While using a Raspberry Pi (RPi) connected to a monitor or TV over HDMI, you may notice that the screen will be automatically put to sleep after a certain amount of time of inactivity.
To wake the RPi it is usually enough just to move a mouse or press some key button.
But if you are connected remotely over SSH, it seem that the only thing that you can do to wake the RPi from sleep is to reboot it.
Lucky there is a way to wake the RPi and unblank the screen from a terminal by changing display power management and screen saver settings.
Cool Tip: HDMI hotplug settings on a Raspberry Pi! Read more →
Wake RPi from Sleep
😴 Wake RPi from Sleep: Actually, there’s no wake/sleep functionality in RPi, but it can blank the video device connected to the screen. When the display stops receiving a video signal, it usually goes into a sleep mode.
If you have connected to your PRi over SSH, first of all you should specify on which display you want to unblank the screen:
$ export DISPLAY=:0
To identify the display number, execute:
$ w
- sample output -
13:47:34 up 7 min, 3 users, load average: 0.17, 0.38, 0.26
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
pi tty1 - 13:39 8:03 0.15s 0.11s -bash
pi tty7 :0 ← 13:39 8:02 1.87s 0.18s /usr/bin/lxsession -s LXDE-pi -e LXDE
pi pts/0 192.168.1.31 13:40 2.00s 0.15s 0.03s w
To wake the monitor connected to your Raspberry Pi, try the commands below.
- Disable/enable display power management signaling (DPMS) features:
$ xset -dpms && xset +dpms
- Turn the screen saver off and on:
$ xset s off && xset s on
- Turn the screen blanking off and on:
$ xset s noblank && xset s blank
Cool Tip: Shutdown & reboot a Raspberry Pi safely! Read more →
You can determine the power state of the connected monitor, the values of the DPMS and screen saver parameters by using the command below:
$ xset q
- sample output -
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: 30
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
To permanently disable/enable the screen saver – use the Raspberry Pi configuration tool:
$ raspi-config
Select the “Advanced Options” and then the “Screen Blanking”:
