ah great, i'm planning on using the galaxy tab 2 as well, did you find the power connector a problem inside? / was there enough space?

There is a problem with fitting the tablet with the usb and headphone plugs, I will be modifying the hood some more today to fix that issue. Unless someone knows where it get a plug that makes a 90* turn right where it plugs in. lol

The modification will only be minor and should be unnoticeable when completed.

could cut up the plug a bit and make it 90 degrees?

I had to cut/shave the charging cable and drill a hole on the side to allow the cable to come out, otherwise it wouldn't fit.

Hook up to ACC and it'll charge when the key is on. Hook up direct to your battery and it'll leave you with a dead car battery one day.

If I power down after a drive home from work and the tab only charges up to 15% in that time, chances are in the morning it'll be shutdown.

Hence why I've been considering an even more sophisticated circuit with a tether pack.

Also something else to consider is sufficient cooling, especially if the tab has a thermal sensor (most do).

On a warm sunny afternoon you will find yourself unable to charge because the thermal sensor has tripped and disabled charging.

Been there done that one too... was a problem in the thick of summer for me.

I leave my tablet charging all the time. The car hasn't been driven in 3 days now and the battery is still good *touch wood* I'm gonna monitor it and see how it goes. I've also left the car in the sun for roughly half a day, although its not summer here yet, the tablet was still ok. But again I need to monitor this as well.

I intend on hooking it up to acc. I don't see keeping it charged as a issue, but heat I'm sure will be. Time will tell.

Give it time.... There are a number of subtle behaviors that'll eventually surface. All manageable, but important to be aware of. I too have considered running my charger direct to the battery but the prospect of coming out to a dead battery when I'm due for a meeting at work, or just wanting to head home has held me back.

Once at 100% these tabs draw very little power... Would like to know more about your experience running direct if things change and/or you encounter some of those subtle behaviors.

if it's connected to acc instead of just the 12v it will only draw power while the key has been turned to acc or you've started the engine, thus you wont be drawing from the battery while the cars off.

Like ShellDude has pointed out the tablet draws very little power when fully charged. It only ever gets warm when the screen is on or under the sun. I've found a issue where the screen turns on when the hood is in the closed position. I'm not quite sure what is waking the screen. I've noticed it only ever turns on when its at home connected to wifi. My guess is some notification is causing a screen wake. This probably is only be an issue with my particular tablet.

I'll try report back with how long I can keep the tablet charging on the car battery. If its any help my particular tablet can stay on standby on its own internal battery for over 3 weeks, thats with wifi and bluetooth and gps enabled.

Luckily, if I do find my tablet draining the car battery too much, I can easily change the charging behaviour in the Arduino code.

We need a good DIY on this including recommended parts list and good step by step with pictures. It's an awesome option I think and would love to try it though I'm sure in the end I would end up with nothing but a broken hood an non functioning factory nav :)

I'm not sure what your point is.

Re sleep time: my streak lasts a couple days from a full charge. It would be interesting to see how it would deal with a long down time hooked up direct.

Without getting too off topic, ShellDude is right. You want your tablet to go into deep sleep to conserve the battery on the tablet, and I am guessing that this app may prevent that from happening. You absolutely could power cycle your tablet every time you let your car sit for a few days, but that negates the purpose of the app. Once the tablets battery is depleted it takes a while for it to charge back up (aka a lot of driving) This is why he brings the tablet inside to charge.

I should mention though that is all depends on what tablet and charger you are using. I have had mine hooked up to the acc line for the last 3 weeks and it still has ~75% charge (deep sleep only it has never been turned off), with very little driving. During the winter though I am sure it will require rebooting.

Well since I have to drive the car 5 days a week minimal, at about 1.5 hours a day... I think I'll be alright.

Reporting back with car battery info:

I left the tablet charging for 3 days without driving the car, result: dead car battery.

I guess touching wood does not help.

Prior to this I was driving the car everyday. I think I'll change the charging behaviour to only charge when ACC is on.

Again with my Streak -- battery life will vary -- I drive 40 minutes in the morning and another 40 minutes in the evening Monday thru Friday and I have to intervene charging wise every week to two weeks.

Sounds like the perfect excuse to make more road trips :)

After switching to charging only when ACC is on I'm experiencing the same issue as ShellDude, I don't drive long enough to fully charge the tablet.

I think I'm gonna put a timer in the code to charge the tablet for max 1 day while the car is off.

I have a new 3g tablet on the way from china (ICS) that will need some modifications (namely relocating its mini USB charge plug) that I plan to revisit this with. Depending on results one of these two tabs willbe iintegrated into my usdm nav tray... although I'll likely not keep it on account of the mobility I get from using the JDM one.

I will have to solve this as part of that setup.

anyone know a good place to grab a "L" shaped or right angle 3.5mm male headphone jack? I've already raided all the radio shacks here, and they are too fat too fit.I can only find the right kind on eBay from China... don't really wanna wait that long

hmmm looks like i'm going to hit this barrier too, damn

Fantastic Work!!!
I learn from this manual to make a similar project!!!!
THANKS from SPAIN!!

Testing the hood
 

Could you explain to me how you tested the nav hood outside the car? Im not that good with electrics.

I wired it up on my work table and used my jumper pack to power it.