Change HDMI monitor brightness (aka backlight) from OSMC/Kodi

Hi, I’m wondering if it’s possible to control the brightness of an external monitor directly from OSMC/Kodi?

Note that I’m talking about sending commands to the monitor via an HDMI cable, to control the monitor’s backlight setting. This is distinct from simply changing the way the screen images are rendered to make them appear dimmer.

I know it’s theoretically possible to control monitors by sending commands via the HDMI interface, but I haven’t seen any way to do that from Kodi/OSMC. My system is running on a Raspberry Pi 3, but if a solution exists, I hope it would be applicable to many platforms.

The raspberry pi hardware is not capable of this as far as I can tell. I’ve seen no operating system on the pi platform that can.

That’s a shame. Are there any other platforms that do support this?

Refusing to take no far an answer, and after a lot of Googling and experimentation, I’ve found a way to do what I asked. I’ll post it here for reference, for anyone trying the same thing. Most of it is from http://www.ddcutil.com/raspberry.

Anyone wishing to try, be aware it comes with a safety warning and by some accounts meddling with these settings CAN BREAK YOUR MONITOR OR YOUR OSMC INSTALLATION. Do your own research, you’ve been warned. That said, the following worked for my Raspberry Pi 3 and newish Samsung monitor.

Log in to your OSMC Raspberry for a command prompt and type:
sudo nano /etc/apt/sources.list
Add the line:
deb http://ftp.debian.org/debian testing non-free contrib main
And save.

Then:
sudo apt-get update
sudo apt-get install ddcutil
Agree to install all dependencies.

Then:
sudo nano /boot/config.txt
Add the line:
dtparam=i2c2_iknowwhatimdoing
And save.

Then:
sudo nano /etc/modules
Add the line:
i2c-dev
And save.

Reboot.

Then try using ddcutil. First to report monitors:
sudo ddcutil detect
Then to report brightness:
sudo ddcutil getvcp 10
Then to set brightness:
sudo ddcutil setvcp 10 50
(50 being the brightness setting from 0-100)

For me at least, this worked. Now I have to link these commands to Kodi menus (any advice about this appreciated). Good luck!

— EDIT —
I’d also recommend the following command to allow the osmc user to run the command without sudo:
sudo usermod -G i2c -a osmc
Also there’s more info in this Kodi forum thread about how to make it work using keyboard shortcuts:
https://forum.kodi.tv/showthread.php?tid=338523

1 Like

Nice find! Thanks for sharing

Has anyone been successful installing/configuring/using ddcutil on Vero 4k?
Picture is by all standards fine, which is a bit too dark in dark areas and too white in white areas for my taste.

You can tweak AMCsc settings for this purpose, but did you try adjusting in Kodi first?

Sam

As soon as I get the Vero I will be willing to play around with “AMCsc”… eager to do so.
Can you point me to more detail how to deal with AMCsc?
From what I remember, there are no desired options inside KODI.

Cheers

CSC is colour space correction. You can change the brightness on the device but I’m not sure you can signal the monitor