QLCPlus on Raspberry Pi with VNC

[tschechniker]

Hi,

i just saw there was no solution yet for vnc into the raspberry pi qlc+ instanc.

For everyone who is searching for the solution. QLC+ is based on QT and QT has a buildin VNC Server.

How to switch from HDMI to VNC?

1. ssh into your raspberry
2. edit /etc/init.d/qlcplis ( e.g.: nano /etc/init.d/qlcplus)
3. find the following:

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QLCPLUS_OPTS="-platform eglfs --nowm --web --web-auth --operate --overscan"

4. replace the line with:

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QLCPLUS_OPTS="-platform vnc --nowm --web --web-auth --operate --overscan"

5. save and close the file
6. restart qlcplus or reboot the raspberry ( systemctl restart qlcplus )


From now you can connect via VNC directly to qlcplus running on raspberry.


How someone finds this helpfull!

[Yestalgia]

Woah this is a good tip!

[GGGss]

@yestalgia, Lachie,
Can we annotate this post somewhere? This post is priceless (even for my setups)
@OP: very very verryy good catch

[Yestalgia]

@yestalgia, Lachie,
Can we annotate this post somewhere? This post is priceless (even for my setups)
@OP: very very verryy good catch

I'll add it to the docs if can you please test it?

[liebetim]

I just set this up this weekend. Thanks so much for sharing! This is awesome.

The only thing I wasn't able to figure out how to adjust the resolution. I tried editing framebuffer_width and framebuffer_height and then hdmi_group and hdmi_mode in config.txt based on other posts, but didn't have any luck. If someone happens to know how it can be adjusted to match the display of the viewer that would be appreciated.

[GGGss]

It might be necessary to set a specific screen resolution: http://elinux.org/RPiconfig#Video_mode_options

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Most likely you will have to adjust the screen resolution, with the same
instructions for a HDMI display. For example these parameters in the config.txt
file might work for you:
disable_overscan=1
hdmi_drive=1
hdmi_group=2
hdmi_mode=16
config_hdmi_boost=4

[liebetim]

I gave those a whirl along with changing some of the other config.txt options with no luck. I may have been doing something wrong.

However, I was able to get it to work by specifying a resolution in /etc/init.d/qlcplus

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QLCPLUS_OPTS="-platform vnc:size=1920x1080 --nowm --web --web-auth --operate --overscan"

Thanks to all!

[maxwell]

hey there - I am able to connect through "remote desktop connection" and see the terminal but it does not show me the gui of the open instance of qlcplus running - I am able to open a new instance of the program with "qlcplus" but typing "sudo qlcplus" gives me this error:

"Invalid MIT-MAGIC-COOKIE-1 keyqt.qpa.xcb: could not connect to display :11.0
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, xcb.

Aborted"

is there a way to view the open instance?
thanks!

[GGGss]

hey there - I am able to connect through "remote desktop connection" and see the terminal but it does not show me the gui of the open instance of qlcplus running - I am able to open a new instance of the program with "qlcplus" but typing "sudo qlcplus" gives me this error:

"Invalid MIT-MAGIC-COOKIE-1 keyqt.qpa.xcb: could not connect to display :11.0
qt.qpa.plugin: Could not load the Qt platform plugin "xcb" in "" even though it was found.
This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.

Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, xcb.

Aborted"

is there a way to view the open instance?
thanks!

And what settings do you use in /etc/init.d/qlcplus?
If you use the very latest build (versus 4.13) there are issues with the headless mode for the PI...

[fnupp]

Hi,
I justed downloaded and installed version 4.13.0 on Raspberry Pi 5 and tried to edit the file /etc/init.d/qlcplus. Found out that is is missing - did the location change with the last version?


The service is running and accessible by hdmi and web.

Thanks,
fnupp

[mcallegari]

QLC+ on the RPi is no longer a System V service, but a systemd one.
The startup script is in

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/usr/sbin/qlcplus-start.sh

[ljmichael]

thank you for your explanation

i have create a little manual

1 Download putty

2 Start it up and fill in ip(the ip from your raspberry pi)
- Default user name:pi
- Default password:raspberry

after this you type in

sudo nano /etx/init.d/qlcplus

3. find the following:

QLCPLUS_OPTS="-platform eglfs --nowm --web --web-auth --operate --overscan"

4. replace the line with:

QLCPLUS_OPTS="-platform vnc --nowm --web --web-auth --operate --overscan"

5. save and close the file (write out)

6. restart qlcplus or reboot the raspberry ( systemctl restart qlcplus )

[GGGss]

Typo?

sudo nano /etx/init.d/qlcplus

/etC/init.d/qlcplus

[mcallegari]

It's not even that.
On the latest official image, there's a script here:

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/usr/sbin/qlcplus-start.sh

[fnupp]

Thank you all for your help! Works like a charm .-)

I updated the 'manual' with the new file path and screen resolution

1 Download putty

2 Start it up and fill in ip(the ip from your raspberry pi)
- Default user name:pi
- Default password:raspberry

after this you type in

sudo nano /usr/sbin/qlcplus-start.sh

3. find the following:

QLCPLUS_OPTS="-platform eglfs --nowm --web --web-auth --operate --overscan"

4. replace the line with:
QLCPLUS_OPTS="-platform vnc --nowm --web --web-auth --operate --overscan"

or to set the resolution to a desired one
QLCPLUS_OPTS="-platform vnc:size=1920x1080 --nowm --web --web-auth --operate --overscan"

5. save and close the file (ctrl-x y)

6. restart qlcplus or reboot the raspberry ( systemctl restart qlcplus )