Thanks!
Quote:
Originally Posted by dreamonn
Couple of questions:
Is there anything that you would do differently if you did it again?
Do you have any other plans to extend the functionality?
Are there any issues with using a Nexus 7 in a car install that still need ironing out?
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There ARE a few issues, to the degree that I've temporarily given up on using this (my phone is easier and better still, for now).
The biggest problem is power. It happens to be the case that the USB cable I have supplying the N7 is relatively poor quality and high resistance, and the N7 throttles back how quickly it charges as a result. Unfortunately, the outcome is that the N7 won't charge under heavy use (GPS and screen, which is obviously prime functionality), and it'll charge only slowly with the screen off. That's a dealbreaker, but could be fixed with a new, better cable.
The bigger problem is power TIMING: I've got the cigarette lighter sockets wired to Terminal 30g (rather than T15), so they come on when the car is woken up from sleep (generally, powered from unlock to 30m after lock). Unfortunately, that means the 3G dongle powers off until the car is unlocked. On the one hand, this is good: it consumes a bunch of power, the battery would be drained and unable to start the car in a matter of days. Probably relatively many days, but it'd be a danger if you left on a long trip. Maybe a shorter trip, too. On the other hand, it means the dongle powers on at unlock. It takes a solid 15-20 seconds to get a connection and for the tablet to get online with it. It may not seem like long, but when you want to hop in the car, put on your pandora or find your directions, then get driving, you can do all of those things on your phone much quicker. Pulling it out and plugging it in becomes the much faster option.
Another power problem, the tablet is set to not sleep. That way, when you're using GPS or music or whatnot while driving, you don't have to use up concentration unlocking the tablet. Unfortunately, that also means it'll eat up 30m worth of battery after you lock and leave the car, only to advertise "HEY I'M A DESIRABLE GADGET AND EASY TO STEAL!" I planned to fix that with a relay PCB that would cut power to the tablet (but not the rest of the devices on the USB hub) as soon as you lock the car and leave. I was planning to do that by using the headunit's amplifier remote line as a signal, but it turns out that doesn't closely follow whether the headunit is on or not (for example, the headunit may be 'off', but the remote line still on for a few minutes), so it may or may not be good enough.
Finally, buttons. The steering wheel buttons obviously don't work for the tablet. I could get the device I mentioned to make skip forward and backward work. I could also probably assign the 'talk' button to play/pause. But then that'd require either disabling stock functionality of all other buttons, or coming up with a more clever device myself that plays man-in-the-middle for button presses, forwarding the ones I want and blocking the ones I don't want. More work.
Bottom line, I will probably revisit this, but for the $20 a month the freedompop subscription was costing me, it's easier and more convenient for now to simply use my phone
