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Testing DMX output on GPIO and UART line

Posted: Wed Jul 20, 2022 7:59 pm
by Jackson75
Hi all,
New to this forum. Amazing software the QLC+
I am playing around with a Raspberry Pi 4 and trying to output dmx data on GPIO lines and also UART TX line.
It seems I don't get anything out according to my scope.
Should I need to do more than just selecting the output settings in the input/output tab in order to get the data going?
Thanks in advance!

Re: Testing DMX output on GPIO and UART line

Posted: Thu Jul 21, 2022 7:07 am
by mcallegari
Hi, not every GPIO on the Pi is the same.
Many pins have different meanings and their configuration is done outside QLC+.

As for UART, it should work out of the box.

See also this for reference: viewtopic.php?f=17&t=8894

Re: Testing DMX output on GPIO and UART line

Posted: Thu Jul 21, 2022 9:52 am
by Jackson75
Ah thanks, by looking at the ref page it seems I have to edit the config file to change direction of TX.. probably that’s the issue.

BTW - is there a way to edit the Pi config’s inside Pi or do I have to edit the image and write it all back to SD ?

Re: Testing DMX output on GPIO and UART line

Posted: Thu Jul 21, 2022 2:46 pm
by mcallegari
You can access the Pi via SSH, as written in the provided PDF

Re: Testing DMX output on GPIO and UART line

Posted: Fri Jul 22, 2022 1:15 pm
by Jackson75
I think SSH will be more advanced than my hardware brain can take :)
It's possible to edit the QLC+ image in Windows and then write it back to SD? (Format and write)

I was not able to get UART TX to output DMX. I tried to find where to paste the below:
echo 18 > /sys/class/gpio/export
echo out > /sys/class/gpio/gpio18/direction
echo 1 > /sys/class/gpio/gpio18/value

But I could not find the file you were referring to: /etc/init.d/qlcplus file

Can you please explain where to edit and get the UART TX output enabled ?
Thanks

Re: Testing DMX output on GPIO and UART line

Posted: Sat Jul 23, 2022 2:15 pm
by mcallegari
Windows doesn't read Linux partitions (ext2/3/4 format)
You need a proper tool for that like
https://sourceforge.net/projects/ext2read/
or
https://www.diskinternals.com/linux-reader/

Re: Testing DMX output on GPIO and UART line

Posted: Wed Jul 27, 2022 11:14 am
by Jackson75
OK
So when using the suggested linux apps I can open the SD card in a PC and edit the needed files ?