Background Image for Dual Screen

[dbishop]

Good morning,

I'm just polishing up a build with customizations that we plan to deploy that uses dual screens. I've been able to set the background image on the primary monitor but not the secondary monitor. How do I change the background image on the second monitor?

Thanks
Dean

[aBUGSworstnightmare]

Make sure you updated/upgraded to the latest Raspbian release.
Right-click on your desktop and change the background, on which screen to show your task bar etc. from the appearance menu.

Appearance Menu

appearamce.jpg (48.68 KiB) Viewed 493 times

The example below is a 1600 x1200 pixel desktop (two Nexus 7 Gen1 modules) from my LVDS4CM3L compute module baseboard, running FKMS driver. As you can see my primary screen atm is DPI/DSI.

Extended desktop (LVDS4CM3L with two Nexus 7 displays, running FKMS driver)

desktop_dual.jpg (110.13 KiB) Viewed 493 times

[dbishop]

Thanks @aBUGSworstnightmare. I updated/upgraded and was hopeful since I see that I was behind but even after that, I don't have the two screens in Appearance Settings. What's more, I think that since I upgraded, the items on the desktop are mirrored. Not the screen, just the items. I used...hold on a tick...

Okay, now I get it. I booted a copy of Raspbian that was loaded from NOOBS and was a "complete" load and now I have the two monitors showing in Appearance Settings.

Now I just need to either determine which component(s) I need to add to by minimal load to get the screens working or clean up a complete load to remove the stuff we don't want but leave the dual monitor support.

Any idea if there's just a component/package that I need to get the dual screens working? I had followed instructions that led me to put a 60-dualscreen.conf file in place which mostly worked.

Thanks.

[jamesh]

So, are you starting with Raspbian lite, then adding stuff?

[dbishop]

Not "Raspbian Lite" but "Raspbian" from NOOBS. If I boot "Raspbian Complete", then and only then, I get the multiple monitor support.

<sigh>I'm not sure what happened. Maybe we started our build with an old version of Raspbian/NOOBS but I just booted a fresh install of Raspbian from NOOBS and the dual monitors are there.

Thanks for your time. I guess I should be happy it's working but frustrated I can't connect these dots.

Whatevs. Thanks again

[jamesh]

Glad you are now going. If you don't need the features of NOOBS, I'd stick with the standard Raspbian install - NOOBS has some overheads you probably don't need.

[dbishop]

Ah! Now I know what happened. We plan to use these as RDS terminals and the performance is considerably better using with the GL driver disabled. And that's where things broke down. When I the OpenGL driver is enabled, I get all the dual monitor features that I'm looking for but RDS suck.

I used the instructions provided by roms2000 here:
https://www.raspberrypi.org/forums/view ... p?t=249628
to get dual-screens working without the GL driver.

Okay, so back to the drawing board of, how do I set a background and not duplicate the display of the Desktop folder on the second monitor?

Thanks.

[aBUGSworstnightmare]

That example is using the legacy driver. Works fine too and if you don't need hardware acceleration a good choice as well

[dbishop]

Yep, the Legacy driver performs brilliantly but I have two nagging issues.
1) Both displays show the contents of ~/home
2) I am unable to change the background of HDMI1

I see screenshots that suggest that issue 1 is unusual and I must have something misconfigured. All of the screenshots that I've seen use the default background image so I can't tell if I'm just missing something to change the second monitor's desktop.

What have I missed?

Capture.jpg (77.03 KiB) Viewed 338 times

[aBUGSworstnightmare]

1 is normal for the legacy driver; at least i didn't figured our way to change it.

I made intense testings of the dual framebuffer beta; there it was possible to have different background images (proof is i.e. In this video https://youtu.be/HFYg63suLoM)
once the code was officially released it was no longer possible to change the background image. I've reported that issue but did not get an answer (as dual screen on the Rpi 3 is still considered as edge case).. Nevertheless, it's a problem with the dual framebuffer implementation, regardless of the HW you use the legacy driver with.

[dbishop]

Thanks, aBUGSworstnightmare. At least I know I'm not doing something wrong.
Have a great day.