Turn off screen blanking in Raspberry PI OS

One of the little things that I like to have control over after setting up a clean raspberry PI OS image is to turn off, or at least have control over screen blanking. That is after a few minutes of leaving the raspberry pi alone the screen will go blank rather than continuing to display whats going on. There are many use case examples of using a Raspberry pi to run some kind of application where I would like the output to continue to be displayed on a monitor without me having to move the mouse or touch the keyboard.

The reason why the screen blanking happens is because screen saver settings cause the screen to go blank after a few minutes by default, but there is not software installed to easily control these settings by default. So in this post I will be going over some options for having control over this including th use of the linux xset command.

1 - Uisng xset to just turn off screen blanking right now

So if I want to just turn off the screen blanking right now, and not necessarily make the changes permanent each time I reboot the pi then I can just use the xset command. In fact all settings that I change with just xset will be set back to default when I log out, or rebut the pi. However what is nice about this is that I can just turn it off for not without installing any additional front ends, or digging though any kind of configuration files as the xset command should be there to work with to begin with in a clan Raspberry PI OS install.

1.1 - Using xset q to query what the current status is with screen saver settings

So the xset command can be used to query what the current state of affairs is with X11 screen saver settings by just calling the xset command followed by the q option.

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$ xset q
Keyboard Control:
auto repeat: on key click percent: 0 LED mask: 00000000
XKB indicators:
00: Caps Lock: off 01: Num Lock: off 02: Scroll Lock: off
03: Compose: off 04: Kana: off 05: Sleep: off
06: Suspend: off 07: Mute: off 08: Misc: off
09: Mail: off 10: Charging: off 11: Shift Lock: off
12: Group 2: off 13: Mouse Keys: off
auto repeat delay: 500 repeat rate: 33
auto repeating keys: 00ffffffdffffbbf
fadfffefffedffff
9fffffffffffffff
fff7ffffffffffff
bell percent: 50 bell pitch: 400 bell duration: 100
Pointer Control:
acceleration: 20/10 threshold: 10
Screen Saver:
prefer blanking: yes allow exposures: yes
timeout: 600 cycle: 600
Colors:
default colormap: 0x20 BlackPixel: 0x0 WhitePixel: 0xffffff
Font Path:
built-ins
DPMS (Energy Star):
Standby: 600 Suspend: 600 Off: 600
DPMS is Enabled
Monitor is On

1.2 The xset -dpms and s options

So the two xset options of interest in the man page here are -dpms that will disable DPMS, and the s option that can be used to set values for the screen saver. There are several values that can be used for the s option, but one of them is simply off that will work just fine if I just want to turn the screen blanking off.

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$ xset -dpms
$ xset s off

Now lets to another querry and see what changed.

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$ xset q
Keyboard Control:
auto repeat: on key click percent: 0 LED mask: 00000000
XKB indicators:
00: Caps Lock: off 01: Num Lock: off 02: Scroll Lock: off
03: Compose: off 04: Kana: off 05: Sleep: off
06: Suspend: off 07: Mute: off 08: Misc: off
09: Mail: off 10: Charging: off 11: Shift Lock: off
12: Group 2: off 13: Mouse Keys: off
auto repeat delay: 500 repeat rate: 33
auto repeating keys: 00ffffffdffffbbf
fadfffefffedffff
9fffffffffffffff
fff7ffffffffffff
bell percent: 50 bell pitch: 400 bell duration: 100
Pointer Control:
acceleration: 20/10 threshold: 10
Screen Saver:
prefer blanking: yes allow exposures: yes
timeout: 0 cycle: 600
Colors:
default colormap: 0x20 BlackPixel: 0x0 WhitePixel: 0xffffff
Font Path:
built-ins
DPMS (Energy Star):
Standby: 600 Suspend: 600 Off: 600
DPMS is Disabled

So yes not DPMS is disabled, and the timeout for the screen saver is now zero.

2 - So then there is trying xscreensaver

In Raspberry Pi OS the package xscreensaver is not installed by default. This package alone is the most basic striped down package for screen savers. This package alone can be installed, and by doing so I will then have a graphic front end for changing screen saver settings in the preferences menu. Also changes that I make in the front end will remain after I log out or reboot.

So for starters I just need to install the package

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$ sudo apt-get install xscreensaver

Doing so will eat up about 8MB of space, and I might need to reboot to get the menu to appear in preferences. However once I can get to it I can use that to just disable the screen saver, and keep it disabled once and for all.

3 - Conclusion

So having control over this is just one of those many little things that I like to tweak and have control over when it comes to setting up a clean Raspberry PI OS install.