress made (and I'll also be sure to post should I have any progress; in the midst of trying to self-teach Linux and Java, so I don't know if self-teaching hardware mods will be in the cards just yet  ;D ).

Title: Re: Dell streak's line-out
Post by ostranenie on Aug 18th, 2011, 1:55pm


I'm interested in making a one-off PDMI to HDMI cable for the Dell Streak (If we are picking nits, it's going to be a PDMI to DisplayPort to HDMI cable--see below). I refuse to pay $50 for some copper, a piece of shiny molded plastic and a few resistors and caps. However I do want to display my Streak 5's output on my TV, if only to view photos and videos with the inbuilt video player. (I'm crossing my fingers for NetFlix, but I'm not holding my breath.)

I'm assuming the following:
- PDMI has a bunch of stuff (USB 2.0, USB 3.0, analog, audio, DisplayPort)
- DisplayPort is a subset of PDMI (well, kind of; PDMI only uses two of its four 'lanes' and the auxiliary lane)
- DisplayPort isn't officially HDMI-compatible but can detect VGA, DVI or HDMI and output the appropriate signal - maybe through the 'Hot Plug Detect' pin?
- The Dell Dock has no active circuitry; the DisplayPort-to-HDMI conversion is done on the Streak itself
- The Dell Dock with HDMI out has some pins grounded (which pins?) that trigger the "Wanna display HDMI?" software controls on the Dell Streak's firmware

Anyway, my plan is to buy a $5 PDMI-to-USB cable and a DisplayPort-to-HDMI cable. Based on the specs and pinouts for PDMI, DisplayPort and HDMI, I will attempt to hook the thing up to my HDMI TV. I am also going to break out and ground random grounds on the PDMI cable together (as John suggests above) to see if I can get the Streak to respond appropriately.

I'll report back here soon. Wish me luck! (And if anyone who owns a dock wants to put an ohmmeter to any of the ground pins on the thing--that'd be 2, 7, 13, 16, 18, 25, 27 and 29--I'd love to hear which ones are fused together ;-) )

PDMI spec:
DisplayPort spec:
HDMI spec:
DP-to-HDMI adapter ($3-5 w/shipping):
Streak USB cable ($3.50 w/shipping):

Title: Re: Dell streak's line-out
Post by ostranenie on Aug 18th, 2011, 2:26pm

Also: chart.

30Main Link Lane 0 +1
28Main Link Lane 0 -3
26Main Link Lane 1 +4
24Main Link Lane 1 -6
20Hot Plug Detect 18
25, 27, 29GND2,5,8,11,16,13?,14?,19?
21AUX CH+  (Necessary?)15
22AUX CH- (Necessary?)17
23DP_PWR  3.3V (Necessary?)20
GND / NC?Config 1  GND13
GND / NC?Config 2  GND (or CEC for HDMI)14
GND / NC?Power Return19 (GND?)
NCMain Link Lane 2 +7
NCMain Link Lane 2 -9
NCMain Link Lane 3 +10
NCMain Link Lane 3 -12
Other PDMI Grounds:

2USB 2.0 GND
7, 16High current ground
10Audio out ground
13, 18USB 3.0 GND
4USB OTGLeave floating? Ground?

Title: Re: Dell streak's line-out
Post by ostranenie on Aug 18th, 2011, 2:30pm

USB spec here, also, for posterity:

Title: Re: Dell streak's line-out
Post by peterindigital on Aug 27th, 2011, 2:24am

hi ,i found this     i don't know if this will work with dell streak

Title: Re: Dell streak's line-out
Post by tdashmike on Sep 14th, 2011, 7:22am

Well today I tried putting 3.3V on the Hot Plug detect pin and it didn't do anything. Also tried measuring pin 23 which should have voltage but it didn't. I would really like to make my own cable so that I could use it in my car.

Can someone take some really detailed photos of the dock PCB board? Detailed enough that I can see where the traces are running.

Thanks in advance!

Title: Re: Dell streak's line-out
Post by j2daf on Sep 29th, 2011, 9:40pm

I have been hunting up and down for resources to help make a pdmi to usb/audio out cable.  I have the audio working fine when the cable is plugged in by tapping pins 8,9 and 10 but sound still was still coming from the speakers.  Luckily by accident, i shorted pins 9 (audio left out) and 7 (DGND / HC GND)  and  dock mode was triggered and i was able to disable internal speakers.  I'm assuming DGND is dock ground...but the problem now is I'm not able to charge.  HMMMM  Maybe this new post will spark some life here

Title: Re: Dell streak's line-out
Post by JohnMo on Nov 17th, 2011, 5:29am

Hi Guys
Have you made further progress??
Is there confirmation for:
Pin 7 = Grnd
Pin 8 = Right audio line out
Pin 9 = Left audio line out
Pin 10 = Audio ground
Shorting Pins 7 & 9 starts docking mode, so the built in speaker can be shut off ??
Alternatively, any ideas as to which colours are which in the OEM cable?
I will happily sacrifice a cable if I know which is which!
Many Thanks
Good luck with this, as if it can be done, I and my ears will be SO happy !

Title: Re: Dell streak's line-out
Post by jamisonmp on Jan 9th, 2012, 12:57pm

I have confirmed that the audio out pins correspond with the standard PDMI pinout and function as they should. I have two issues with this.

I've put my PDMI cable together but I can't seem to pinpoint how to get the phone to mute the internal speaker. I've tried pins 7 and 9 and all that does is kill the left audio channel. I've also tried bridging both pins 7 and 16 and it had no affect either.

And there seems to be a direct volume control from Android and the Hardware, and usually a line out has no volume control at all, which leads me to believe that this is not a true line out but just another amplified audio output like the headphone jack.

If someone could point me in the right direction as to what pins control the phones dock mode/Speaker mute (or if it is even possible). Thank you. Forums » Powered by YaBB 2.1!
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