DMX out on Raspberry PI

[lotusvball]

My raspberry pi recognizes the DMX USB cable but I can not get it to send out DMX signals. It recognizes it as FT232R USB UART (S/N: A9K0MN3Q). I tried a windows system with QLC+ and it works fine but I can not get it to work on the raspberry PI. Does anyone have any ideas. I have attached a screenshot of the Input Screen on the Raspberry PI.

[Frank]

Hi Stephen

Strange! I use the same interface and it works great (for years) ...

I like to help, but I do not know yet where to start ...

Frank

[mcallegari]

If you're using the latest version, it might be necessary to decrease the output frequency to a value between 30 and 40 Hz.
Access from the DMX USB plugin configuration dialog.

[lotusvball]

I am not at my system but is that accessed by double clicking on the plugin?

[mcallegari]

Yes

[Frank]

Hi Stephen,

I took a "screen shot" (by the phone) of my Pi 7" touchscreen and attached it.

One difference is that it's the Universe 1 I use.

Regards
Frank

[lotusvball]

I have tried that also. It did not make any difference.

I will try the frequency change tonight. Thanks

[Frank]

... reducing this frequency to 33 Hz was also very important (for me).

But with the original value the USB DMX interface worked anyway ... Only such a flickering was very annoying, ugly just ...

See also viewtopic.php?f=7&t=12780

Frank

[lotusvball]

Went into the configuration and there is no where to set the frequency. The details of the plugin say the frequency is at 30.

[mcallegari]

Went into the configuration and there is no where to set the frequency. The details of the plugin say the frequency is at 30.

Then you're not using the latest image 20181110

[lotusvball]

I will double check tonight which image I am using and update it if I am not. Thanks.

[lotusvball]

I did not have the newest release. I updated to the newest release and now I can change the frequency. I tried every value between 30 and 43 and still nothing. I am however able to see that the closer I get to 44 the dmx light on the dmx controller will start to blink rapidly, which is supposed to mean that a dmx single is being received. However still no light activation. This works on my windows system. Is there something I am doing wrong. I did not restart it each time I changed the frequency.

Thanks so much.

[Frank]

Hi,

only one additional question:
do you use version 4.12.0 on the Windows (10) PC ...

See also the following thread:

viewtopic.php?f=33&t=12867

Greetings
Frank

[lotusvball]

Yes. I am using 4.12.0 on windows. (DMX out works on my windows system)

Thanks for the link. I will read into it and try some more testing tonight.

[lotusvball]

Still no luck with this. Any other ideas?

More info for you.

I am using this: https://smile.amazon.com/gp/product/B01 ... UTF8&psc=1

to connect to the pi and this: https://smile.amazon.com/gp/product/B00 ... UTF8&psc=1

[Frank]

Hi lotusvball,

please excuse me if I confuse something ...

Two "important" questions:

First: do you use the same components on the Windows PC as on the Raspi?

Second: how do you connect the two components together? Directly using (simple) wires?

As far as I know, you need a (special) driver chip (hardware, such as MAX481) to convert the RS-485 signals to DMX ...

I have a sample link that explains that a bit: https://electronics.stackexchange.com/q ... with-rs485

Bye for now
Frank

[lotusvball]

Yes I use the same components for both Windows and Raspberry PI. I just plug it into the usb port.

Here is how I connect the pi to the dmx decoder: https://stevenbreuls.com/2013/05/diy-us ... -under-10/

[Frank]

... there are some tips and fixes (below the article) described, which suggest that this circuit does not always (reliably) work!

For example, the power supply from the Raspi might not be enough to operate the circuit reliably ...!

[lotusvball]

I am going to try the powered hub as soon as it arrives. Will let you know after I do. Thanks.

[Frank]

This would be my first choice too!