Nexus 7 Car Audio DIY
 

Ok, so I haven't started this yet because I'm still waiting on parts to ship, but I figured I would lay out my plan. The goal of this is to be cheap and usable. I'm going to keep the stock head unit and build a removable bracket to mount a Nexus 7 in front of it. This allows me to still use the bluetooth (for phone calls) and radio.

To mount the Nexus 7, I'm getting [ame="http://www.amazon.com/gp/product/B008NMCPXW/ref=ox_sc_act_title_1?ie=UTF8&smid=A29LLD0WGS56WE"]this[/ame] case and making a bracket to mount it to out of either aluminum or steel (depends on what my friends have lying around). the bracket will have a hinge so that the tablet can swing out to the right so that I can access the headunit controls without removing the tablet. The bracket will mount to the plastic panel around the headunit with magnets. The USB cable will fit between the headunit and the plastic cover without issues, but will look kind of sloppy when the tablet isn't installed. Unfortunately, I haven't been able to find a way around this, as I cannot find a micro USB extension cable with all five pins usable at each end.

A major downside of the Nexus 7 for projects like this is that the internal DAC is pretty bad, so audio output over the 3.5mm jack sucks. I got around this by using a custom kernel to allow me to use a USB DAC and charge the tablet at the same time using an OTG + USB power Y-cable. Another plus from this setup is that there is only one cable to connect to the tablet.

Here is a simple wiring diagram:

http://i.imgur.com/JUSWj.png

I'll try to keep updating this as I start building the bracket.

In for the bracket as I have a Nexus 7 that I want to use for Maps and Torque.

eentresting..sub'd!

You're going to love torque in the car. I love it on my head unit! :thumbup:

sub'd :respekt:

I would suggest Nexus 7 + Proclip + Tablet Mount. It's what I plan to run Torque Pro on. I've got the clip, but Nexus 7's are on backorder on the Egg so waiting for restock.

I would like to see what you will fabricate though, the proclip w/ car charger for Nexus 7 isn't exactly cheap.

Yeah, I checked out the proclip route, but it's far too expensive for my taste, and I would most likely have to rebuild the USB connector to do what I need.

I mainly want it for codes, boost, IAT's, other temps, oil, etc.

That's what I use it for. Well haven't gotten a code, and don't have boost yet, but I monitor the temps and such of other stuff. Love having gauge widgets on the head units home screen too.

I will be switching to a USB DAC but only when I swap out the OEM speakers.

The custom bezel work is $400 almost the entire cost of installing the tablet.
For me that was the most annoying part.

So far using the tablet full time now and no major issues to report.
I would love to see someone actually do a full Android head unit using modern hardware and display technologies and latest versions of Android.

As it is since installing the Nexus 7 there have been 3 major version updates.

I'm actually considering doing a kickstarter and making a market competitive head unit. I just need to find an electronics engineer and a CAD person to design the actual unit. Then I can price out manufacturing cost and open up pre-orders.

But if they can make a 200$ quad core tablet, then I can't imagine the cost of a decent DAC with amp, FM radio, and chassis would cost much.

If you could basically do Nexus 7 Level hardware into a head unit, with the control ability of the Android head units you tested and video switching and get it done for under $650 or even $700 you would have a serious product on your hands.

We both know the main reason the tablet is $250 is because its heavily subsidized by Google. But a very good single DIN head unit is only $250, you can pack a quality AMP, DAC I dont see how you could not put something together for $600 and tack on $100 profit for each.

Right. But I mean even those hdmi sticks with dual cores and 512 ram running ICS are only 80 bux. I don't see any reason why it can't all work nicely. I need an engineer to map it out and such.

Thanks for making so much headway with trying to make a permanent install. That's my long term goal too, but I'm kind of impatient, so this is my way around all the expensive stuff lol. Did you write the app you used? If so, I'd love to talk to you about it. I have a design very much panned out, but its been a while since I've done any coding in general, let alone android. I haven't made anything since I had my G1 ha! Have you tinkered with a bluetooth OBDII reader? Do you know of any available maps api that has speed limits? I'm trying to make a torque competitor with a much cleaner ui.

def keeping an eye on this thread :D

Alright, so update. I have been tinkering on and off with this, and I've changed how I'm going to do it. So far, using an external DAC is not reliable. If you lose power to the tablet, it's a huge pain to get it working again. This leaves me with 3 options: 1) use the head unit's bluetooth for the tablet and sacrifice bluetooth calling. 2) use the bluetooth on the tablet hooked up to a bluetooth to 3.5mm adapter thats plugged into the aux port on the head unit. 3) Use the internal DAC and hook it up using a 3.5mm cable and forget all the fancy one-cable shit.

I think I'm going to go with number 3. I would rather not sacrifice bluetooth calling, and I haven't seen one bluetooth to 3.5'' adapter that has great reviews. Also, a new product factors into the equation: http://www.excaliberpc.com/622650/as...g-station.html

http://cdn-static.cnet.co.uk/i/c/blg...xus-7-dock.jpg

This dock should be available within a week or so. While it is slightly expensive, it uses the pogo pins on the Nexus 7 to connect to it. This means I can take it apart and use it to build a car mount so that the nexus 7 is removable, but I don't have to plug in or unplug any cables. I'll put out another update when I get one and have it apart.

Thanks for looking into this... I wish that they just made a unit that would allow me to slide my Nexus 7 in and out. I'd just connect it to my phone for data and stream whatever I wanted over it and take it out for work etc. It wouldn't be hard with those pogo pins! The Subaru head unit SUCKS.

Have you seen this thread?

http://rootzwiki.com/topic/37755-tim.../page__st__230

Progress on USB DAC use it seems

Yeah, I watched it for a while. Look back a couple pages, you'll see my posts ;). I still may go this route if the kernel is solid, but I really like the pogo dock as a quick release solution, and it doesn't allow for the DAC use.

Hows this comming? I want to add the nexus 7 to my FRS but i need a better D.I.Y or at least a list of everything needed to buy ect.

I'll make the D.I.Y once i complete it

I'm still waiting on the dock to come in stock. They're hard to come by.

Please read this very good thread on LS1Tech

http://ls1tech.com/forums/stereo-ele...h-install.html

so your going to use the dock as a hub to avoid the dac?

wont the dock block it from being mounted inside the panel?

My goal was never to mount the Nexus 7 inside the panel. I planned to make the tablet removable and retain the ability to use the sock stereo for bluetooth, HD radio, and CDs.

Maybe you guys can help me... and if i can do it with little help i'll make a D.I.Y

so nexus 7 in dash

Goal: replace in dash headunit, nav, hand free calling, music streaming from phone, fm radio or pandora

questions:
-nexus 7 doesn't have fm so how can we get it or comparable?
-keeping the stock speakers how does the 3.5mm port hookup to dispense sound?
-how does the hands free stuff work? just using an app?
-what are the drawback of using the nexus 7? turn on tethering everytime you are in car?

Maybe you guys can help me... and if i can do it with little help i'll make a D.I.Y

so nexus 7 in dash

Goal: replace in dash headunit, nav, hand free calling, music streaming from phone, fm radio or pandora

questions:
-nexus 7 doesn't have fm so how can we get it or comparable?
-keeping the stock speakers how does the 3.5mm port hookup to dispense sound?
-how does the hands free stuff work? just using an app?
-what are the drawback of using the nexus 7? turn on tethering everytime you are in car?

What USB DAC's have you been trying Dezoris?

TuneIn Radio app can be used to tune into MANY radio stations across the US and world.

Finding a way to get an AUX cable to go into the factory amp would be best.

Google has VERY good voice recognition software.

The only drawbacks I can think of would be having to turn on tethering to get data on the tablet; and that you can't use the physical buttons on the side to adjust volume, and turn on/off the screen/tablet.

But I'm sure there is an app for a widget to adjust volume from the home screen, and most music apps have volume adjustments in the app itself.

Also, there are apps to allow you to reboot the tablet, etc.
I would NEVER recommend shutting the tablet completely off or turning off the screen because you can't access the power button.

I know there have been some custom ROMs that will allow you to swipe the screen when it is locked and off to turn the screen back on. But you would have to root and mod it to do that. I would just recommend turning on the option to NEVER sleep when plugged into a charger, which I believe is in the developer menu.

If you keep the stock software that it came with then you can update it easily without issues of worrying about removing the tablet from the car. It's just a few simple touches, and a reboot, then you have the latest update.

Finally got my dock and started to modify the shape to make it fit better.

http://i.imgur.com/BIuw4fi.jpg

http://i.imgur.com/FmHtpMX.jpg

http://i.imgur.com/3dBbOAJ.jpg

http://i.imgur.com/U2iCZbj.jpg

http://i.imgur.com/uvH2Nfg.jpg

in for the final results.

Why not try pairing just the audio with the nexus 7 and phone separately. Go to settings on your nexus, Bluetooth, click the gear next to car multimedia and make sure it only shows media checked. Do the same on your phone and ensure only phone is checked. Undo whenever you want to play media using your phone. This method works well, I can use my phone to play songs from my phone in my gf's car while her phone is connected to the car. When someone calls her it rings through the car and when someone calls me it comes out through the phone.

Sent from my SPH-D710 using Tapatalk 2

That's not a bad idea, and previously, I may have been up for it. I ran into a bandwidth issue with bluetooth, however. I am using Torque with a PLX Kiwi, and if I set the refresh time to fast, there is not enough bandwidth to transmit audio as well. I will be using bluetooth in my tablet for Torque, and bluetooth in my phone for calls.

Update:
I am waiting for Sugru that I ordered to ship. When it does, I can start the final install.