[Q] hacking docks to provide audio, hdmi or sync (MHL and stuff)

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I've spent some time searching looking for something on the subject, but haven't found anything that seems to cover it (does that make me special (I did laugh at the video), but enough off topic).

so I specifically have the Samsung Galaxy Note. though I realise in a lot of ways its really just a big S2 in most regards. and I suspect several other devises that would be comparible.

I'm currentlty using a dual charging dock station which I bought cheaply of amazon, and that gives me sync and power. having looked inside the case there loads of spare room in there. and so I'm wondering about playing around with the MHL adapter and ideally something like the audio out with the official samsung dock.

from what research I've done the note senses what type of dock its in by the resistance on pins 4 and 5. now even with my basic electrical skills it seems rather easy to put in a 3 way switch to select between these

obviously the guts for the HDMI out would be from a MHL adapter, and that should be possible to power through the standard connectors on the current dock. but what I cant seem to find would be the associated parts for the audio (dont want to buy the official samsung dock just to rip it apart) (one thread on here about stripping the cable back to power and then the 3 inner wires were left, right and ground, but didn't see any evidence of that method working)

the audio aspect has another relevence for me, as I'm also wondering about a note dock/speaker set up (cheap 2.1 speakers, rehouse the sub to a case that incorperates the mUSB connector, audio components, and power, so that other than speaker cables and one power cable that'd be it (currently use a Sony NWA-3000 plugged into old pc speakers for such night time listening)

so thoughts and advise (specifically on the audio aspect)

Thatz pretty impressive. I too have that sony dock. I think about modification of it so that i can plug in my hd2 in it. Ie just to put an micro usb plug out from it, so that i can charge my phone while i plug in 3.5mm jack from the sony dock.

Thatz all about mine.. now letz look into ur case.
Cant u try out 3.5 mm jack for audio o/p?
Or else u can check out pinouts.ru for pin config of hdmi, coz, u r going to take out hdmi from sg note any way. So u can rip the cable apart and take out audio and video wires, connect the video cables to tv and audio to dock/ amp.

But i suggest that 3.5 jack will be the easier way.

Sent from my HD2 using XDA App

So I don't know about it, I would say that it really isn't that feasible. Besides putting a different resistance you would also need to route the data lines to a different location to the MHL to HMDI converter.

If you were to do the video or USB you couldn't do audio. From what I understand there is a IC that looks at the resistance on the ID pin and puts the audio signals on the data lines. Once again you run into the same problem that you have with the video adapter, routing the data lines.

got a brief schematic for layout. I'm buying some cheap bits now (MHL adapter, USB soundcard, USB OTG cable)

first a few explanations on the schematic, software I used didn't have many switches on it, so plan to use a 4 pole double throw like this rather than the 2 sets of 2p2t shown in the diagram

secondly, not sure if I need to short pins 4&5 for OTG, still reading stuff

Yap, u got it.. but also provide external power supply of exactly 5v in usb host mode, so as to power slave devices.

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guyz, i wanna ask something, in order to use MHL adapter, does the phone need to support MHL protocol? and the protocol resides in the hardware part or software part of the phone?

The MHL lives in the phones hardware is the simplest. If you find the Galaxy S2 hack pack it will show you a block diagram of how the MHL exists there.

Originally Posted by syin16

guyz, i wanna ask something, in order to use MHL adapter, does the phone need to support MHL protocol? and the protocol resides in the hardware part or software part of the phone?

as giritrobbins said it is hardware based.

it shares the microUSB connector, but uses an entirely different signalling. hence why it has to be separated out. otherwise a hub would do every thing I'm trying to do here

Hi, folks just thought I would ask how this project is going ? It's really quite fascinating.

Pin 5 (ground) can be carried through to everything.

OTG requires ID (pin4) to be connected to Gnd (pin 5).

In the diagram above S2 is not really needed.

If you want to switch electronically, there are lots of ICs for doing that.
Here is one picked entirely at random: http://www.fairchildsemi.com/ds/FS/FSA3000.pdf

MHL will be the trouble spot, USB is much more forgiving.