Hello, I use WaveShare 7" LCD screen with HDMI + USB touch output:
https://www.waveshare.com/70h-1024600.htm
it is 1024x600 with 60Hz refresh rate.
Here is my Rock Pi4B+ information: (I did sudo apt-get update && upgrade)
Operating System: Debian GNU/Linux 10 (buster)
Kernel: Linux 5.10.131-2-rockchip-g8802564cbf09
Architecture: arm64
When I connect, I see black screen.
I tried to connect this screen to a Windows PC, it works great.
I tried to connect the RockPi4 to a large HDMI screen, works fine.
Here is the Xrandr output I tried:
root@rockpi-4b:/home/rock# cvt 1024 600 60
1024x600 59.85 Hz (CVT) hsync: 37.35 kHz; pclk: 49.00 MHz
Modeline “1024x600_60.00” 49.00 1024 1072 1168 1312 600 603 613 624 -hsync +vsync
root@rockpi-4b:/home/rock# xrandr --newmode “1024x600_60.00” 49.00 1024 1072 1168 1312 600 603 613 624 -hsync +vsync
xrandr: Output HDMI-1 is not disconnected but has no modes
root@rockpi-4b:/home/rock# xrandr --addmode HDMI-1 “1024x600_60.00”
xrandr: Output HDMI-1 is not disconnected but has no modes
root@rockpi-4b:/home/rock# xrandr --output HDMI-1 --mode “1024x600_60.00”
xrandr: Configure crtc 0 failed
blank screen.
I also tried 50Hz, same result.
Any ideas?