Tablet PC as Carputer?

[solidxsnake]

Bump to this.

 

 

Also, anyone with the latest Timur rom on marshmallow? I am noticing two issues: when the tablet 'wakes up', the screen does not necessarily turn on. I have to touch it and then it turns on. Second, the battery still gets depleted during deep sleep mode. 'Tablet idle' is the apparent process that drains it. Nothing else. If I power it down and leave it alone for like 5 days straight, then turn it back on, the battery is still full. So it is not a battery issue.

Are you guys having similar issues?

 

 

Then it's not in deep sleep mode. Is it "Awake" when the battery is draining? If it's not, then the battery shouldn't be draining at all.

[xt2005bonbon]

That's the thing. No it does not show as 'awake', but when you click on 'tablet idle' and check out the details, it shows 'computed power use' like 800mAh of use during the past 9 days (which is the number of days in which the tablet was supposed to be 'deep sleeping'). So it went from 100% to like 40% or so.

 

I made sure that all RTC alarms are unchecked. But still not helping.

 

Very annoying.

[utc_pyro]

Making progress on my Nexus 7 LTE install thanks to solidxsnake and his custom ElementaX kernel enabling fixed install mode for LineageOS 14.1. Software is just about there, just need to add the automation.

 

I rotated the USB plug 90* tonight like several of you, and applied artic silver between the CPU and RF shield, and the RF shield and heat spreader. This should help stability running at 2ghz.

 

 

Then I hooked up a 5.2V PSU, modified hub, and USB switcher. Two of the hubs ports are rigged up to only activate with a 12V relay for backup cameras and the like. The USB switcher will let me flip the another hub with the wideband and OpenPort between the Nexus 7 and a tuning laptop.

 

 

What is everyone doing for mounting the tablet to the bezel? As this is a LTE model with ~6 antennas I'm apprehensive about using metal brackets.

 

Also is there a recommended anti-glare screen cover people are using?

Edited March 13, 2018 by utc_pyro
Typing post on iPhone = lots of typos

[xt2005bonbon]

overclocking huh? Interesting.

 

I can't really give you much feedback as to mounting the tablet to the bezel since I used the usdm oem bezel. In my case, I used jb weld between the back of the tablet back cover and the vents on each side. Super sturdy but definetely sucky if you have to seperate the tablet from the bezel.

 

I like your home screen. Planning to use gestures for safe driving too?

[solidxsnake]

Making progress on my Nexus 7 LET install thanks to solidxsnake and his custom ElementaX kernel enabling fixed install mode for LineageOS 14.1. Software is just about there, just need to add the automation.

 

I rotated the USB plug 90* tonight like several of you, and applied artic silver between the CPU and RF shield, and the RF shield and heat spreader. This should help stability running at 2ghz.

 

[ATTACH]262961[/ATTACH]

 

Then I hooked up a 5.2V PSU, modified hub, and USB switcher. Two of the hubs ports are rigged up to only activate with a 12V relay for backup cameras and the like. The USB switcher will let me flip the another hub with the wideband and OpenPort between the Nexus 7 and a tuning laptop.

 

[ATTACH]262962[/ATTACH]

 

What is everyone doing for mounting the tablet to the bezel? As this is a LTE model with ~6 antennas I'm apprehensive about using metal brackets.

 

Also is there a recommended anti-glare screen cover people are using?

 

I've already shown you my tablet mounting scheme, but I'll re-iterate it here since I don't think I've posted it publicly:

 

As for mounting, I used some metal brackets and bolts/nuts and cut some slots in them to give me enough flexibility to align the tablet to the angle of the bezel. Mounted a final bracket to the back of the tablet with some very low-profile screws and nuts. Here's some pictures that should get the point across: https://imgur.com/a/uans1

 

I originally tried high-temp hot-glue which worked okay during the summer, but wouldn't hold with heat running. The brackets were by-far the best solution, and honestly not particularly difficult or time-consuming when I actually sat down and tried it.

 

 

I don't think this type of mounting will give you any problem, even with the LTE (coming from a microwave engineer). I'd give it a shot first, at least.

 

I use this as a screen protector/diffuser. Absolutely necessary since I wear polarized sunglasses, and without a diffuser the LCD of the tablet is completely invisible: https://www.amazon.com/Protector-Tech-Armor-Anti-Glare-Anti-Fingerprint/dp/B00E9QK2MW

[utc_pyro]

For those with Nexus 7's in dash: Do any of you find when you get in your car your tablet is off? Particularly that it's off, then boot loops twice (gets all the way into the OS then says "shutting down"), then finally behaves? I'm trying to debug some odd issues. This thing worked great on my bench, but is falling apart in production.

[nevets27]

How do you have it powered and is it rebooting due to low battery?

 

I haven't got mine to not chew through the battery while asleep or while being used. I actually loose power. Tried just about everything. Though I think I know the problem is with my USB board/connector. I mean I know it had a problem when I bought it second hand so I replaced it but it still doesn't seem to pull enough current even though the cable and adapter are capable.

[utc_pyro]

12v-5.2v converter powered off ACC/IGG1. OTG y-cable plugged into that, and a second set of wires directly to the hub. Yes I know that creates a ground loop.

 

Battery is normally at 90% or so once the thing fully recovers.

Edited May 20, 2018 by utc_pyro

[xt2005bonbon]

Which version of Android are you running?

[utc_pyro]

Timurs ROM on android 6.0.1

[xt2005bonbon]

In my 05, I have Timur rom 5.x.x without any issue whatsoever. I also have (on my test bench) another nexus 7 with 6.0.1. It runs fine too but has one issue: when it supposedly goes into deep sleep mode (e.g. when charging is interrupted), the screen turns off but the tablet is actually not sleeping for some reason. The battery is slowly draining and that's not good. I still have not found out what is causing it.

 

Just to check, I powered off the tablet completely with a full battery. 3 weeks later, turned it on and only lost like 3%! When she is supposedly in deep sleep mode, she could loose 25% in a day. Not good. Anyway, don't know if that is related to your issue somehow.

[solidxsnake]

utc: Did you run into issues running the modded E-X I sent you? I've been using that + A7 on my tablet (which is now in the Accord, instead of the LGT) and it's been running great.

[Infosecdad]

In my 05, I have Timur rom 5.x.x without any issue whatsoever. I also have (on my test bench) another nexus 7 with 6.0.1. It runs fine too but has one issue: when it supposedly goes into deep sleep mode (e.g. when charging is interrupted), the screen turns off but the tablet is actually not sleeping for some reason. The battery is slowly draining and that's not good. I still have not found out what is causing it.

 

Just to check, I powered off the tablet completely with a full battery. 3 weeks later, turned it on and only lost like 3%! When she is supposedly in deep sleep mode, she could loose 25% in a day. Not good. Anyway, don't know if that is related to your issue somehow.

 

What do you have connected to your tablet when in deep sleep? I had a USB hub and/or USB DAC that was sucking the power out when I was supposedly in deep sleep. So far the replacements are doing much better and I'm only losing about 1% per 24hrs of deep sleep.

[utc_pyro]

utc: Did you run into issues running the modded E-X I sent you? I've been using that + A7 on my tablet (which is now in the Accord, instead of the LGT) and it's been running great.

 

It was just too needy and unpolished without PEM. It worked, but it didn’t feel OEM quality. Tasker was too slow and popped up too much stuff, and it would sometimes get caught in strange states.

 

Is it possible to load PEM on the E-X rom? If I could use that with your patches E-X it would be perfect.

 

Some of the issues seems related to the launcher I’m using though. Bugs related to it followed to the earlier rom, may need to find a different launcher. I’m getting about 10% power drain per day with no power reconnect events and this has followed between the builds.

Edited May 22, 2018 by utc_pyro

[xt2005bonbon]

What do you have connected to your tablet when in deep sleep?

 

I have nothing connected to it except the otg cable. If I cannot find a solution, I may just go back to 5.x.x timur version.

 

II’m getting about 10% power drain per day with no power reconnect events and this has followed between the builds.

 

My N7 with timur 5.x.x has surprisingly just like 0-3% drain after 3-5 days of deep sleep. I do have a (powered) USB hub connected to it with back up camera, usb stick, usd dac, joycon exr, and vag com cable. Now that it is nice and stable, I am always wary to update any apps...

[solidxsnake]

It was just too needy and unpolished without PEM. It worked, but it didn’t feel OEM quality. Tasker was too slow and popped up too much stuff, and it would sometimes get caught in strange states.

 

Is it possible to load PEM on the E-X rom? If I could use that with your patches E-X it would be perfect.

 

Some of the issues seems related to the launcher I’m using though. Bugs related to it followed to the earlier rom, may need to find a different launcher. I’m getting about 10% power drain per day with no power reconnect events and this has followed between the builds.

 

 

I'm not positive. It's Timur's "custom" software, so I don't know if it has any custom hooks into his kernel (probably not).

 

 

I'm interested in what was "too slow" or what stuff was popping up... My scripts run pretty seamlessly. It's not instant power-off/power-on, but that could be fixed if I installed a delayed power-off relay like I used to have, which could bridge the cases where the setup loses power for a couple seconds (cranking, or having to re-start the engine, etc.).

[utc_pyro]

I'm not positive. It's Timur's "custom" software, so I don't know if it has any custom hooks into his kernel (probably not).

 

There is at least one other ROM out there that was trying to make a 7.1 version of Timurs kernal, and they had PEM running on it. Unfortunately the dev had an issue with the LTE version of the tablet and only supports the WiFi version though. So that points to it likely working?

 

I'm interested in what was "too slow" or what stuff was popping up... My scripts run pretty seamlessly. It's not instant power-off/power-on, but that could be fixed if I installed a delayed power-off relay like I used to have, which could bridge the cases where the setup loses power for a couple seconds (cranking, or having to re-start the engine, etc.).

 

Mostly the power on wasn't instant, and it took it a little while to turn off airplane mode and low power mode. Timurs PEM kind of mask all of that with it's status screen, and thus feels more polished. Turning off was also kind of delayed as well due to having to try and stop music and apps in tasker. I mostly use Spotify, Waze, and BTSSM on the table and they all like to keep running.

 

I kind of have the expectation that I can take the car to the shop and they people there have no idea it's actually a tablet in the dash. Maybe my expectations are too high though.

[solidxsnake]

There is at least one other ROM out there that was trying to make a 7.1 version of Timurs kernal, and they had PEM running on it. Unfortunately the dev had an issue with the LTE version of the tablet and only supports the WiFi version though. So that points to it likely working?

 

 

 

Mostly the power on wasn't instant, and it took it a little while to turn off airplane mode and low power mode. Timurs PEM kind of mask all of that with it's status screen, and thus feels more polished. Turning off was also kind of delayed as well due to having to try and stop music and apps in tasker. I mostly use Spotify, Waze, and BTSSM on the table and they all like to keep running.

 

I kind of have the expectation that I can take the car to the shop and they people there have no idea it's actually a tablet in the dash. Maybe my expectations are too high though.

 

 

Ah, I see. Yeah... you'd need to write your own scripts/software to do that level of integration. Running that sort of stuff through a user-space app like Tasker is going to be much slower than doing it at a lower level.

 

 

I don't see how flo vs deb should make any difference for PEM, but having not looked into it myself, I can't say for sure. I wouldn't be surprised if that dev didn't have a deb tablet to test on.

[utc_pyro]

I don't see how flo vs deb should make any difference for PEM, but having not looked into it myself, I can't say for sure. I wouldn't be surprised if that dev didn't have a deb tablet to test on.

 

The dev was trying to do a lot of other stuff that I really dont care about, and broke his deb build in the process. Something having to do with USB DAC's.

 

Looking at the install script for PEM 107 it looks like you can probably just install the zip on top of 7.1 and it put the file in the correct place. Going to rip the tablet out of the dash tomorrow and try 7.1 again.

 

Looking at what Timur did a little, two questions:

Is there anything in services.jar that could be related to PEM?

If one was to modify the install script, is the binary version really needed?

[solidxsnake]

The dev was trying to do a lot of other stuff that I really dont care about, and broke his deb build in the process. Something having to do with USB DAC's.

 

Looking at the install script for PEM 107 it looks like you can probably just install the zip on top of 7.1 and it put the file in the correct place. Going to rip the tablet out of the dash tomorrow and try 7.1 again.

 

Looking at what Timur did a little, two questions:

Is there anything in services.jar that could be related to PEM?

If one was to modify the install script, is the binary version really needed?

 

The install scripts have always been plaintext, in my experience. I'm not sure what "services.jar" you're referring to (I assume it's something out of Timur's ROM), but since it's java bytecode, if you really needed you could put it through a decompiler and it'll spit out mostly readable Java code.

[utc_pyro]

So I can pretty much correlate this shutdown issue with heat. It died after sitting outside for three hours yesterday, when it will go overnight without a hitch. The other day when it died while driving the sun was hitting the screen, also pointing toward heat issues.

 

 

Today I took the FLIR camera out and it was sitting at 68c on a fairly warm day before starting the car. Per some specs Infosecdad found that’s over the discharge temperature limit of the battery, and likely why it’s shutting down.

 

 

Fortunately it appears there is enough air leakage in the HVAC vents to cool the tablet down once the car is started. It starts working around 60C.

 

So now the question: am I the only one that runs into this issue? Is there something different about my setup that causes it to heat up more in the sun? Is there a way to change the max battery charge voltage and max discharge temperature to force it to keep working safely?

 

I’m running an ASUS brand anti-glare screen protector and the tablet is mounted via a hacked up case that came with it. I wonder if the screen protector is allowing it to absorb more radiated energy and case not letting it radiate back into the dash. That or the sugru around the edges of the tablet is transferring thermal energy from the bezel heating up?

[solidxsnake]

It may be the case trapping heat? That said, I suppose my LGT had less heat to begin with, even in the sun, since I have CR45 on all the windows. I never had temperature shutdown issues. I wouldn't try and to bypass any battery safety, though... Li-Ion batteries are nothing to mess around with.

[funkycharms]

I dont have random shutdown issues, but sometimes the screen doesn't start up with power from the car. I will note conditions next time I have the issue

[Infosecdad]

...

 

So now the question: am I the only one that runs into this issue? Is there something different about my setup that causes it to heat up more in the sun? Is there a way to change the max battery charge voltage and max discharge temperature to force it to keep working safely?

 

I’m running an ASUS brand anti-glare screen protector and the tablet is mounted via a hacked up case that came with it. I wonder if the screen protector is allowing it to absorb more radiated energy and case not letting it radiate back into the dash. That or the sugru around the edges of the tablet is transferring thermal energy from the bezel heating up?

 

I would expect the case is helping insulate/retain heat on the back. Unscientific surveys with other tablets in the past have led me to that conclusion. Curious to see what the temp would be in there if you had a sun shade in the windshield. I wouldn't mess with trying to get the battery to operate at a higher temp, I would look more toward how to keep it cooler if possible. Could you mount it without the case or drill a bunch of large holes in the case so that it's just a lightweight skeleton of a case?

[nevets27]

I would suggest trying to do the no battery mod as that will 1)eliminate the over heating battery shutdown and 2) keep the tablet actually cooler as its not charging a battery.

 

I had planned to cut open the back of the case and get some thermal double sided tape and stick a heat sink to the heat spreader to pull some heat away from the tablet.

 

My initial workings with the nexus on timurs rom is going poorly though. Seems all good "on the bench" pulling power and it seems to be in deep sleep and slips battery. Put it in the car and it chews through battery and dies or kills the cars battery if I leave it plugged in the constant 12v. Worse is it won't pull enough current and slowly dies while using it.

 

So my only hope is a the no battery mod but first fixing the battery drain issue. It might have something to do with my repaired usb port but either way it's not working well right now at all.