Switch off display background light

  • Is there any possibility to switch off the background light of the display? This should happen during night time, but still with a touch on the touch screen the touch must be recognized and the light should be switched on again.

  • Hi,


    if you have connected the display to the backlight PWM then you should be able to setup the brightness. You can change it from display off to fully brightness. There is a driver which handle this. It´s located under

    Code
    1. cd /sys/class/backlight/


    So in my opinion you can create a time-controlled program by your own, which are controlls the backlight and also recognize the touch. I´m not sure if there is any driver which can handle that for you. Maybe there are programs which helps you to implement that (e.g. Cron).


    Your F&S Support Team

    F&S Elektronik Systeme GmbH
    As this is an international forum, please try to post in English.
    Da dies ein internationales Forum ist, bitten wir darum, Beiträge möglichst in Englisch zu verfassen.

  • By default, i.e. on the (text) console, automatic blanking actually *is* active. The console will be blanked after 10 minutes of inactivity and will be switched on again by a mouse movement or an arbitrary key. (The key has to come from a connected keyboard, sending a character from the terminal program through the serial line does of course not trigger unblanking).


    So it is actually the result of the GUI if screen-blanking is switched off. Then it is also the job of the GUI to switch it back on. Qt has appropriate settings, X11 has the x11screensaver, other GUIs should have similar functions for screensavers, too.


    Your F&S Support Team

    F&S Elektronik Systeme GmbH
    As this is an international forum, please try to post in English.
    Da dies ein internationales Forum ist, bitten wir darum, Beiträge möglichst in Englisch zu verfassen.

  • Hi,


    we don´t have an own documentation about the backlight driver. We are using the default backlight driver from drivers/video/pwm_bl.c of the kernel (nothing special). The default documentation of the backlight driver is located in the Kernel directory: Documentation/ABI/stable/sysfs-class-backlight.


    I can not tell how to control backlight using Chromium but the kernel provide the default interface for backlight driver. So Chromium must just use the default backlight interface (if supported in Chormium). In my opinion it is a Chromium specific setup.


    Your F&S Support Team

    F&S Elektronik Systeme GmbH
    As this is an international forum, please try to post in English.
    Da dies ein internationales Forum ist, bitten wir darum, Beiträge möglichst in Englisch zu verfassen.