If you search for digital signage solution, probably will run across many different options, usually they bill monthly by device, but if you want something at no cost, just very few options will be available, one of them is Anthias, and usually free comes with limitations, you have to manage each device individually and by default there is no option to set screen resolution, it will automatically set to the maximum your monitor support, but where there is a will, there is a way.
I tested it with a Raspberry PI 4 and Raspberry PI 5, I did the manual installation deploying Debian 12 (Bookworm) and then on top of it installing the Anthias solution, be sure to use same version, the solution I found on this forum, read there for more details.
Force HDMI-0 and HDMI-1 to 1920×1080@60
1) Confirm connector names
ls -1 /sys/class/drm | grep -E 'HDMI|DSI|eDP'
cat /sys/class/drm/card1-HDMI-A-1/status
cat /sys/class/drm/card1-HDMI-A-2/status
# (generic)
cat /sys/class/drm/card*-HDMI-A-*/status2) Force 1920×1080@60 from boot (recommended)
Edit cmdline.txt — it’s one single line:
sudo nano /boot/firmware/cmdline.txtAppend at the end (precede with a space):
video=HDMI-A-1:1920x1080@60 video=HDMI-A-2:1920x1080@60Reboot:
sudo rebootVerify after boot:
cat /proc/cmdline | tr ' ' '\n' | grep ^video=
cat /sys/class/drm/card1-HDMI-A-1/modes
cat /sys/class/drm/card1-HDMI-A-2/modesAfter that, the screen resolution will be set to Full HD.
