B6 & B7 Android Google Nexus 7 2013 Tablet Install Guide

[BARRY]

Hey guys,
I spent a lot of time trying to find a concise guide, but was always left shorthanded due to lack of information. So after lots of research, I have determined that I will need to write one of my own. Through trial and error I've successfully been able to integrate my an Android tablet into my deck as a full functioning head unit. Below I will list the components I used. I also removed the factory battery and hardwired this to battery+ through way of USB. You'll need to build the external volume control knob. Its fairly easy, but takes some trial and error. You'll need to install software to load the code onto the board. Once that has been completed it should be plug and play.

If you plan to hardwire the tablet to your car's battery, please make sure you do NOT use a USB adapter that outputs more than 2.1a. 1.0amp's is not enough to power the device and anything more than 2.1a will fry your tablet mainboard. I have wired in 2 cigarette lighter inputs. One using a tap-a-fuse to the factory fuse box for a 12v+, and the other to the 12v SWITCHED radio wire.

This guide should work for all other vehicles for the most part. I have successfully done an install to my brothers Subaru BRZ, with adaption to his Rockford Fosgate 360.3 DSP.

Things to Note:

• You'll need to apply switched usb power to the usb hub
• The hub will be plugged into the OTG Y Cable which will power it
• The USB HUB will need to support external power. Some work IF you apply power to one open port
• You will need to apply power to the USB HUB or your devices will state they do not have enough power
• The OTG Y Cable will also need to be plugged into switched usb power. Likely USB adapter to cigarette socket
• You'll need to update your tablet operating system and kernel to support functionality
• You'll need tasker to trigger power on and power off functions

References and Components:
Setting up ADAFRUIT Trinket as volume control knob:

• https://learn.adafruit.com/trinket-u...-knob/overview
• https://learn.adafruit.com/introduci...th-arduino-ide

Android OS/ROM/Kernel:
PureNexus ROM 6.0.1 Marshmallow:

• https://forum.xda-developers.com/nex...ayers-t3190370

ElementalX 5.16 OTG Support Kernel:

• https://forum.xda-developers.com/sho....php?t=2389022
• https://elementalx.org/devices/nexus-7-2013/

Android Installed Software:

• Tasker - https://play.google.com/store/apps/d....taskerm&hl=en
• Nova Launcher - https://play.google.com/store/apps/d...launcher&hl=en
• TOMTOM - https://play.google.com/store/apps/d...y.navapp&hl=en
• Pandora - https://play.google.com/store/apps/d....android&hl=en
• Secure Settings - https://play.google.com/store/apps/d...s.plugin&hl=en
• KLWP Live Wallpaper Maker - https://play.google.com/store/apps/d...allpaper&hl=en
• Phonograph - https://play.google.com/store/apps/d...amophone&hl=en
• WAZE - https://play.google.com/store/search...e&c=apps&hl=en
• Google Maps - https://play.google.com/store/apps/d...pps.maps&hl=en
• Wavesink Plus DAB+ FM-RDS - https://play.google.com/store/apps/d...sinkplus&hl=en

RADIO INTERFACE: PAC C2R-AUDI Radio Replacement Interface with Navigation Outputs for Select 2005-Up Audi Automobiles

• $68.12 - https://www.amazon.com/gp/product/B003E3KRDU
• $59.99 - Alternative - Enfig SRWH-AUD2-B - http://enfigcarstereo.com/ENFIG_SRWH_AU2.html

TABLET: Asus Google Nexus 7 16GB Tablet (Gen 2), 7 Inches (Certified Refurbished)

• $126.85 - https://www.amazon.com/gp/product/B018URWWLE/

DAC(Digital Audio Converter): Behringer uca202/uca222

• $29.99 - UCA-222 - https://www.amazon.com/gp/product/B0023BYDHK/
• $29.99 - UCA-202 - https://www.amazon.com/gp/product/B000KW2YEI/

OTG Cable: 90 degree Y split OTG cable - 90 degree / right angle / left angle

• $1.58 - eBay
• $6.99 - Micro USB Male To USB Female Host OTG Cable + USB Power Cable Y Splitter - https://www.amazon.com/gp/product/B00NSBVNCM/

GROUND LOOP ISOLATOR: rolls HE18 Hum Eliminator

• $45.00 + $6.95 shipping - https://www.amazon.com/gp/product/B004E4LU0W/
• $7.13 - Cheaper Alternative - PAC SNI-1 Noise Isolator - https://www.amazon.com/gp/product/B000K50HJE/

BLUETOOTH PHONE ADAPTER: SoundBot SB360 Bluetooth 4.0 Car Kit Hands-Free Wireless Talking & Music Streaming Dongle

• $19.95 - https://www.amazon.com/gp/product/B00RH29CJO/

GROUND LOOP ISOLATOR AUX: AUKEY Ground Loop Noise Isolator for Car Stereo Systems and Home Audio Systems, 3.5mm Audio Cable Included

• $9.99 - https://www.amazon.com/gp/product/B01L1NP7YI/

FM RADIO ADAPTER: eBay, your choice of RTL2832U chipset units

• $7.30 - eBay
• $23.95 - NooElec NESDR RTL-SDR & ADS-B USB Receiver RTL2832U & R820T2 - https://www.amazon.com/gp/product/B00VZ1AWQA/
• $20.95 - RTL-SDR Blog R820T2 RTL2832U 1PPM TCXO SMA Software Defined Radio (Dongle Only) - https://www.amazon.com/gp/product/B0129EBDS2/

VOLUME CONTROL INTERFACE BOARD: Adafruit Trinket - Mini Microcontroller - 3.3V Logic, I'm sure the 5v unit would work as well. It is part number 1501 instead of 1500

• $6.95 - https://www.adafruit.com/product/1500
• $5.42 - https://www.arrow.com/en/products/15...uit-industries

VOLUME CONTROL KNOB: Bourns Optical Encoder Rotary, a rotary encoder will not have a start and stop like a potentiometer

• $3.85 - https://www.arrow.com/en/products/pe...s-s1024/bourns

EXTERNAL VOLUME CONTROL KNOB: Uxcell Potentiometer Control Knob (5 Piece)

• $6.23 - https://www.amazon.com/gp/product/B00EZK4C1O/

RCA TO AUX CABLE: Monoprice 6inch Premium 3.5mm Stereo Female to 2RCA Male 22AWG Cable (Gold Plated) - Black (2 Pack)

• $11.90 - https://www.amazon.com/gp/product/B01K276GIU/

RCA AUDIO CABLE: Bonayuanda 3 RCA Male Jack to 6 RCA Female Plug Splitter Audio Video Av Adapter Cable 12inc

• $6.69 - https://www.amazon.com/gp/product/B01J007XGO/

RADIO FACEPLATE: Enfig RMK8-A4B67

• $49.99 - http://enfigcarstereo.com/ENFIG_RMK8_A4B67.html

USB HUB: TBD, eBay one I purchased died, and not all USB hubs support external power input (if not you can use one of the USB ports as a power input from cigarette USB adapter)

• $12.99 - eBay Generic Hub that accepts external Power (failed on me, but worked flawlessly until failure)
  
  
  Currently using this unit, which works, but my volume control knob does not seem to work with it:
  7-Port USB Hub with on/off Switch, Black
• https://www.amazon.com/HDE-SuperSpee...dp/B00L5IS9KE/
  
  Also tried this unit but, volume control doesn't seem to work as well unless physically hot plugged:
• $11.99 - Cateck Premium 7-Port Aluminum USB Hub with 2-Foot Shielded Powered Y-Cable - https://www.amazon.com/gp/product/B00VH5KO4Y

CIGARETTE OUTLETS: eBay or Amazon

• $0.79 - eBay
• $6.19 - uxcell Car Charger Power Cigarette Lighter Female Socket Black w 26cm Cable- https://www.amazon.com/gp/product/B00EZJBELQ/
• $9.88 - Ambuker DC 12V/24V Dual Cigarette Lighter Plug Socket - https://www.amazon.com/gp/product/B07116RNCV/

CIGARETTE USB ADAPTERS (you'll need 2, bluetooth adapter comes with 1): RAVPower Quick Charge 3.0 54W 4-Port Car Charger

• $9.74 - https://www.amazon.com/gp/product/B01LCFEQM4

DOUBLE SIDED TAPE: 1 Roll 0.6cm Car Double Sided Adhesive Strong Adhesion Sticky Foam Tape House 3M

• https://www.amazon.com/gp/product/B01G3JGBK4/

[BARRY]

Photos and Videos:




















VIPER4Android Audio DSP and Equalizer:

[BARRY]

reserved. to add...

ANDROID SETTINGS:
.

TASKER PROFILE CONFIGURATION:
.

[MetalMan]

Nice writeup! Have only skimmed through parts of it so far but it looks quite detailed.

My B5 has a N7 2013 as the head unit as well. I previously used a Behringer UCA-222 (or was it 202) DAC with my N7 2012, but then that tablet completely died...
On my N7 2013, it will not output stereo audio with the Behringer DAC (only outputs audio as mono). I ended up with a HiFiMeDIY Sabre DAC (2016 model, UAE23) that works great in stereo and is moderately inexpensive and compact.

With the Behringer DAC it was nice to plug the BT phone adapter to the input, which of course gives BT phone audio through the audio output. I still haven't reincorporated the BT phone audio and it's been almost a year...

BTW I'm using Timur's Kernel (used USB ROM from Timur on N7 2012) and it's working great.

I don't see the volume control detailed on your schematic/diagram. Is this incorporated as a USB volume controller for Android? I went a little different route and bought a (cheap but good) line-level volume control that goes between tablet and equalizer (my equalizer directly outputs to the amplifiers).

Last thing... ground loop isolators are somewhat of a band-aid based on the research I did back when I had noise issues. They can diminish frequency response. For me, my ground loop issue was totally resolved when I bypassed the Bose signal wires completely by running my own amplifier signal wires. Granted this was a B5, and I'm not using the Bose amplifier.

[BARRY]

The USB Volume Control emulates the keyboard volume buttons which in turn directly updates the volume of android os.

Originally I wanted to bypass the bose setup, but after much contemplation realized it'll work just the same with it. Ground loops do alter sound a bit, the PAC Ground Loop isolator added treble whereas the rolls buzzoff which is a professional audio device added a warm tone. overall i'm happy with the outcome. when i get bored i'm probably going to install VIPER4ANDROID or VIPER4ARISE to allow for on the fly equalizer changes.

With my brothers BRZ we simply used the OPTICAL line out into the Rockford Fosgate 360.3 for a pure digital sound. We were also able to phase correct and tune his alpine speakers. Essentially professional grade quality output at that point.

[Charles.waite]

This is awesome. Subscribed.

I'm soon going to attempt to add in a Raspberry Pi based Airplay as an Aux in. Got all the stuff to do it, but just don't have the time. Also I need to learn how to solder so I can add in a pinheader (Zeros come naked) for a 3.5mm Line-Out hat. Mine is just a (relatively) dumb box that acts as an AirPlay target but will probably just utilize the Aux in capabilities of the RNS-E.I plan on using the MoodeAudio OS but its got Airplay issues right now...

[BARRY]

have you looked into a aux cable bluetooth dongle? similar to what i have with my setup? they're like 20 bucks and work flawlessly. they also have noise cancelling which works wonders. anybody who i've spoken through the device said they heard me loud and clear. it did not sound tiney or airy like you do when you're on speaker phone. a Raspberry Pi hands down is cheaper, but dealing with something that works from the get go also deserves its weight in gold.

[Christian@enfig]

Thanks for including us in this. Let me chime a few things.

If you go with ours I recommend getting a PNP-UNI to connect to our SRWH to make the installation a little cleaner.
http://enfigcarstereo.com/ENFIG_PNP_UNI.html

If you have steering wheel controls. you can somehow use this http://www.rcjoycon.com/ with our SWCL.
http://enfigcarstereo.com/ENFIG_SWCL_UNI.html

Also if you do not need the the cage this is a single din cheaper kit.
http://enfigcarstereo.com/ENFIG_RMK4_A4B67.html

[BARRY]

added video of integration of VIPER4Android Audio DSP and Equalizer. this addition really brings the audio quality to life. if anybody is local and wants to hear the drastic audio quality change feel free to PM me. Subwoofer and speakers sound like high end units now. Clarity and separation is pretty unreal for factory speakers. I always knew the factory BOSE speakers had it in them to produce quality audio. Some songs cause the whole car to thump and vibrate with each bass hit. It's pretty awesome. The DSP does a great job in creating enough separation to not over power the speakers and cause any bleed or frequency crisscross. I'm more than satisfied after installing VIPER4Android, I'm ecstatic!

[naiku]

Nice write up. Not sure how I missed it when you first posted, been running a 2012 Nexus for a few years now and may one day swap it out for a 2013.

[BARRY]

The 2013 model is better...but honestly I'd wait until another highly modifiable tablet with a very bright screen is available. In my E63 I use a 2015/2016 model nVidia Sheild Tablet. Works well enough. The screen is brighter, sharper, and wider than the Nexus 7 2013. It is not a hardwire though. I wished my Nexus 7 2013 was double the brightness. That's the only thing that is lacking for the most part. More than 16gb internal storage would be great as well, as well as the ability to use a newer version of Android as Nougat was twice as fast, but support was lacking.

Those new Amazon tablets are priced well, but I'm not entirely sure how modable they are.

[naiku]

Those reasons are one of the main points I have not swapped out for something newer. Sure, Android 4.0 and the tablet are getting on, but there are not that many tablets out there that are as simply modified as the Nexus and almost a drop in fitment as well. Interesting you wish yours was brighter, I have never had any complaints about the brightness and at night it can be too bright. 16Gb storage does not bother me, I just have a handful of apps and everything else on a USB flash drive.

[BARRY]

brightness is only a concern in direct sunlight or when i have my sunglasses on. i had hopes that Google was going to release their 7 or 8 inch tablet but that got axed. ideally you want a tablet that you can root so you can use tasker to root kill apps before sleeping. some apps hang out using resources and can and will kill your battery within 2 hours if you don't hard wire your tablet to car 12v

[Ma6A6]

Hello Barry!!!

First of all I want to thank you for your B6 & B7 Android Google Nexus 7 2013 Tablet Install Guide, I’m working on this right now.

I’m no expert in this but want to give it a try and have a tablet as head Unit and keep the rest of the Bose system but I have a few questions that hopefully you can help me with…. here I go:

1. RADIO INTERFACE. Whats the function of this? is it possible to use only the cable adapter (without the interface)??

2. DAC. Is the audio from the tablet sent using the USB port in it?? Does this works as a mixer to receive all the inputs (BT, FM, TAB) and send them to the stock amp?

3. If #2 is true, is that the reason we need a Volume control interface??

4. I have read that there is an issue with signal level and/or ground sent to the stock amp. Does DAC solve this issue?? or does the radio interface do it??

I really appreciate any help and thank you in advance. (sorry for my bad english)

Best regards.

Mauricio

[BARRY]

Hello Barry!!!

First of all I want to thank you for your B6 & B7 Android Google Nexus 7 2013 Tablet Install Guide, I’m working on this right now.

I’m no expert in this but want to give it a try and have a tablet as head Unit and keep the rest of the Bose system but I have a few questions that hopefully you can help me with…. here I go:

1. RADIO INTERFACE. Whats the function of this? is it possible to use only the cable adapter (without the interface)??
The radio interface will provide power on signal, convert audio signals, and allow you to utilize things like reverse switch and ebrake signal.

2. DAC. Is the audio from the tablet sent using the USB port in it?? Does this works as a mixer to receive all the inputs (BT, FM, TAB) and send them to the stock amp?
The DAC converts the digital signal to analog signal for output to speakers.

3. If #2 is true, is that the reason we need a Volume control interface??
Volume control can be managed through external USB dongle or through use of volume control widget through Android. I originally used "Fusion Control USB Powered and Controlled Rotary Volume Knob" which I purchased through amazon. This device worked flawlessly, but I cut through the circuit board which damaged the unit. Since then it would seem the company is no longer in existence. The volume knob I built seems to only work upon fresh boot up and does not seem to come back alive after resume from sleep. I now simply use a volume control android app/widget.

4. I have read that there is an issue with signal level and/or ground sent to the stock amp. Does DAC solve this issue?? or does the radio interface do it??
If you follow my build guide this should accurately guide you for any BOSE equipped vehicle. You'll need a different set of Audio Converters from enfig if your vehicle does not come with a BOSE system.

I really appreciate any help and thank you in advance. (sorry for my bad english)

Best regards.

Mauricio

Since first write up, there has been an onslaught of new Android single and double DIN head units with varying screen sizes. It maybe more cost effective and easier just to go that route. AliExpress, Amazon, and eBay will be a good source for those. I would search YouTube for reviews as there have been a few recently posted.

[Ma6A6]

OK, Thanks!