[Nexus 7 Android Development] machmanx:
-So the audio long turnover issue was actually the Optipop ROM. Switched to Chroma ROM and that issue was gone.

-It still doesn't charge though. I wonder if there's a difference between OTG + charging and OTG + fastcharging because I seem to recall that the Nexus 7 can detect if you're charging from an adapter vs a computer port. It would detect the adapter as AC power or something. I mean mine works on Autodroid flawelessly. The slow charge issue that some complain about could be because their setups are not being recognized by the tablet as an AC source (aka over 500mA capable charging port). I'll try your suggestion though. However the way I setup my car system is in a way that lets me remove the tablet from my car easily. So I need that simultaneous OTG + charging operation.

-The volume issue remains.

More issues:

-AudioFX does not change anything in the audio. Sounds the same regardless of settings

-I don't see the typical SuperSU messages that I used to see with Autodroid

So I'm going to try to install that Power Manager app. Maybe it will fix the problem. I'll report back.

Edit 1: Power Manager app reports successful install but no icon or anything. Same with BusyBox...no icon.

Edit 2: Used QuickShortcutMaker to get the settings option of Power Event Manager accessible. And through this I confirmed that SuperSU is working.

Edit 3: Power Manager app solved my charging issues. With Fastcharge enabled my tablet properly charges with OTG. Also my volume issue was a result of my audio app, Rocket Player. I use PowerAmp now and music is good.

Initially Power Manager app didn't work the way I set it up to. You have to wait 10 seconds or so before changing the Fixed Install Mode option so that SuperSU can catch it and give it permission. It's not a quick reaction program. So set the other options the way you want slowly or quickly, but give some time before toggling the Fixed Install Mode. If that doesn't help, try installing SuperSU with TWRP. In Chroma ROM you won't get the program icon, but the updated files may update the built-in SuperSU in the ROM. Also, a restart is required if you enable Fastcharge. So don't panic if the system fails to charge when you disable the option. Enable and restart will fix it.

Edit 4: If a restart fails to get the charging working, then try unplugging and replugging the USB cable. After that, the system should properly charge when key is put to ACC or ON position. It seems that when you use the tablet for anything else while the OTG cable is unplugged, it tends to "forget" the FastCharge capability. So just unplug the cable, restart the device, replug the cable, unplug the cable, wait for a few seconds, and then replug the cable. Charging should be restored.

The ONLY issue I have currently is that the PowerOff event is somewhat unreliable as someone earlier reported in this thread. When that happens, turn your key to ACC or ON position, wait 2-5 seconds, then turn key to OFF position. Then the PowerOff event will kick in and sleep mode will activate. A minor nuisance but something I'm willing to tolerate. (Note: If you use the tablet as a car only device and don't mess with it, the sleep mode is actually pretty reliable. It's when you do other things on it that take away that reliability.)

So yeah, thanks for all your work, Sgt. Meow. This turned out great for a device that doesn't even support all these features and you managed to port it to Lollipop. Here, have a lollipop :p

Hopefully the above will help others. Now for my question: How do I increase the precision of the volume control? Like increase the number of steps or increments between 0 and Max volume? Is that a Kernel or ROM setting? (all of this is part of the same question BTW)