Related
Having previously owned a IIs and having a standard usb cradle in my car run from a usb connectored "cigarette lighter adapter", I'm used to using my devices as a portable "car stereo". I even wired it up to replace my old crap car stereo, using a small "cheap boy-racer style" £30 stereo power amp under the dash. This has been great for the last year. I get in the car, dock the xda IIs into the cradle, plug in the headphone socket which is wired into the amp and hey presto, music - and tom tom prompts through the car speakers.
Recently I've been eyeing up the xda exec(JasJar/Universal) and after getting a second hand colleague to buy my IIis, decided to get the new device. Obviously the shorter battery life is a bit of a shock compared to my old one, but I was pleasantly suprised that
1) The audio output seems a better quality
2) The new device no longer needed a custom USB cradle plinth or gooseneck holder, ... I could place the "open clam" in the recess in my instrument panel, to the right of my speedo. Basically sitting just behind the steering wheel, which also solves the night-time reflection issues of a bright display.
Just one problem, I discovered that the USB sync cable supplied with the new device doesnt seem to enable charging to the exec when I plugged it into the 12Volt to USB adapter that worked with the XDA IIs that I wired into my dashboard.
So I decided to buy a new car power adapter for the new Exec, egged on by installing the great "mort player" which has an ideal "large button" interface on a black background which is ideal for use in the car.... and it doesnt forget the playlist like media player 10 seems to do each time you run it...
However, When the car power adapter arrived today, (from expansys)
http://www.expansys.com/product.asp?code=125511
To my dismay it is very noisy! the audio output to my amp sounds great with just the headphone output to my mini under dash amplifier, but only on battery power. But when the adapter is supplying power, the audio output becomes "crackly" Any electonics boffins have any suggestions to remove the "noise" with capacitors, if so what type and where should I put them, on the audio, or inline with the cigarette power adapter dc input somewhere, or should I just send it back and try and source a better quality adapter?
Expansys also do 2 other models -
http://www.expansys.com/product.asp?code=125969
http://www.expansys.com/product.asp?code=125970
Does anyone know if these are as noisy as the other one? Does anyone else have a similar setup?
Thanks in advance
Derek
you have a ground loop. in america, we use negative as the ground, so be carefull with what I'm telling you (posative is ground in some countries).
What you need to do is run the amp and cigarette lighter off the same ground(s) and possibly the same feeds (supply voltage). Make sure you fuse the lines appropriately, or you might fry something.
I would suggest installing a secondary cigarett lighter outlet somewhere convenient (so you don't cross any other circuts in your car, and burn stuff out), and run it off the same points that your amplifier gets it's power. Fuse the new outlet with the appropriate fuse (should be 5 or 10 amps), and give your new setup a whirl. It's a cheap alternative for you to try (should be about $10 or 8 euro?)
Good luck, and remember, NOT MY FAULT WHAT YOU DO> TRY THIS AT YOUR OWN RISK!!!!!!
I agree with him ^
JAmes
Strangely - today the noise is gone... hmm... very strange...
perhaps it was a solar flare, or another explosion at hemel
or more likely - perhaps there was a loose connection somewhere!
Thanks for all the advice guys, I will certainly make sure I avoid any ground loops and ground the audio on the same physical connection as the car earth. I'll check this at the weekend when I have some daylight to work in!. I'll do this when wiring the new adapter in properly - I can't bear it hanging out of the lighter socket with the near the indicator stalk!
I can say the Exec is great device though... Its a far better solution for car audio - and no leaving an expensive hifi in the car to be stolen.
Hopefully someone else is inspired by this post to also use the device in this way. If you want plenty of storage for a full install of the tomtom uk map and loads of music, you'll be interested to hear that you can actually get a 2 gig card now from ebuyer for about £60!
http://www.ebuyer.com/customer/prod...vd19wcm9kdWN0X292ZXJ2aWV3&product_uid=103013
Cheers
Derek
This is very valuable info
interestingfellow said:
you have a ground loop. in america, we use negative as the ground, so be carefull with what I'm telling you (posative is ground in some countries).
What you need to do is run the amp and cigarette lighter off the same ground(s) and possibly the same feeds (supply voltage). Make sure you fuse the lines appropriately, or you might fry something.
I would suggest installing a secondary cigarett lighter outlet somewhere convenient (so you don't cross any other circuts in your car, and burn stuff out), and run it off the same points that your amplifier gets it's power. Fuse the new outlet with the appropriate fuse (should be 5 or 10 amps), and give your new setup a whirl. It's a cheap alternative for you to try (should be about $10 or 8 euro?)
Good luck, and remember, NOT MY FAULT WHAT YOU DO> TRY THIS AT YOUR OWN RISK!!!!!!
Click to expand...
Click to collapse
Indeed! http://en.wikipedia.org/wiki/Ground_loop_(electricity)
I have a a USB mini extension lead, so I'm trying to plug in a 3-to-1 adapter to it. So male USB mini, the a-symetrical type (flat one side) to a female USB mini, the symetrical type (wings on both sides). Obviously this doesn't fit!
So is there a USB Mini (female a-symetrical) to USB mini (male symetrical) adapter?
Or could someone at least tell me their proper names so I can google it?
What are you trying to achieve? If it is to increase the cable length between the 3in1 and the Kaiser, I think you would need an ExtUSB patch lead with all 11 pins wired to retain the functionality of the 3in1. I don't know if these leads even exist.
The Asymetrical female socket, like the one on the base of the Kaiser, is double sided on the internal plastic "island" and has 5 contacts on one side and 6 contacts on the other.
The power and data are on the top 5 connectors.
The audio in/out & talk/end are on the bottom 6 connectors.
This is known as ExtUSB and is peculiar to HTC devices.
The Symetrical plug/socket is standard mini USB and will only ever have power and data connections. The mini USB plug only connects to the top 5 connectors in an ExtUSB socket.
Ouch, my dreams of the perfect in-car system dashed! Thanks wizzard that's really explained it very well.
The objective is to have a nice looking car install with only one wire leading to the Kaiser, and the 3-in-one hidden. So ideally:
Power \/
Audio > 3-in-one >> USB extension >> Kaiser
Hands free /\
It was hard enough finding the mini USB extension, so as you say an ExtUSB extension lead may not even exist
I purchased this adaptor for less than £10 from ebay. It ticks all the boxes for me and is the most discrete adaptor I could find. The 3in1 adaptors like this one dont come with a mic so wont work as a hands free without additional adaptors.
My intention is to have the plug fixed to a Brodit mount. The cable is no thicker than headphone cable. This 90cm cable will route to behind the steering wheel on the cowling. The adaptor is flat and low profile with the answer/hang up button on the top. Easily pressed through the steering wheel spokes. The audio 3.5mm and mini USB leads plug in at right angles to each other but will easily route out of site, behind the dash to USB car charger and 3.5mm MP3 In socket on the head unit.
It all works as expected, and even at Motorway speeds callers can hear me clearly. Voice Command works fine, TomTom and Media Player sound great. My only problem is alternator whine when charging, which I think is just an earthing problem. When I get it all properly finished I will post some photos.
After work, wife, kids etc. have finished with me.
Thanks Wizzard. Not a bad solution, and the best so far without the existence of an ExtUSB extension lead.
My only problem with it is that (I assume) it forces the kaiser into handfree mode even when all I was to do is charge and listen to music from the 3.5mm connection.
Again, I am assuming here, but I thought the second adapter you cite would only initiate hands free when I plug in the hands free into its port. I could be wrong on that one though.
Perhaps my issue is a small price to pay for 8gbs of music in the car
foaf said:
I thought the second adapter you cite would only initiate hands free when I plug in the hands free into its port.
Click to expand...
Click to collapse
I dont have the bulky 3in1 to test, sorry. For me when listening to music and TomTom the audio mutes when I take a call and then resumes seamlessly on hang up without needing to physically touch the Kaiser. I only need to touch the Kaiser to press the Voice Command key once to launch programs and initiate calls.
wizzzard said:
I purchased this adaptor for less than £10 from ebay. It ticks all the boxes for me and is the most discrete adaptor I could find. The 3in1 adaptors like this one dont come with a mic so wont work as a hands free without additional adaptors.
My intention is to have the plug fixed to a Brodit mount. The cable is no thicker than headphone cable. This 90cm cable will route to behind the steering wheel on the cowling. The adaptor is flat and low profile with the answer/hang up button on the top. Easily pressed through the steering wheel spokes. The audio 3.5mm and mini USB leads plug in at right angles to each other but will easily route out of site, behind the dash to USB car charger and 3.5mm MP3 In socket on the head unit.
It all works as expected, and even at Motorway speeds callers can hear me clearly. Voice Command works fine, TomTom and Media Player sound great. My only problem is alternator whine when charging, which I think is just an earthing problem. When I get it all properly finished I will post some photos.
After work, wife, kids etc. have finished with me.
Click to expand...
Click to collapse
Hi!
Unfortunately the link to the item you have is broken...
I'm trying exactly what you wanna do, I bought this extension.
Is this the same of you?
It works, but I have annoying noise on audio when it's connected to the USB power jacket.
How to fix this?
Thanks a lot.
I can't seem to locate the thread I saw a while back regarding someone wanting an extension cable for the T.V. out USB dongle for a Fuze.
I also wanted to port into my car's radio (touchscreen w/audio & video in/out jacks) and also supply power without having a tangle of wires. The t.v. dongle has a power-in jack on the side but that would result in a mess and I, apparently not alone, was looking for an 11 pin miniUSB extension cable. Seems nobody can find such an animal. However, during a trip to WalMart I found a car charger adaptor for Motorola phones with a 90 degree plug and a coiled cord. Not quite as neat as an extension would have been but with the jack arranged to point down the side of the dongle, the coiled portion can wrap around the dongle's cable. $15 and the search was over.
Heelo beav12
I was probably the one looking for the cable. I have my Fuze in a cradle in my car and I have the HTC A/V cable plugged into the bottom of the cradle so when I slide my fuze into it, I get connection to my Avic-D3 and I can see whatever the fuze sees on the Avic screen. However, in order to keep the phone charged, I have to plug in another cable into the jack on the little junction box and now I have 2 cables and an ugly box hanging below my phone.
I have searched high and low for an 11 pin mini USB extension cable to no avail and the 2 different styles of A/V cables for the phone either have the junction box 2-3 inches from the end where it plugs into the phone (which is what I have now) or if the junction is at the other end of the cable by the RCA plugs, it lacks the charging port! HOW F$#@$%ing dumb are these engineers??? All I want to do is hide the mess behind the dash and have just ONE SINGLE CABLE running up to the phone cradle.
If anyone has any ideas before I start cutting and soldering, please let me know!
Thanks for such a GREAT site here and hopefully someone will come up with a solution besides cut and burn!
Good day to all!
ITAdmin
This is my first post with links and info and stuff so please don't mind the bad formatting or other errors.
I bought a docking station a bit back and tore it down; I'm not very impressed but I'm sure we can make something of it.
Dock:
Connector and IR:
Connector - Top:
Connector - Bottom:
Mainboard - Top:
Mainboard - Bottom:
As you can see on this unit there isn't any HDMI however the board was made for it. Also of note is the HDMI pins on the ribbon cable.
I've checked and the nuvoTon (W78E052DFG) is an 8052 with 8KB flash and 256 bytes ram.
The audio portion seems to have a filter set on it however I don't believe it's amplified.
I have not been able to determine if there is or isn't USB on the ribbon cable or connector though there's no sign of it on the board.
Another point is I've switched to a custom rom and it no longer detects the dock. I noticed before switching that there is a service that watches for the dock and I'm guessing sends a signal to android to start the media app on dock. Virtuous XooM does not in any way detect connection.
Communication with the 8052 is through serial and the kernel source shows info about it. I haven't been able to find any reference to USB. if USB is present I'd expect it to be the pair near pin 30.
(All images taken with the A500 camera)
------- New info: (copied from later post)
This is the dock pinout as seen by the tablet (other devices may have different pins connected)
1-10 no connection
11 - unknown - traced to Q9 near IR connector on dock but unable to find past there (2v from tablet)
12 no connection
13 - audio connect of some sort - appears to be connected to left channel (after capacitor) through a 1k resistor
14 - Right audio - decoupled with 100uF
15 - Left audio - decoupled with 100uF like right channel
16 - Audio ground - not connected to main ground
17 no connection
18-20 +12V
21-30 HDMI - NO signals connected except GND at 21,24,27,30
31 - unknown - 3.3v from tablet
32 - TXD pin on 8052 through a level converter
33 - RXD pin on 8052 through a level converter
34 - unknown - 0v - 3.3v when dock unpowered but tablet connected so this may be a dock detection
35 - connected to 33 on tablet side
36 - connected to 32 on tablet side
37-40 no connection
These are all assumptions based on zebra cable layout so are quite probably wrong. They are also numbered based on the ribbon cable and I haven't made a conversion between ribbon cable and connector.
A voltage readings were done with an uncalibrated DMM on an oscilloscope (which seems to be .2v off or more). If i mark "from tablet" it's because it's not live when tablet not present and live even if power is disconnected from base.
1 case ground 0v
2-7 serial port(0v across)
8-20 HDMI
21unknown 3.3v from tablet
22 unknown 2v from tablet
23 unknown 2v from tablet
24-25 audio - audio even when nothing plugged in 0v
26 audio ground 0v
27 unknown 2v from tablet
28 unknown 0v (3.3v when dock unpowered but tablet docked)
30-35 12.0V
37 unknown 0v
38-40 gnd
Audio pins are correct but I can't tell which channel is which without finding a mp3 with audio only on one side. I would also trust the HDMI pins as ballanced pairs with shield between running directly to the HDMI portion of the board does seem rather proving.
None of the pins really look like USB as they should remain at 0v until a device is plugged in. I'll test connecting a 1500 ohm resister to 3.3v while monitoring the pin under test and see if I can find a USB connection attempt that way. If that doesn't work, finding pins with 15k ohm to GND would also indicate USB and I can try connecting a device to those.
Just recieved mine today from Amazon (they went on sale, so I figured I'd bite). No HDMI is disappointing, but not a dealbreaker for me.
Oddly enough, my biggest complaint is that it doesn't come with it's own power cable. I was hoping to leave the dock hooked up at home, and be able to pack the (INCREDIBLY SHORT) A500 power adapter in my bag for when I go out. Looks like it's back to eBay for another...
Excuse my off-topic mini rant. The teardown is appreciated. Curious if you ever did find anything with the USB pins.
I've read there are 2 versions of this docking station, one with HDMI and another without. It seems a lot of sellers are advertising the HDMI version but when people receive it, they get the non-HDMI version instead. Seems it's a hit or miss if you buy it online, probably safer to buy it from a brick & motar store so you can verify which version you're actually getting.
Sorry for off-topic too, just wanted to warn those that are thinking of getting this docking station
Nice tear-down btw.
Any idea what the part number for the connector itself is ? I am interested in a custom dock setup and all I am concerned about its power, however I need to find the mating connector to integrate into it.
Any info is appreciated!
Jeff
Quality of the photo surprised me !
So, any more info on this? I am putting an a100 in my dash, and I would like to use the dock connector at some point. For now I'll just run the power and audio through their ports I guess, but I would like to simplify the install at some point.
If these things suck so much, hopefully the price will drop soon, and I'll feel comfortable buying one to take apart for experimenting myself.
Thanks!
endoracing said:
Any idea what the part number for the connector itself is ? I am interested in a custom dock setup and all I am concerned about its power, however I need to find the mating connector to integrate into it.
Any info is appreciated!
Jeff
Click to expand...
Click to collapse
There aren't any identifiable markings however I think I found the right connector by checking some of the vendors who make 'em. I'm almost positive the connector is: JAE - DD2 Series
This means that there's also a cable variant of the dock side connector, cool eh?
I have not measured the connector to see if the dimensions are correct but the pitch, count, offset appearance and overall appearance are perfect matches. Even the slits cut into the top of the tablet-side connector match what's in the drawings. Still not a guarantee, but good enough for me to buy a couple to see if they match.
Here are the digikey parts:
PCB connector - $7.67 in singles
Cable connector - $10.67 in singles
Acer make two docking station models:
LC.DCK0A.001 without hdmi http://www.aceronline.es/shop/docking-station-para-acer-iconia-tab-a500a100-lcdck0a001-p-3786.html
LC.DCK0A.002 with hdmi http://www.aceronline.es/shop/docking-station-para-acer-iconia-tab-a500a100-lcdck0a002-p-3787.html
HDJ80 said:
Acer make two docking station models:
LC.DCK0A.001 without hdmi
LC.DCK0A.002 with hdmi
Click to expand...
Click to collapse
Perfect information. It seems that the 002 (HDMI) version has not been released in the US. It is not available on Acer's US site, nor do any of the US based online or B&M stores have it.
I'm definitely eager to see how this turns out. I'd love to know what each of the pins definitely is.
One assumes that the HDMI version is only required for the A100 series as the A500 already has full HDMI built in. Would the HDMI circuitry even work with an A500 in the dock? In fact, can you actually use the docks at all mismatched to the Iconia for which they were intended?
zardoz99 said:
One assumes that the HDMI version is only required for the A100 series as the A500 already has full HDMI built in. Would the HDMI circuitry even work with an A500 in the dock? In fact, can you actually use the docks at all mismatched to the Iconia for which they were intended?
Click to expand...
Click to collapse
I wouldn't assume that at all... docs are designed to be left in place... so the purpose for the hdmi on the doc is so that you can keep it connected to your display all the time and not have to worry about plugging in the cable and the power... etc. where the doc satisfies both those needs. And I believe.. the hdmi doc for the a500 was available some time before the a100 was even released. (chk)
loialotter said:
Here are the digikey parts:
PCB connector - $7.67 in singles
Cable connector - $10.67 in singles
Click to expand...
Click to collapse
Thanks loialotter.
What's your confidence that pin 30-35 is actually 12V? Is is obvious (direct connection to the power port on the docking station)?
I will be buying one of those connectors (making a car dock) and want to be sure I won't be frying anything.
I will confirm if the connector fits and works in the A500 once I get the connector.
outsider787 said:
Thanks loialotter.
What's your confidence that pin 30-35 is actually 12V? Is is obvious (direct connection to the power port on the docking station)?
I will be buying one of those connectors (making a car dock) and want to be sure I won't be frying anything.
I will confirm if the connector fits and works in the A500 once I get the connector.
Click to expand...
Click to collapse
It's direct connectivity between +12v on the power jack and pins 30-35 on the zebra cable. These are not the same numbers on the connector itself.
If you look on SJ100278.pdf (digikey has link to drawing) the pin numbers are there. Note that the connector is wider at the top (notches near 21 and 40 on the side guides if that makes sence).
Pin 18,19 and 20 are +12V. There's no block of GND pins like I was expecting, instead GND is connected to 3, 6, 21, 24, 27, 30, and the connector shield. Due to the pattern of the gnd contacts, i'm guessing they're the shielding ones for HDMI. The connector is rated for 1A power per pin which means you need to use at minimum 2 of them.
I still haven't seen anything resembling USB and noticed that the tablet only uses a 20 pin zebra cable to the connector board (power included though they may pass GND through the case).
Now that I have my proper electronics desk at least partly set up, I can look further into the connector.
outsider787 said:
Thanks loialotter.
What's your confidence that pin 30-35 is actually 12V? Is is obvious (direct connection to the power port on the docking station)?
I will be buying one of those connectors (making a car dock) and want to be sure I won't be frying anything.
I will confirm if the connector fits and works in the A500 once I get the connector.
Click to expand...
Click to collapse
It's direct connectivity between +12v on the power jack and pins 30-35 on the zebra cable. These are not the same numbers on the connector itself.
If you look on SJ100278.pdf (digikey has link to drawing) the pin numbers are there. Note that the connector is wider at the top (notches near 21 and 40 on the side guides if that makes sence).
Pin 18,19 and 20 are +12V. There's no block of GND pins like I was expecting, instead GND is connected to 3, 6, 21, 24, 27, 30, and the connector shield. Due to the pattern of the gnd contacts, i'm guessing they're the shielding ones for HDMI. The connector is rated for 1A power per pin which means you need to use at minimum 2 of them.
I still haven't seen anything resembling USB and noticed that the tablet only uses a 20 pin zebra cable to the connector board (power included though they may pass GND through the case).
Now that I have my proper electronics desk at least partly set up, I can look further into the connector.
Every now and then you find things that make you just exclaim WTF at the top of your lungs.
The dock connector board located in the tablet does not appear to have HDMI signals on it. The zebra cable between it and the mainboard has 20 pins. 17-20 are +12V, 12-15 are GND. I'm having troubles doing continuity tests between any of the HDMI signal pairs and the other pins on the internal connector.
Bad news on the USB front, there is no 5V and all the USB pins internal to the tablet float at 0.067V disconnected and I don't see similar levels on any of the pins.
It's looking more and more like the dock was designed for a completely different product. Can someone over where the HDMI capable docks are available check their tablet internals and see if the connector board is any different. Alternatively can someone test one of the HDMI docks to see if it even works with their tablets.
I'm working through the tablet side right now, I'll take some pictures and document my findings in a little bit here.
------- New info:
This is the dock pinout as seen by the tablet (other devices may have different pins connected)
1-10 no connection
11 - unknown - traced to Q9 near IR connector on dock but unable to find past there (2v from tablet)
12 no connection
13 - audio connect of some sort - appears to be connected to left channel (after capacitor) through a 1k resistor
14 - Right audio - decoupled with 100uF
15 - Left audio - decoupled with 100uF like right channel
16 - Audio ground - not connected to main ground
17 no connection
18-20 +12V
21-30 HDMI - NO signals connected except GND at 21,24,27,30
31 - unknown - 3.3v from tablet
32 - TXD pin on 8052 through a level converter
33 - RXD pin on 8052 through a level converter
34 - unknown - 0v - 3.3v when dock unpowered but tablet connected so this may be a dock detection
35 - connected to 33 on tablet side
36 - connected to 32 on tablet side
37-40 no connection
That being said - anyone wana mod their tablets? I was thinking adding a tiny USB hub in where the USB cable runs and make a new dock connector that has USB on it (taking over for the stupid serial pins maybe). Would need a new series of docks (or mod boards for the docks)... maybe a silly idea though
----
Oh, also, is there anyone even interested in me reverse-engineering the serial protocol used for the IR control? I can probably do so with some time but it'll require me to reformat my tablet to factory as none of the other ones seem to support the dock.
:facepalm:. I bet they designed this port, initially, for their own proprietary means in a lab/repair environment, and said "Ya know, if we're gonna have this ugly port on the thing, may as well find something that the consumers would be able to use this for", thus coming up with the dock and only for syncing...
Acer UK store( http://store.acer.com/store/aceremea/en_GB/list/parentCategoryID.55934900/categoryID.56077100 ) claims that the HDMI version of the dock is only for the A100/A101 while the non-HDMI is only for A500/A501.
Power up tablet throught dock port
Anyone knows if it's possible to send a signal to power up (as if you push the power button) to power up the tablet?
I know that they have a powerbutton on the remote but i don't know how to do it to start it.
Thanks!
After many hours of research and hands on work I have finished my in dash install in my MK4 Golf. Stock 5.0.2 with Timur's Kernel, Power Amp and Torque Pro.
First thing I'd like to say, I am HORRIBLE at plastic work. So my finished trim piece is not as clean as I'd like it to be but I had to stop and paint as I was just doing more harm than good. When I have some time I think I'm going to try and fix the trim, I'm going to see if there's someone local that can give me some pointers.
I used ABS cement to bond the trimmed metra kit to the modified trim piece, than I used plastic bumper filler to fill the gaps and finally sand prime and paint... Im a sound/electronic type guy with a small mechanical background.. NOT a body man. Lol
I wanted to make this a permanent install, contrary to the pre made trim pieces I could have bought that would have made the tablet removable. So I decided to mount it behind the trim piece rather than in the front. I also used PL Premium glue to hold the tablet in place.. This stuff is AMAZING.
http://www.lepageproducts.com/ProductDetail.aspx?pid=137
I relocated my Pioneer DEH-80PRS to the glovebox, made a secondary "kill switch" hidden in the ashtray and added 3 USB ports under the main trim piece just above the ashtray. Nice thing is I sourced the interior parts so I still have all the stock pieces in case I sell the car.
OK, so here's what I used:
Nexus 7 2013 (obviously)
OTG charging cable
http://www.amazon.ca/gp/aw/d/B00SMCJ8U6
Metra Double Din kit
http://www.amazon.ca/gp/aw/d/B002U5UD8C
For power I used this step down module
http://m.ebay.ca/itm?itemId=331477762049
Belkin Bluetooth receiver modified to accept power via USB (already owned one)
http://m.belkin.com/us/p/P-F8Z492/
And I also ordered a Bluetooth OBDII
http://www.amazon.ca/gp/aw/d/B009NPAORC
My deck has Bluetooth as well as 2 USB ports and 2 line in 1 rca input and 1 1/4 headphone jack. Now, I wanted to keep the Bluetooth available for my phone (nexus 6) so I used the belkin adaptor to receive the audio via Bluetooth from the tablet, convert it to line out and used a 1/4 jack to rca to input into my deck. The belkin receiver is located behind the tablet.
I then used 1 USB port from my deck to power the belkin and the other with an extension to one of the previously mentioned added ports. The other two are connected to a non powered hub (behind the tablet) and plugged into the OTG cable. From there I can freely plug in my USB sticks with music or movies and can swap them at any time.
I took an unused 12v accessory line from the fuse box ran it to the switch I mounted in place of the lighter (beside the ashtray) and from there to a relay. The relay takes constant power from the existing lighter power supply wires, and feeds the 12v downstep module located under the center console, (plugged into OTG cable of course) now depending on the position of the switch the tablet will turn on with the key, or accessory position of the key like the stereo does. This way if I don't want the tablet to turn on, say, in -30 Celsius I have this option.
Here are a few pictures I took with my nexus 6.