Forked by Nathan^2

• dims more smoothly and uses xprintidle for detecting idleness
• systemd timer used to run at boot
• Regarding the touch screen, the device disables it after dimming the screen. Then, when the user taps on the screen, it brightens the screen and enables the touch screen inputs. This way, we avoid propagating the mouse inputs when we can't see the screen. (which was an issue in the original repo)

• Con/Pro: The program disables energy star mode so that it can pick up touch events throughout the night.(This feature wasn't in the original repo)
• Con: A new issue is that when the user drags, xprintidle cannot detect it.

Requirements

install these packages:

sudo apt-get install libpcre3 libpcre3-dev xprintidle

Running

Simply type in the terminal of the project's directory:

make
sudo ./timeout 30 event0

where the 30 is 30 seconds of idleness

Systemd file setup for running script at boot:

Enter into a terminal:

sudo systemctl edit --full backlight_dimmer.service

Enter the following into the new file:

Note: Change the ExecStart to your location of the timeout script

[Unit]
Description=Used to dim the raspberry pi's backlight upon idleness

[Service]
ExecStartPre=/bin/sleep 11  # sleep time of 11 seconds
ExecStart=/home/pi/Documents/Github/myForks/backlight_dimmer/timeout 30 event0
Environment=DISPLAY=:0

[Install]
WantedBy=multi-user.target

Then start it!

sudo systemctl daemon-reload
sudo systemctl restart backlight_dimmer.service
sudo systemctl enable backlight_dimmer.service

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Backlight dimmer

Leaving the backlight on the Official Raspberry Pi touchscreen can quickly wear it out. If you have a use that requires the pi to be on all the time, but does not require the display on all the time, then turning off the backlight while not in use can dramatically increase the life of the backlight.

Backlight dimmer will transparently dim the display backlight after there has been no input for a specifed timeout, independent of anything using the display at the moment. It will then turn the touchscreen back on when input is received. The timeout period is set by a command-line argument.

Note: This does not stop the event from getting to whatever is running on the display. Whatever is running will still receive an event, even if the display is off. Fixed in this Fork

The program will use a linux event device like /dev/input/event0 to receive events from the touchscreen, keyboard, mouse, etc., and /sys/class/backlight/rpi-backlight/brightness to dim the backlight. The event device is a command-line parameter without the /dev/input/ path specification.

© Copyright 2019, Dougie Lawson, all rights reserved. © Copyright 2020, Nathan Ramanathan, all rights reserved.