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Rotate display only for one video output?

Posted: Mon Jul 18, 2016 12:40 am
by Charon
Hey Guys,

due to the fact that I have to rotate my screen 180° for the composite TFT, I wanted to ask you whether anybody knows a possibility to rotate only the signal for the composite output but not for the hdmi?

I've set the "display_rotate = 2" in the config.txt and if I connect my raspberry pi zero to a TV via HDMI, the picture there is also upside down :|

(If there is no option for the config.txt file, I have to check for the possibility to script any thing on my own)

Re: Rotate display only for one video output?

Posted: Mon Jul 18, 2016 4:44 am
by kite
You will have to write a script that will update that entry in file and reboot the Pi.. the Composite and HDMI share the same display buffer, therefore any change to the buffer affects both! Using DPI mode acts as a separate buffer (project I am working on, appears the only way to satisfy both requirements) but that isn't composite so you're only option is scripting :)

Re: Rotate display only for one video output?

Posted: Mon Jul 18, 2016 7:13 am
by Ganreizu
If you have the high resolution screen that cannikin and I have there's a setting in the screen menu that does it through the board itself, so it'll flip the screen for composite but not HDMI. Otherwise you would have to use the EDID tag in config settings and grab the EDID handle for every HDMI screen you intend to connect to.

Re: Rotate display only for one video output?

Posted: Mon Jul 18, 2016 12:07 pm
by Charon
kite wrote:Y the Composite and HDMI share the same display buffer, therefore any change to the buffer affects both! Using DPI mode acts as a separate buffer (project I am working on, appears the only way to satisfy both requirements) but that isn't composite so you're only option is scripting :)
Thank you for that information (d'oh next project I will send back my TFT as long a I got one which will fit the normal way :D )
If you have the high resolution screen that cannikin and I have there's a setting in the screen menu that does it through the board itself, so it'll flip the screen for composite but not HDMI. Otherwise you would have to use the EDID tag in config settings and grab the EDID handle for every HDMI screen you intend to connect to.
Thanks for this input, but my dump display doesn't have any option like that. But thanks for pointing me on the EDID tag.