monitor-brightness-cron

A script that sets monitor brightness based on the time of day

Prerequisites

Relies on having ddcutil, Python 3 and sh installed.

Example Cron

# run every 5 minutes
*/5 * * * * <some path>/monitor-brightness-cron/monitor_brightness.py 2>&1 | logger -t monitor_brightness

Raspberry Pi

Say you have a monitor that supports DisplayPort and it doesn't support DDC over it, but does have a HDMI port which supports DDC. One solution is to attach a Raspberry Pi to the HDMI port permanently for the sole purpose of running this script while you continue to use DisplayPort for video.

/boot/config.txt:

[pi4]
dtoverlay=vc4-kms-v3d

[all]
dtoverlay=vc4-kms-v3d

(note these are not set to vc4-fkms-v3d, the f is absent)

sudo apt-get update
sudo apt-get upgrade -y
sudo apt-get install -y git python3-venv pipx ddcutil
pipx install --spec git+https://github.com/aarongorka/monitor-brightness-cron.git monitor-brightness-cron

Set your timezone appropriately:

sudo timedatectl set-timezone 'Australia/Sydney'

Ensure the i2c_dev kernel module is loaded:

echo i2c_dev | sudo tee -a /etc/modules
sudo modprobe i2c_dev