Adjust Screen resolution


#1

I have setup x11vnc on the RockPi4B (debian), without any monitor connected.
The screen resolution is very small 800x480 pixel. :frowning:

xrandr shows:
Screen 0: minimum 320 x 200, current 800 x 480, maximum 8192 x 8192
HDMI-1 disconnected primary (normal left inverted right x axis y axis)
DSI-1 connected 800x480+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
800x480 61.88

“cat /sys/class/drm/card0-HDMI-A-1/modes” is empty

How can I acitavte HDMI and/or set the resolution?


#2

Because there is no HDMI, the resolution by default is MIPI, the Raspberry Pi display…

You can try to set the resolution with following command:

xrandr --output HDMI-1 --mode 1920x1080 --refresh 60


#3

Hi Jack,
doing this brings the following error message: “xrandr: cannot find mode 1920x1080”

I tried the following flow:
cvt 1024 768 60

1024x768 59.92 Hz (CVT 0.79M3) hsync: 47.82 kHz; pclk: 63.50 MHz

Modeline “1024x768_60.00” 63.50 1024 1072 1176 1328 768 771 775 798 -hsync +vsync

sudo xrandr --newmode “1024x768_60.00” 63.50 1024 1072 1176 1328 768 771 775 798 -hsync +vsync
sudo xrandr --addmode DSI-1 “1024x768_60.00”
sudo xrandr --output DSI-1 --mode “1024x768_60.00”

However,from the raspberry Pi I know this needs to be adjusted in /boot/config.txt. However there is no config.txt in the RockPi Debian.