OpenDMX Flicker

Ken Jacobs · Sat Jan 18, 2014 7:29 am

I have an OpenDMX interface and I know from reading many forums and posts that they are known for issues with light flickering, etc. What I have found with other DMX software is the OpenDMX works fine when the number of output channels is limited....ie only sending 64-128 channels seems to solve the flickering problems.

Is there any way to limit the number of channels being sent from Q Light + so that interfaces like the OpenDMX could become usable on a limited channel basis???

Thanks.

Henry P · Sun Jan 26, 2014 6:29 pm

I also have an issue with my open dmx flickering the channels its a real pain and I wish I knew how to fix it !

Davey Daytona · Mon Jan 27, 2014 4:19 pm

Hello Ken and Henry

Here is a post that might help. I had this same problem with my uDMX interface.
https://sourceforge.net/p/qlcplus/discu ... e3b5/#9129

Ken Jacobs · Sun Mar 16, 2014 9:37 pm

I just came back to find some replies to this thread....LOL. Thanks for the info, but I am not sure my system suffers quite the same as others. I have not been using LED lights, just standard theater lighting cans. When the system sits with all lights on, I get intermittent flickering of the lights. No fading, just full on. I thought it might be some form of local interference, but then had the same problem at a completely different location, with a different set of lights.

The next step was to try a different program that only outputs 64 channels, instead of the full 512. I had NO flickering problem at all once I dropped the channel count.

Also, I am using the linux version of QLC+ and am not sure how I would adjust the master timing to experiment as described in the article.....any other thoughts?

Ken

Matthew Marks · Sun Mar 16, 2014 11:43 pm

Ken, I'm pretty sure it's fundamental failing of these cheap interfaces, which are just serial converters which don't even have a buffer big enough to hold one DMX frame, so require timely feeding of bytes from the CPU or partial frames will be transmitted. Even with a lightly-loaded computer, task scheduling is not designed to guarantee such processor availability, and things like moving the mouse can cause the output to break. Spend £20 or your local currency equivalent on an Anyma-compatible DMX interface from Greater China on eBay. They will ensure that only valid frames are created, however busy the CPU.

Matthew Marks · Sun Mar 16, 2014 11:47 pm

I talked about the above converter here: https://sourceforge.net/p/qlcplus/discu ... /0fa9fb2b/

Ken Jacobs · Tue Mar 18, 2014 3:31 am

Thanks for the info Matthew.....my interface is indeed a serial converter style copy. I went to ebay to have a look....I assume any uDMX compatible interface is a Anyma interface, based on what I have read????

Matthew Marks · Tue Mar 18, 2014 9:46 am

Yes, as far as I understand it. I graduated from a cheap serial converter to a cheap one of these and haven't looked back.