[Nexus 7 (2013) General] Frag Mortuus:
N00b needs hand held, or maybe just guidance.

Warning: This will probably be a long winded post as I want to attempt to explain everything I hope to accomplish in good detail, in hopes of everyone that is willing can understand and give me the best advice.

Hey guys and possibly gals,

I have read this entire thread and am amazed at everyone knowledge about Android, the Nexus 7 hardware, and electronic modifications. I was originally thinking of getting one of those HuiFei Android units for my car, but after reading a couple hundred pages of that thread I decided that the amount of money it takes to buy the unit to only something that I will have to modify in order to meet my expectations and then have no real recourse if the item breaks because the transaction and company are all based out of China. So, I decided to revisit the idea of using a tablet in my car.

Here is my idea and plan. Please excuse my ignorance regarding Android modification and the capabilities of the hardware I think I will be using.

Car: 2010 Mazdaspeed 3 (w/ stock head unit & speakers)

Metra mounting kit (modified to fit the Nexus 7 2013 flush).

Phone: HTC One M8 4.4.3 (stock, no root).

I plan to relocate the head unit to somewhere in my car. Does anyone know if wiring harnesses exist that plug into the factory head unit (FHU) to give plain wires on the head unit side, similar to the way aftermarket head units? The reason I ask is because I don't want to cut my factory wiring, but in order to relocate my FHU I will need to lengthen the cables that plug into the back. I know I can get a harness that plugs into the factory harness that gives bare wires, if I had one a harness that plugged into the FHU I could solder wires the length I need to connect the two harnesses and not disturb the factory wiring. I need to keep the FHU in some capacity to keep the bluetooth in my car working.

What I hope to achieve with this system (some items I have added after reading this whole thread):

1. Replace all functions I currently use my phone for, which includes, Pandora, Google Music, Google Maps, Phone Calls and that's about it.

2. Modify tablet software to allow incoming calls and texts to appear on screen, and hopefully have a dialer that I can use on the tablet screen which will dial a number on my phone, or pull up a contact and have my phone dial the number. Ideally I would like to be able to pick up, hang up, and all other phone functions through the factory head unit and steering wheel controls, but still have the calls and texts etc show up on the screen. Also, if I could still initiate a call or hang up from the tablet that would be amazing.

3. Have tablet go to sleep when ignition is off and wake up when ignition is on. Auto dim the backlight depending on the ambient light, which is probably handled natively through the tablet as-it. Also, resume last application after waking up with ignition.

4. This one I don't know if it's possible. Use the factory steering wheel controls for media control through the tablet and bluetooth for phone.

5. Use OTG connected to USB hub for DAC, power to tablet, connect external HDD (preferably 1TB or higher and no external power, but will use external powered if required), and a backup camera that I can power by the back up lights.

6. Have the backup camera turn on using back up lights and have the app automatically launch.

7. Have a highspeed OBD2 bluetooth adapter plugged into my car and send the information to my tablet for use with Torque.

8. Install wireless charging in the cubby hole in my car where I put my phone.

I think that's all.

To accomplish all of these things I would need to be able to connect my phone to both the tablet and the FHU via bluetooth, then the tablet to the phone and the OBD2 adapter via bluetooth. Also, the phone to the tablet via WiFi, then the other devices to the tablet via USB.

The only thing I'm not sure is possible to use the steering wheel media controls to control the tablet and the steering wheel bluetooth controls to control the phone. Maybe you all have a better, more elegant way to make everything work together.

I know all of these things have been discussed in this thread, but I haven't seen any instructions on the implementation. Would any of you all know of any links that break these tasks down to simple terms and instructions? I love doing things myself and have no problem with learning as long as I have a guide that speaks on my level. I'm an IT professional so I have a good bit of tech knowledge, but when dealing with something new I like to be as thorough as possible to avoid breaking anything that I may not have the money to replace if I break it. Also, I have rooted an old Samsung Boost Mobile phone and installed CM on it, but that was years ago. I also rooted and installed CM on the original Kindle Fire, but again that was a while back. I think things have gotten far more complicated now.

I appreciate any help you all can give.

Edit: Also, when is the difference with the 2012 versus the 2013 in regard to my plan?