In-dash Install - My Setup and Need Info/Advice - Nexus 7 Q&A, Help & Troubleshooting

So, I have had my Nexus 7 installed in my 2007 Toyota Tacoma for 7 months. I use the Behringer UCA202 DAC($20). I am a cheapo so I preferred $20 over the $76 Fiio E10K that is supposed to be better. I also like that I have a mic input that works on the UCA202. Makes voice search and phone calls possible. Grounded the outside of the rcas to the chassis to help with the electrical noise. Used Premium Monoprice RCA cable to also help with the electrical noise. ($7) Using Alpine KTP-445U($114) to amplify the tablet audio output to the speakers. (Rockford P1675-S in the front and P1675 in the rear, $200) I needed my steering wheel controls to work so I used the Joycon EXR Steering Wheel Interface ($58). Its setup took a couple hours but after I completed the setup I have had ZERO issues with it, LOVE IT! Please note that the Joycon EXR will only work for analog steering wheel controls. You would need the EXC($92) for CAN, IBUS, resistive, and digital steering wheel controls. Used a cheap usb otg charging adapter for allowing usb otg while charging. Be careful with these some cords will allow this, some will not. Pay attention to reviews to get some insight but even then it's a shot in the dark. You also need to make sure that it is a high quality cable so that the wire gauge can handle the current for fast charging. RTL2832U DVB dongle for being able to receive FM stations on the tablet. Also used a cheap 4 port usb hub. Used three of the ports for DAC, EXR, DVB.
Okay, all done with my setup. Now on to getting some advice. I used to use Timurs Kernel for 5.1, cost me $20. It worked okay but it would often freeze when I shut off my truck so the tablet would then reboot after 20ish seconds. 3 months after I bought LP Timur came out with MM. But, he wanted me to pay for that one as well. Hell no. I emailed him, he wouldn't upgrade me without paying. Didn't want to pay for his kernel in the first place so there was no way I was going to pay for it again. So... I decided to take on the setup of the tablet for Fixed install on my own. I installed Cyanogen Mod (13.0-20160827-NIGHTLY) with the Elemental X kernel version 3.16 (last reported version to include working usb otg + fastcharging) Well I get charging + usb otg but its not fast charging. No big deal, I can deal with that for now.
The problem I am having is that I cannot for the life of me figure out how timurs kernel would only lose 1% of batterylife in 12 hours when the truck was turned off. I have tried multiple things, done a ton of research and nothing seems to get close to 1% for 12hrs. The best solution I have found is using the apps Greenify, No Wakelock, and Force Doze as well as disabling Google Sync completely. This has gotten me down to about 8% for 12 hours. When I previously used Tasker as the overall solution I was losing 12% for 12 hours. (disable WiFi and location, enable airplane mode, enable battery saver)
Anyone have any tips to improve the drain while my truck is off?

Related

Incredible car project

I've had my Incredible for a month or two now, and rooted it the day I picked it up. I've dug all over this forum learning the ins and outs of this phone, and figured I'd finally give something back.
Car audio has always been a big hobby of mine, and I actually competed in sound quality a couple of years back. So, while researching the Incredible, as soon as I discovered the tv-out cable, my first thought was to feed it into my car. I was very proud of myself thinking I was the first person to come up with this...until I started searching, and realized I wasn't. At all.
Either way, it was hard finding info on this solution because google pulls nothing but details about the cable, and very little on the solution, so I figured I'd put what I've got here.
I have a 2005 Honda Accord with the factory 6 disc changer in the dash. The dual zone climate controls are integrated into the factory radio, so if you remove it, you lose that functionality (which I didn't want to do). There is a large storage pocket that is removable underneath the radio that allows for an aftermarket head unit, and lower dash kits are available for doing that.
I've gotten out of competition, and just have the factory deck now, but wanted a way to play music from any phone I had. PAC makes auxiliary input adapters that integrate with factory radios for just about any car. I bought one for my car, installed it, and can now plug in anything via 3.5mm headphone jack or by RCA.
When I got the phone, my first idea was a car dock where I could plug in the headphone jack and then charge it, but I hated the idea of having to deal with two cables every time. I had started off using CM7, liked it, but read people complaining about no tv-out functionality, which I could care less about, but the option being available meant that audio going out would be no problem, and since the cable has another input for charging, I could have a one plug solution, and so the project began.
I flashed my phone to SR4.0 to have the tv-out capability, (and love the ROM. I like a lot of the more sense based layouts)
First, the cable. The phone only recognizes tv-out when the video input is connected. This posed a problem for me, as I only needed audio. If the solution has been posted before, I couldn't find it, but if you take a female rca jack, or use a male rca jack with a coupler, and short the signal and ground wires together, the phone goes into tv-out mode and will send audio. I had a cheap pair of radio shack rca's laying around, and cut one end off to test this, and it worked flawlessly. In car audio, they're called muting plugs, and are used to troubleshoot engine noise issues.
Second, the charger. I didn't want to use my car charger port, so after some light research to make sure I wasn't missing anything, I confirmed you can take a car charger apart, solder a ground wire to the wire connected to the metal that sticks out of the side of the charger, and solder a power wire to the part going to the tip. On the charger I used, a fuse was inline, and if you want to retain that, you can use a large zip tie and heatshrink to retain it. I didn't b/c the charger was cheap, and if something was to ever short, it'd burn that out first. Regardless, solder leads to power and ground, and then tap into the wiring going into your factory accessory outlet (or cigarette lighter). Use a test light or multimeter to determine power from ground.
Third, the dock. Google sucks at finding good horizontal docking solutions. My first idea was to buy a horizontal cradle and fab it into the lower dash kit, but that's a lot of cutting, as well as having to remove the usb plug on the dock (because it's not extUSB), and really at the end of the day, you just need an L shaped piece of plastic with a hole cut out where the usb is. I was looking at Droid X docks with my friend, and noticed there are a lot of swivel mount car docks for that phone, and thought that'd be a lot easier to do. Further searching led me to proclip.com where they have docks for about any mobile device. *I tried posting a link, but spam got me* I found them while searching for docks thanks to someone on an ATV forum linking the site. It seems people are using their droids for navigation while going off-roading, and use these docks to keep them anchored.
On the quick search at the bottom of the main page, check the box saying you already have a mount, then under holders, select HTC Incredible to pull up the docks. I purchased 511147, holder with tilt swivel, and received it two days after ordering. It's very rugged, and the swivel seems well built. The mount on the right provides room to comfortably plug in a charger or cable, and I'm going to fab a piece to attach the tv-out cable and charger, and route the wire behind it and through the kit. The dock will be attached to the lower dash kit, and a little ABS plastic, epoxy putty, and paint will smooth over any seams. The other nice thing about this for me is the lower dash kit has a cutout for an aftermarket radio, and a spare pocket underneath. Using the dock, I still have full use of the pocket.
If you don't want to do this much custom fabrication, you can use one of their solutions. On the main page, select your car make and model, and they will provide you with the mounts they have. Their mounts attach to the car without screws or tape, and then from there you select your dock, which attaches to the mount.
Sorry this is long and somewhat rambly, but I've seen a lot of posts and questions asking about this kind of solution, with no clear definitive answer. I drove to work this morning listening to pandora via the tv out cable on my factory radio, with the phone being charged and zero problems.
Another side note, there is an adapter for the HTC Hero that is an extUSB plug that goes into a piece that has extUSB input, power input, and 3.5mm out. It's a lot more ideal for this solution, but doesn't work. The extUSB plug is shaped differently, and the pinouts are laid out differently in the plug. If someone was good at soldering, it'd make an even cleaner solution, as you could rout the adapter behind the dash and plug everything into it.
If someone was interested in swapping the ends on that adapter with one that'd fit the Incredible, I'd be willing to pay for it, just for the lower profile and aesthetics of what I'm doing.
I'll update this with pictures once I get it all installed. Hopefully this is helpful, and I didn't just waste a bunch of time typing what was in another post that I've been unable to find.
Thanks for wasting 5 minutes of my life. Just kidding. Thanks for the write up. Can't wait to see pictures.
Sent from my ADR6300 using XDA App
I was going to wait and reply later, But I have been reading up on this subject, There are a lot of people using pads and removing there radios. So to see a phone doing this hope the pics are good
It'll be next week before I can get any up, headed out of town for the weekend tomorrow, but will grab pics of what I have now and will show the install progress as I go.
Hopefully I can get to 11 posts between now and then so I can throw up pics and links to what's going on.

My Nexus 7 Car Audio Dash Install

I have completed my nexus 7 install as my head unit in my 92 Dodge Diesel D350. These trucks have a din and a half radio in the lower portion of the dash, its hard to get to and see, fold out screens hit the "step" that is just above the radio position and once they are motored out, they end up in front of the AC controls. It just isnt a good option. Also since any in dash unit that compares feature wise to a Nexus 7 (besides audio output) would run about 800-1400 in price and would be to deep for the location I had in mind, it makes the tablet a no brainer.
I considered the Galaxy Tab 7 and tab 2 7.0 because of there HDMI output via dock but I just don't think I will be putting another screen in this truck so I opted for the better hardware at the same price as a used tab that would still work with AT&t.
One of my main goals was not to loose any of the functionality that I currently have in my set up. This includes, bluetooth hands free calling, and the basic automation that a true in dash has(i.e. on and auto play with key on and off and auto pause with key off) On top of that I was to gain google maps and internet connectivity along with android apps. In order to accomplish this goal, a combination of hardware and apps were used.
The hardware used includes a ar Charger 5V 2A charged bought on amazon that I hacked and wired in direct on an ignition source and a parrot MKI9000 that I use as a pre amp for the tablet, remote to control volume and track control for the tablet, and a hands free calling kit for my phone. In doing so, it auto interrupts the music for calls along with turning on the amps via the "mute wire" and a relay.
As for software, I used the stock apps along with tasker for the automation and equalizer for better audio control. I also use a volume widget as a back up since my parrot kit is my main volume control.
here is the stock dash before the install
{
"lightbox_close": "Close",
"lightbox_next": "Next",
"lightbox_previous": "Previous",
"lightbox_error": "The requested content cannot be loaded. Please try again later.",
"lightbox_start_slideshow": "Start slideshow",
"lightbox_stop_slideshow": "Stop slideshow",
"lightbox_full_screen": "Full screen",
"lightbox_thumbnails": "Thumbnails",
"lightbox_download": "Download",
"lightbox_share": "Share",
"lightbox_zoom": "Zoom",
"lightbox_new_window": "New window",
"lightbox_toggle_sidebar": "Toggle sidebar"
}
Now for the install
here is the "message center and AC control bezel removed, along with the new tablet bezel to aid in fitting the apposing aspect ratios
next I made a new AC bezel. I will attach this to the aftermarket dash kit that the radio was in before.
here is a shot of the AC controls mounted to the dash kit/bezel
Here is a picture of the bracket that holds the tablet in place.I used two existing mounts for some of the factory parts that are no longer there
now there is nothing left to do but put it all back together
Now this install was performed on a system that already had external amps. If you were to figure in the cost of amps, it may be cheaper to use a pre existing dash unit...but not near as cool
hmmmmmm i dont think this would be a great idea, but i would definitely look around for a car charger for it. For the power button, i think if possible put it in landscape mode, not portrait mode. But it'd be way easier if you mounted a phone of the same caliber. But it depends what suits your needs. Hope i helped
dB Zac said:
So I am going to mount a nexus 7 in the dash of my dodge and I need to get around a couple things. 1st I need to be able to charge the tab and have a working usb port. I I could simply unplug the charger when usb is needed but it would be better if I didn't have to. So is there a way to "t" this the usb to a charger or build a pass threw charger?
2nd thing is the power button. It will be permanently mounted so I will need access to the power button for reboots and such. I can try to make a mechanical extension or hard wire a remote button if possible. Can the board be soldered to or is it coated?
Any other ideas for the install are welcome! I hope this is the correct forum.
Click to expand...
Click to collapse
1. you could charge the Nexus 7 via POGO pins. You could make a dock with POGO pins. There's a thread about pogo pins in the Nexus 7 - Nexus 7 Accessories section. :good:
That's a good idea
Sent from my SAMSUNG-SGH-I747 using Tapatalk 2
Also, as far as the power button is concerned, I think it might be easier to utilize a magnet, emulating what a smart cover would do. It would be much safer and easier to implement.
Sent from my Nexus 7 using Tapatalk 2
Please explain, I'm not fallowing. Is there a magnetic "dock mode" switch?
Sent from my SAMSUNG-SGH-I747 using Tapatalk 2
Have you seen the ipad 3's magnetic cover - when you open it it powers on? Well I think this is what he is talking about. If you can find a magnetic cover, then you could use it on the nexus 7 instead of using the power button.
I see. Not really the solution I would be looking for, for two reasons: I really don't need a way to turn on the screen, I am simply going to set the developer option to "always on when plugged in" and the power source would be an on with key "ignition" and the most important reason would be to cycle the power in case a reset is needed.
Sent from my SAMSUNG-SGH-I747 using Tapatalk 2
This sounds interesting..
BUT.
Go to amazon.. search for small form factor (something similar ) Auto android pc..
You will find many very small android mountable pcs .150.00 and under with sd usb hdmi dvi on some s video..
then do a search for 7-10 inch(what ever size you can fit ) multi touch monitor . There are many of them..
I Have one of the small form factor android pcs connected to a old lcd tv .. kinda kewl it has gps and all built in ..
So i think for a just a small amount more money You can have something Better sorted for being installed in a automobile .
Good Luck... I
Most android pc's get terrible reviews, and to have something with a 7" screen would cost well over 200 and still wouldn't have jelly bean and Google navigation. I looked at the parrot unit, I even tried it at SEMA in Vegas. I it was clunky and slow for last year's standards. The off brand units are even worse.
Sent from my SAMSUNG-SGH-I747 using Tapatalk 2
Nexus 7 Car Audio Dash install
I have completed my nexus 7 install as my head unit in my 92 Dodge Diesel D350. These trucks have a din and a half radio in the lower portion of the dash, its hard to get to and see, fold out screens hit the "step" that is just above the radio position and once they are motored out, they end up in front of the AC controls. It just isnt a good option. Also since any in dash unit that compares feature wise to a Nexus 7 (besides audio output) would run about 800-1400 in price and would be to deep for the location I had in mind, it makes the tablet a no brainer.
I considered the Galaxy Tab 7 and tab 2 7.0 because of there HDMI output via dock but I just don't think I will be putting another screen in this truck so I opted for the better hardware at the same price as a used tab that would still work with AT&t.
One of my main goals was not to loose any of the functionality that I currently have in my set up. This includes, bluetooth hands free calling, and the basic automation that a true in dash has(i.e. on and auto play with key on and off and auto pause with key off) On top of that I was to gain google maps and internet connectivity along with android apps. In order to accomplish this goal, a combination of hardware and apps were used.
The hardware used includes a ar Charger 5V 2A charged bought on amazon that I hacked and wired in direct on an ignition source and a parrot MKI9000 that I use as a pre amp for the tablet, remote to control volume and track control for the tablet, and a hands free calling kit for my phone. In doing so, it auto interrupts the music for calls along with turning on the amps via the "mute wire" and a relay.
As for software, I used the stock apps along with tasker for the automation and equalizer for better audio control. I also use a volume widget as a back up since my parrot kit is my main volume control.
here is the stock dash before the install
Now for the install
here is the "message center and AC control bezel removed, along with the new tablet bezel to aid in fitting the apposing aspect ratios
next I made a new AC bezel. I will attach this to the aftermarket dash kit that the radio was in before.
here is a shot of the AC controls mounted to the dash kit/bezel
Here is a picture of the bracket that holds the tablet in place.I used two existing mounts for some of the factory parts that are no longer there
now there is nothing left to do but put it all back together
Now this install was performed on a system that already had external amps. If you were to figure in the cost of amps, it may be cheaper to use a pre existing dash unit...but not near as cool
OK this is something I think will be right up your alley guys. I will use the "screen always on while charging" setting and the "sleep in 15sec" setting to emulate the same auto power on and off of a head unit.
My question is, can I use tasked or some other app to make all media no later what I am listening to or watching, stop when the screen times out or charging is stopped?
This is a fascinating project, sometimes the apps themselves have those options in them. I'd look there first. I would love to see how the turns out. Good luck,
Sent from my Google Nexus 7 using xda app-developers app
Well I picked up another dash bezel the other day and decided to start making room for the tablet since I'm waiting on the parrot piece to come in.
Here is a photo of the day as it is now.
So the plan is to relocate the AC control's to the head unit spot and put the tablet up in the message center/ AC control spot
The stock area for the other items isn't quite the correct ratio so I will still have to make a bezel
Sent from my SAMSUNG-SGH-I747 using Tapatalk 2
Did some more work on the Tablet Project
O also used Tasker to emulate a head unit on and off function. So now the tablet wakes up and starts playing my music where ever I left off when the key is turned on and then the tablet screen, sleeps and the music is paused when the key is turned off. The tablet battery will act as the "always on" power lead and the charger will be connected to the accessory lead ( I may have to program in some delay or use the ign lead if tasker doesn't like the start cycle
Got it installed, I couldn't be happier with how it sounds. I still have to mount the A/C controls
Also, of any of you have a suggestion for a good charger to use that won't cause noise when hard wired, that would be great
Sent from my SGH-I747 using Tapatalk 2
I have actually done this with an Archos tablet myself! I can offer you one very useful piece of advice...
You most likely need to remove the battery and connect a 12 VDC->3.3 or 5 VDC DC-DC transformer. If you just leave it plugged in you will likely destroy the battery in about a year or less. When mine finally went I got random reboots from low power, sometimes it refused to turn on because the battery was barely able to supply the correct voltage. I had to solder my transformer leads directly to the motherboard but the Nexus 7 has a pluggable battery pack. Measure the battery at full voltage to see what voltage you need and buy the correct transformer. They are only a few dollars off ebay (lower quality) or digikey.com (higher quality). You don't have to worry about this right away but just know that it will most likely stop working reliably in < 1 year, so plan to either do this mod or buy a new battery.
Once I did the conversion all the problems have gone away and I'm now constantly at "47% charge".
Was it plugged into constant power or ign switched power? Mine is connected to switched power
Sent from my SGH-I747 using Tapatalk 2
dB Zac said:
Was it plugged into constant power or ign switched power? Mine is connected to switched power
Sent from my SGH-I747 using Tapatalk 2
Click to expand...
Click to collapse
Mine was constant power. If you are switched it should be good - must have missed that part, lol.
EDIT: Actually, that's a very good idea... I wonder why I didn't do that in the first place, lol. I'm looking to upgrade to a Nexus 7 and would like to build mine into the dash but would have to relocate some things. When on AC/USB power, Tasker would have the screen on and when on battery the screen would be off. Only problem could be if you went a few days without driving it would be dead when you turned the car back on. Maybe that's what I was thinking when I did constant power. Maybe there's a NFC device that could be read only when powered on... That could be on switched power and Tasker could use that to control the screen. Oooo or maybe use the 'headset plugged' condition and a switched power relay...
Spec sheet says 12 days of standby time though, so maybe it's not an issue...
MORE EDITS: I re-read through your posts and figured I'd add some more input if you are still looking for answers. What is it you need the USB for? I don't see why you couldn't hack up a USB cable to feed power to the power pins on the tablet side (charging the tablet) as well as the USB device side (power the device) but have the data pins go from the device to the tablet. I just use wi-fi file browsers to add/remove files from mine.
Removing noise is always a PITA especially alternator whine. There are various filters out there that should do the trick though. I think you'll have noise using switched power but the filters go on the audio side before the amp/head unit. (Something like this: http://www.bargainunlimited.net/ser...gdftrk=gdfV21887_a_7c254_a_7c4406_a_7cSNI_d_1)
Tasker can be set to stop media playback on screen off - at least if you use the stock music app. Others (Pandora/Spotify, etc) I'm not sure about. I'd bet there's a way though. In fact... if you had to you could set Tasker to kill whatever app when the screen turns off and launch it again when the screen turns on.
Power button could be an issue to extend but should definitely be possible if you want to play around on the insides. You could get an app that adds power off/restart as menu options or widgets but if the whole thing locked up you would have to pull the battery. You could add a small switch inline from the battery pack so you could interrupt power with a button press effectively "pulling" the battery and plugging it back in.
Other thoughts/stuff I missed? I love doing this kind of stuff so I'm happy to add any input.
The head set idea won't work unless you hardwired it. All I had was a 90deg elbow with nothing on the other end and it still detected a head set
As for the tab dieing. I use Tasker to shut off all radios when not charging. In that state it will last 2weeks lol.
Sent from my SGH-I747 using Tapatalk 2

[Q] Battery Connection Voltage/Amperage

ok here's what I want to do.
Permanently integrate a nexus 7 in my car dashboard in the double din radio opening
Remove the battery from the nexus 7 and hardwire to always on power from the car battery
Hardwire the power button to a button installed in the dash
Dashmount a usb port connected via otg for hotswapping media
Hardwire a potentiometer into the dash for volume control
all of the above is fairly simple except for power supply, otg+charging is a possible solution but a car battery wired solution is far better so what i need is information on what the battery pins supply in terms voltage/amperage so i can create a 12v to direct power converter or a device that already does this. any help is appreciated TIA
bump, if someone knows i could really use this info
b22ri22an said:
ok here's what I want to do.
Permanently integrate a nexus 7 in my car dashboard in the double din radio opening
Remove the battery from the nexus 7 and hardwire to always on power from the car battery
Hardwire the power button to a button installed in the dash
Dashmount a usb port connected via otg for hotswapping media
Hardwire a potentiometer into the dash for volume control
all of the above is fairly simple except for power supply, otg+charging is a possible solution but a car battery wired solution is far better so what i need is information on what the battery pins supply in terms voltage/amperage so i can create a 12v to direct power converter or a device that already does this. any help is appreciated TIA
Click to expand...
Click to collapse
Can't you just use the USB port to charge it? it takes 5V, and 2A. With a car battery it should have enough amps, the voltage is what you'd need to regulate.
But if you really want to take out the battery instead...can't you just use a volt meter to see what the N7 draws from the battery? I'd guess it's 3.7v lithium ion but I'm not positive. I couldn't find the specs on google either..
As far as I have read there are some major difficulties getting otg+charging to work at the same time and I need the storage space provided by external storage. Having the car power source replacing the nexus 7 battery would eliminate that problem altogether.
I was hoping that someone here had known the voltages since I don't currently own or have access to a multimeter to test for myself. Knowing the voltages in advance would give me the opportunity to see what would be entailed financially to build the project and determine if its its financially acceptable to me, if the project isn't viable the money spent on the multimeter to do the tests would be wasted as it's not something I need for anything other than this particular project. So in the interest of trying to save $20 I figured I would ask here first and that there was a good chance that someone might have the information I needed.
b22ri22an said:
As far as I have read there are some major difficulties getting otg+charging to work at the same time and I need the storage space provided by external storage. Having the car power source replacing the nexus 7 battery would eliminate that problem altogether.
I was hoping that someone here had known the voltages since I don't currently own or have access to a multimeter to test for myself. Knowing the voltages in advance would give me the opportunity to see what would be entailed financially to build the project and determine if its its financially acceptable to me, if the project isn't viable the money spent on the multimeter to do the tests would be wasted as it's not something I need for anything other than this particular project. So in the interest of trying to save $20 I figured I would ask here first and that there was a good chance that someone might have the information I needed.
Click to expand...
Click to collapse
oh ok..well have you taken a look at the battery? It should just be 3.7v, I don't think it would be too hard to find which pins it is. Maybe take a LED and test it across the pins?
Also, I have heard reports OTG + charging is working fine on CM10 with a patched kernel. you might want to check this thread: http://forum.xda-developers.com/showthread.php?t=1934722
mvmacd said:
oh ok..well have you taken a look at the battery? It should just be 3.7v, I don't think it would be too hard to find which pins it is. Maybe take a LED and test it across the pins?
Also, I have heard reports OTG + charging is working fine on CM10 with a patched kernel. you might want to check this thread: http://forum.xda-developers.com/showthread.php?t=1934722
Click to expand...
Click to collapse
I've been participating heavily in the arena of OTG + charging simultaneously, as well as using USB audio.
To answer the OP's question directly: I have demonstrated (to myself) that I can power down my Nexus 7, disconnect the battery connector, plug in my y-splitting OTG cable with power in one plug, and an unpowered USB hub in the other plug. [Plugged into the USB hub is a flash drive, USB DAC, and I'm sure a keyboard would also be an option.] Then I turn on my Nexus 7, and in the OS it shows the battery at 0%, but charging (obviously it's not actually charging without the battery present...).
I even booted up the Nexus 7 normally, with all the same stuff connected to USB, and then disconnected the battery connector... and the Nexus 7 remained on!
I've thought about integrating some sort of tactile switch that essentially disconnects the battery whenever the switch is depressed. So then part of the car mount could be a little protrusion that presses this switch whenever the tablet is inserted into the car mount. That way whenever the tablet is removed from the car mount, the battery will take over without removing power from the motherboard.
MetalMan2 said:
I've been participating heavily in the arena of OTG + charging simultaneously, as well as using USB audio.
To answer the OP's question directly: I have demonstrated (to myself) that I can power down my Nexus 7, disconnect the battery connector, plug in my y-splitting OTG cable with power in one plug, and an unpowered USB hub in the other plug. [Plugged into the USB hub is a flash drive, USB DAC, and I'm sure a keyboard would also be an option.] Then I turn on my Nexus 7, and in the OS it shows the battery at 0%, but charging (obviously it's not actually charging without the battery present...).
I even booted up the Nexus 7 normally, with all the same stuff connected to USB, and then disconnected the battery connector... and the Nexus 7 remained on!
I've thought about integrating some sort of tactile switch that essentially disconnects the battery whenever the switch is depressed. So then part of the car mount could be a little protrusion that presses this switch whenever the tablet is inserted into the car mount. That way whenever the tablet is removed from the car mount, the battery will take over without removing power from the motherboard.
Click to expand...
Click to collapse
Lol, yes, I think I had you in mind when I said that.. I'm still waiting for my Y cable. I won't get it till at least 1.5 weeks..
MetalMan2 said:
I've been participating heavily in the arena of OTG + charging simultaneously, as well as using USB audio.
To answer the OP's question directly: I have demonstrated (to myself) that I can power down my Nexus 7, disconnect the battery connector, plug in my y-splitting OTG cable with power in one plug, and an unpowered USB hub in the other plug. [Plugged into the USB hub is a flash drive, USB DAC, and I'm sure a keyboard would also be an option.] Then I turn on my Nexus 7, and in the OS it shows the battery at 0%, but charging (obviously it's not actually charging without the battery present...).
I even booted up the Nexus 7 normally, with all the same stuff connected to USB, and then disconnected the battery connector... and the Nexus 7 remained on!
I've thought about integrating some sort of tactile switch that essentially disconnects the battery whenever the switch is depressed. So then part of the car mount could be a little protrusion that presses this switch whenever the tablet is inserted into the car mount. That way whenever the tablet is removed from the car mount, the battery will take over without removing power from the motherboard.
Click to expand...
Click to collapse
Am i understanding you correctly? If i unplug the battery, and just have the OTG cable plug into the charger, it would be able to power on and off and run just fine?
ho9984 said:
Am i understanding you correctly? If i unplug the battery, and just have the OTG cable plug into the charger, it would be able to power on and off and run just fine?
Click to expand...
Click to collapse
This was how it worked while the N7 was running Jelly Bean 4.1.2. I can't guarantee it would operate the same on 4.2.2.
MetalMan2 said:
This was how it worked while the N7 was running Jelly Bean 4.1.2. I can't guarantee it would operate the same on 4.2.2.
Click to expand...
Click to collapse
Someone tried it on Reddit. Removed the battery and tried powering it on with only OEM charger. The screen just flickered. They were on 4.2.2
I am curious about removing the battery and hardwiring as well as I am gathering parts to put my Nexus 7 in my car dash. The problem w/ the OTG route - it gets pretty hot down here and I'm afraid the battery will have some long term issues (ie...could leak/explode). So, hardwiring it would be preferred.
Any ideas for hardwiring?
with the new nexus 7 coming out I am just going to mount the wireless charger behind the tablet dock, now I just hope otg is supported with the slimport on the new nexus 7

The ultimate solution for In-car entertainment, but how ?

Hi folks.
I am looking into installing my Nexus 7 permanently in the car, needing the use of being able to charge it, and use an USB DAC at the same time.
This page promises to have an ROM that is able to do that, but I have been unable to get that to work at all. I do not want to upgrade to 4.2.x due to the known bugs, so it's 4.1.2 for me at the moment.
http://goo.gl/fQ2LL
Using a stock ROM i am able to start/stop playback with Tasker registering "AC charge" - How do i go about this when using an OTG-Charge ROM ?
I do not want to charge the tablet when i'm not driving the car, what happens to the USB DAC when the power is cut, does it lose sync with the Nexus 7, and requires a reboot to function again?
So in short this is what I had in mind:
Ignition on -> Tasker registering AC power, starts playing music.
Ignition off -> Tasker registering power is off, pauses music, tablet go to sleep after at set amount of time.
I am realising that this may not even be possible, I can't see how the USB connection should survive, when the power is being cut, but maybe some of you more experienced guys can chime in on this subject.
I would rather not make any modifications to the tablet, but if this is neccessary to make it work, i'll have to do it (e.g. feed power directly to the battery with Li-Ion charging circuit.
Any other ideas of letting Tasker know that the car is started ? I have a bluetooth handsfree in the car, but that is connected to my iPhone, so I cannot use that as a wakeup function when that connects as Tasker do not have any "Blutooth Near" functions...
I've tried to connect 5V to the POGO pins on the side, but it won't charge the battery this way (it's enabled in the 4,2,x ROM afaik)
I've wired up my USB OTG cable like this: http://goo.gl/vqc3F
Any ideas is very welcome, as I cannot see how to do this.
Regards,
// Per.
I'm looking at doing the same thing but also a USB flash drive and also a Joycon EX Steering Wheel Control PC Interface via USB.
What I'm debating on doing is instead of hooking the charger to the ignition to turn on n off with he car I'm thinking about using constant power and hooking up an input on the joy on to the ignition 12V and setting the screen to come on n off with the car.
Unfortunately this means the tablet will be on the charger 24/7 but not sure how else to make sure everything reconnects as it should.
Anyone else have any ideas?
Sent from my Nexus 7 using xda app-developers app
I'm planning on doing a car install with all the bells and whistles also:
Joycon Ex
USB DAC (E10 or Behringer?)
USB Hard drive
Powered USB Hub
From what I've read of other threads, some people have trouble getting the DAC to reconnect after power changes, and some don't. In general, the rule of thumb is as long as the N7 is booted with the DAC attached, you should be able to unplug (or stop powering it), and then start again. There seem to be some behavioral exceptions with this (e.g. if you don't stop audio playback before putting the tablet to sleep with tasker, when it wakes up, you may need to fiddle with it before it starts working again).
It's a long thread, but I'd recommend reading this:
rootzwiki.com/topic/30615-can-you-charge-usb-host-mode-simultaneously/page__st__140
Timur has provided multiple patches that are trying to satisfy everyone's exceptions in trying to get this working.

[Q] Car installation question

Hello!
I recently installed my Nexus 7 in my Honda Civic and I love it. However, I have some questions!
I am using Timurs USB rom and it works very well. I was using Fixed Installation mode with an OTG-Y cable and the tablet was going to sleep and waking up when the car was turned on or off just fine. However, the OTG-Y cable I was using was faulty and was not allowing the tablet to charge.
I now have it connected without the OTG-Y cable but Fixed Installation mode in Timurs USB rom requires an OTG-Y cable to work. I have tried to duplicate the same behaviour using tasker but I can't get the tablet to turn on reliably with the car. Sometimes it works, however it usually takes a few tries. From what I can tell this because of a battery state where it is powered but not charging.
I am wondering if there is a way I can use Fixed Installation mode in Timurs USB rom without an OTG-Y cable? or if thats not possible, maybe someone can provide some tips for making tasker reproduce the same behaviour?
Thanks!
Jarred
I can't answer your question, but do you have any pictures of it installed? I have a Honda civic 2013, but can't find a place to install it that I like.
Sent from my Nexus 5 using Tapatalk 2
I have instaled my N7 on Civic RS (7 gen). But removed bat - reason at -10C Nexus don't want to start =). About not charging your install - you need good wiring about 0.75 mm2 or 1mm2 copper wire and as short as u can from DC-DC converter to succes charge. And Fast charge settings on USBROM.
layt said:
I have instaled my N7 on Civic RS (7 gen). But removed bat - reason at -10C Nexus don't want to start =). About not charging your install - you need good wiring about 0.75 mm2 or 1mm2 copper wire and as short as u can from DC-DC converter to succes charge. And Fast charge settings on USBROM.
Click to expand...
Click to collapse
Thank you for the info, but this is not relevant to my question. My tablet is charging just fine.

Categories

Resources