Visually silent power on / shutdown for Armbian - Possible?


bozden
 Share

1 1

Recommended Posts

Using legacy Ubuntu desktop image (currently with OPi One)... The application will be in a public place and will be shutdown/power up by a personnel.

 

Whenever my application starts, I have full control of the display area. On the other hand:

* At the very startup boot process with armbian logo is shown

* Desktop does uploaded and shown shortly (my application starts with automatic user login)

* In case of a shutdown (button press, IrDa, remote control etc) the desktop is shown again, screen gets blank and up again, shows login and shuts down (do your boards do that?)...

 

How can I prevent these? What I tried:

* Looked if I could turn on/off HDMI output (just got confused)

* Cleaned away desktop (icons, panel, wallpaper) and used a clear background (but it is seen several seconds anyways)

 

What can I do? Any pointers?

 

PS: The solution I seek needs to be display independent. Sometimes X brand projector, sometimes Y brand TV, new, old etc... But controlling the device through HDMI is an option too (if only I knew how)...

 

Link to post
Share on other sites

Armbian is a community driven open source project. Do you like to contribute your code?

Nope, it is for a local museum... Non-profit :) They have looping media players and I try to make them button controlled... But of course it can go commercial in the future...

 

I examined both kiosk and digital signage first but decided to go in Armbian way to have more control... I don't know if I made a mistake or not thou...

 

Link to post
Share on other sites

@tkaiser

@jernej

I definitely could turn off the display output but cannot get it back with "4 10" into param :(

(FYI: This is OPi One with legacy Ubuntu desktop running Armbian 5.27)

 

To turn of:

echo "switch" > /sys/kernel/debug/dispdbg/command
echo "disp" > /sys/kernel/debug/dispdbg/name
echo "0 10" > /sys/kernel/debug/dispdbg/param
echo "1" > /sys/kernel/debug/dispdbg/start

To turn on (I've been using 1080p60 in h3disp):

echo "switch" > /sys/kernel/debug/dispdbg/command
echo "disp" > /sys/kernel/debug/dispdbg/name
echo "4 10" > /sys/kernel/debug/dispdbg/param
echo "1" > /sys/kernel/debug/dispdbg/start

I tried

  • reboot
  • OPi One hot unplug/plug
  • unplug/plug HDMI cable from monitor
  • unplug/plug monitor power
  • used h3disp -m 1080p60 once again and reboot

 

Interesting enough "cat /sys/kernel/debug/dispdbg/param" outputs only "4"...

 

Link to post
Share on other sites

You want to say that you can't get image on screen back? Not even after reboot? That would indicate broken script.bin. Maybe you can try that on fresh installation on spare card?

 

Mentioned metod works, tested by me (in the past) and someone else.

Link to post
Share on other sites

I'm not sure but this device I use can be the culprit - I put here just for future reference. Needs further testing...

https://www.aliexpress.com/item/3-Port-HDMI-Switcher-Splitter-3-input-1-Output-Box-HDMI-Selector-Switch-for-XBOX-360/32787229720.html

 

One interesting thing is: If you plug out an HDMI cable from this device, it finds a working one and switches to that one. But if I shutdown the Orange Pi, the LED stands lit and it does not switch... So HDMI output of OPi is alive somehow... I think I read about "not completely powered off" somewhere.

 

Anyway. Turning off the HDMI at hand does not turn of the LED either, so it is seen as alive on the outside devices (that is a good thing for me, as most devices start to scan inputs if current input signal got lost).

 

Link to post
Share on other sites

On 13/06/2017 at 11:11 PM, bozden said:

One interesting thing is: If you plug out an HDMI cable from this device, it finds a working one and switches to that one. But if I shutdown the Orange Pi, the LED stands lit and it does not switch... So HDMI output of OPi is alive somehow... I think I read about "not completely powered off" somewhere.

Hi

Yes HDMI is tricky and the way OS's try to deal with it too.

I have a Windows 10 device connected to my TV each time I switch off the TV the sound of

W10 goes back to analog and never comes back.:)

Link to post
Share on other sites

OK, I had this working for a while now... One thing left. I don't know where it comes from (this is Orange Pi One Armbian 5.31 Legacy Ubuntu Desktop now):

 

When a GPIO button is pressed (a C interrupt handler routine) I show an image, call system shutdown and turn off the HDMI as suggested. All execute fine for a while.

 

After 10 seconds or so, HDMI becomes enabled as my application auto-starts again. Then it terminates, desktop shown for a short while, drops to login prompt and does shut down correctly.

 

It is as if the X autologin user is executed during shutdown. What can be the reason of this behavior? Where can I check it?

 

Another thing I recognized is the green LED on the boards keep lit after shutdown. I don't know when this started, it is in a kind of case (cat-safe :) ). Any idea why?

 

Link to post
Share on other sites

Guest
This topic is now closed to further replies.
 Share

1 1