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xLightsSequencer / xLights

xLights is a sequencer for Lights. xLights has usb and E1.31 drivers. You can create sequences in this object oriented program. You can create playlists, schedule them, test your hardware, convert between different sequencers.
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FTDI USB DMX adapter: flickering lights #3484

Open keukenrol opened 1 year ago

keukenrol commented 1 year ago

NOTE: IF YOU DO NOT ATTACH A SEQUENCE THAT DEMONSTRATES YOUR PROBLEM THEN THERE IS A HIGH PROBABILITY YOUR ISSUE WILL JUST BE CLOSED AND NOT INVESTIGATED.

Describe the bug When outputting DMX via the FTDI usb adapter, the light fixtures strobe / flicker randomly. Random colors appear as well on different fixtures.

To Reproduce Steps to reproduce the behavior: (and/or link to a short video showing the problem with audio track describing what you are doing) Use an FTDI USM DMX dongle (the cheapest dongles available, often identifying as FT232R), define a dmx fixture with at least a brightness and a color channel and use the dmx test function to check its output. While the colors are rendered correctly, it flashes randomly (thus no strobe function is activated)!

Expected behavior Stable DMX output to fixtures

Screenshots /

Versions (please complete the following information):

Additional context A similar issue was present in the past with QLC+. The fixtures work fine with the same adapter on QLC+. They have updated the dll for libFTDI and it worked afterwards. Maybe this is a pointer to the issue? The timing has to be generated on the pc rather than in the dongle itself.

Attachments Sequences are irrelevant since they are not the root cause.

keithsw1111 commented 1 year ago

Is the DMX line terminated?

keukenrol commented 1 year ago

Yes it is. Edit: Link to video https://youtu.be/C91QUZokZ94

Using the sequencer to show the effects live using the DMX function. First channel is the dimmer, then R, G, B and W. Finally strobe to show that it is not this channel which is creating the flicker as it is at a different frequency and not random.

Used a single fixture as test with a DMX terminator plug attached to it.

keithsw1111 commented 1 year ago

If you use tools test do you still see the flicker. There is not much xLights can do wrong driving DMX lights from a locally attached DMX dongle. Is this dongle a true DMX dongle. I am not familiar with it ... maybe we dont support it although I have never seen a true DMX dongle we dont support.

Which protocol are you using DMX or OpenDMX?

keukenrol commented 1 year ago

If you use tools test do you still see the flicker. There is not much xLights can do wrong driving DMX lights from a locally attached DMX dongle. Is this dongle a true DMX dongle. I am not familiar with it ... maybe we dont support it although I have never seen a true DMX dongle we dont support.

Which protocol are you using DMX or OpenDMX?

I am using the OpenDMX protocol since it is the protocol supported by the dongles (I have 2 of them, different manufacturer and physical appearance but underneath the same thing).

Using a single fixture, the test mode works fine. With multiple I get flickering. I have noticed when using the 40fps sequence mode, flickering is all over the place. With the 20fps variant it is as good as gone.

Tried manually changeing the speed and everything at or below 30 fps is fine.

keithsw1111 commented 1 year ago

Maybe try reducing the number of DMX channels on the USB output ... maybe it just cant transmit that much data at that speed?

dnwenco commented 11 months ago

I have the exact same issue and symptoms as @keukenrol When I switch from 40FPS to 20FPS, it seems to solve the flickering. I only have 3 channels I am transmitting. Also, QLC+ functions as expected with this setup, it is only XLights that causes this flickering.

MBCoder2022 commented 4 months ago

I'm having the same issue which can be solved by the same workaround (FPS reduction to 20) but for existing 40fps-sequences this downscaling doesn't work well.

What might be interesting/helpful: I'm using the same dongle/controller config on two systems: On a PC (Win10 Pro) everything works fine, while on a notebook (Win11) the weird behaviour occurs. So it could be rather an issue related to the OS or OS/Driver-compatibility than an xlights-issue. A different tool (Freestyler) works well with both configurations.