# Final stages of planning on Nexus 7 install



## Rich.E.Rich (Jun 16, 2007)

Ok, I am planning a Nexus 7 in-dash install for my GLI. Signal flow is as follows:

Nexus 7 ==> USB hub ==> Fiio E07K DAC ==> 3.5mm to RCA ==> MiniDSP 2x4 ==> 2 pair of RCAs to MB Quart RM 740.5 amp.

I have a few things that are of concern:

1. How do I tap into the vehicle power to provide power to usb hub only while ignition is on?
2. How do I provide a remote turn on lead to the amp?

Rich


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## focused313 (Apr 19, 2012)

1. Find a cig lighter in the car that only works when the ignition is on. Tie into those wires.

2. The remote turn on for the amp can be wired to the same location as #1.


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## Rich.E.Rich (Jun 16, 2007)

focused313 said:


> 1. Find a cig lighter in the car that only works when the ignition is on. Tie into those wires.
> 
> 2. The remote turn on for the amp can be wired to the same location as #1.


Is it ok to have constant 12v power to the remote?


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## basshead (Sep 12, 2008)

Ill have 2 relay triggered by the accessory 12v on mine

One for the DC to DC usb power DCDC-USB, Intelligent DC-DC converter with USB interface
And one for the amps remote

Now i need to find a way to put that nexus in deep sleep when i turn off the power...

OP is you are using the mini dsp you should look into a USB to i2S interface instead of going analogue with the fiio.

EDIT: NVM just found the deep sleep option duh!


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## basshead (Sep 12, 2008)

Look like i won't need relay with the DCDC-USB... we shall see when i get it...

Some FYI (you might already know)

you will need to root your N7 and load a custom ROM (USB ROM for Nexus 7) to be able to have USB sound (and other "car" features). The fixed installation mode will deep sleep the device when you remove the usb power and turn back on when the power is back.

If you want to use an angled usb extension (left or down angled) to plug your OTG cable you will need one that have all 5 wires connected, most don't wire the pin4 making the OTG useless. I've order mine from usbfirewire.com.


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## JayinMI (Oct 18, 2008)

No, you don't want to use a constant 12v source or turn on. The amp would stay on all the time and eventually kill your battery. The last coupe of generations of Jetta/Golf have a switched accessory at the lighter, as stated above.

Jay


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## Rich.E.Rich (Jun 16, 2007)

JayinMI said:


> No, you don't want to use a constant 12v source or turn on. The amp would stay on all the time and eventually kill your battery. The last coupe of generations of Jetta/Golf have a switched accessory at the lighter, as stated above.
> 
> Jay


Sorry for the mixup in my terminology. What I meant by constant is a steady flow (while ignition is on) rather than a one time signal to tell the amp to turn on/off.

I was under the impression that a remote turn on is not a steady current.


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