Ignition-Off Head Unit Status setting possible with screen off?

slizzap

I have a question regarding the usage of the Ignition-Off Head Unit Status setting, which can be found in Settings -> Vehicle -> Startup Settings -> Ignition-Off Head Unit Status.

The usage of this is pretty self-explanatory. For when the car key switches from ignition/accessory power ON -> OFF, this allows you to configure whether it sleeps for a period of time or goes into shutdown mode. This is a great setting, but in testing I found that when I set this to my preference of 5 minutes and I disconnect the accessory wire, the screen remains on for 5 minutes. Is it possible to use this setting while the screen is off? I'm coming from a different manufacturer Android head unit that had a similar setting, and with it when configured it would shut off the screen as you would expect when turning off the car, but it would remain powered on for the configured time before going into the deep sleep mode.

In case this is not currently possible, then please turn this into a feature request. Here's the issue I'm trying to workaround. I have my entire music library on a USB flash drive. I have an amp driving 2 sets of components and a subwoofer, so sound quality is important. As a result, I have 350 GB worth of FLAC files on a USB flash drive. When the Android head unit goes into deep sleep mode, the USB drive is disconnected/unmounted. Some music players, such as Poweramp that I use, doesn't like when the storage is unmounted. So I need to use utilities like Tasker to ensure the shutdown process of the head unit pauses the music and exits out of the app (prevents crash, loss of placement in the currently playing song, and rescans of the library). When the system starts, I put in a delay to ensure the USB drive is mounted before it restarts Poweramp and unpauses the song, leaving me in the exact same spot in the song. I like to have my unit NOT go into deep sleep until the car has been off for 5 minutes. This way if I'm just filling up my car with gas or picking up food, the unit fires up right away when I return. However, I definitely don't want the screen to be on because it shouldn't be displaying anything when I'm not in the car and the car is locked.

I'm also assuming there is currently no way to prevent USB storage from unmounting during the deep sleep mode. If there is, please let me know.

Thanks.

DUDU-Meng

slizzap
First issue: The function you're adjusting is called ACC power-off delay. This is a straightforward logic that requires no further discussion. It has nothing to do with the sleep mode you mentioned. The sleep logic activates after ACC power is off and the screen is off for 5 minutes.

Second issue: Memory playback should work fine. If you're using a very large USB storage device, slow read speeds after startup might prevent normal playback.

slizzap

Well, it looks like we can disregard most of my post here. I just found that most of my testing up until now has been flawed largely due to wireless issues. I posted another thread about that and it looks like I'm going to need to get my unit exchanged.

I was just able to confirm your statement that even with the Ignition-Off Head Unit Status set to the default of Sleep/0 seconds, the unit doesn't actually go into a deep sleep state until 5 minutes after ignition is turned off. This default is perfect for my needs and this setting is no longer necessary for my needs.

Regarding the USB flash drive, it's not a matter of "slow read speeds". When the unit goes into deep sleep mode after 5 minutes, it unmounts any external storage connected to it. So when the device awakes from the deep sleep mode, it typically takes 5-10 seconds for that storage to re-mount. Meanwhile, if that app was playing when it was shut off, DUDU7 will resume upon wake. Poweramp will start skipping tracks because it resumes before it sees the storage. Once it finally attaches, Poweramp resumes, but at that point it's lost the place in the current track and it's skipped about 5 tracks. This is where Tasker can help with a start delay after awaking from deep sleep. You can confirm all this by connecting a USB flash drive and once the system resumes from wake just open Files...if you do it fast enough you'll see the USB drive is not yet seen. It's the nature of Android and I've yet to see any Android head unit behave differently, so this is not specific to DUDU7.

Thanks for the input.

DUDU-Meng

slizzap
After 5 minutes of power loss, the ACC enters sleep mode, at which point the USB power supply is disconnected. USB devices cannot remain powered.