Hi,
I'm testing my DMX512 RGB dimmer with QLC+4.5.1 (WINDOWS 7x 64) + FT232-USB-DMX512 and I noticed strange LED flickering during fading.
After small investigation I made DMX512 stream logger and it logged that steps during fading are not equal.
Here is a one DMX512 channel values that are sent by QLC+ during chaser with 1 second fade up (0-255) and one second fade down (255-0):
0, 5, 15, 25, 30, 40, 51, 56, 66, 76,
86, 91, 102, 112, 117, 127, 137, 142, 153, 163,
173, 178, 188, 198, 204, 214, 224, 229, 239, 249,
250, 245, 235, 225, 220, 210, 199, 194, 184, 174,
164, 159, 148, 138, 133, 123, 113, 108, 97, 87,
77, 72, 62, 51, 46, 36, 26, 21, 11, 0
Total: 60 values (2s @ 30FPS)
Steps has different values (5-11) which makes LEDs flickering.
I can make averaging by software but I have to got almost equal steps...
I set highest priority for QLC+ in Task Manager but it didn't help.
Did you noticed the same behavior ?
(Sorry for my bad English...)
Best Regards,
Dawid Skalski
Not equal steps during fading
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Jano Svitok
Hi,
I'm not at computer currently, I'm just speculating:
255/30 = ~ 8, and your steps are mostly 5, 10 and 11.
My guess: QLC+ engine runs at 50 Hz (the default) and USB DMX thread runs
at 30 Hz (also the default). Therefore, not all steps are written to output.
Try to set QLC+ engine to 30 Hz - see online help advanced settings/parameter tuning.
If it doesn't help, try e.g. 60 or 90 or make your guess
Please tell us the result.
Note: as I said this is pure speculation, I didn't try anything of it.
I'm not at computer currently, I'm just speculating:
255/30 = ~ 8, and your steps are mostly 5, 10 and 11.
My guess: QLC+ engine runs at 50 Hz (the default) and USB DMX thread runs
at 30 Hz (also the default). Therefore, not all steps are written to output.
Try to set QLC+ engine to 30 Hz - see online help advanced settings/parameter tuning.
If it doesn't help, try e.g. 60 or 90 or make your guess
Please tell us the result.
Note: as I said this is pure speculation, I didn't try anything of it.
-
Dawid Skalski
Hi,
You are right! Thanks!
Master timer is 50Hz and DMX frame rate is 30Hz - it's the main problem with LEDs flickering - this frequencies makes "interference".
Because master timer frequency is hardcoded I decided to change DMX frame frequency to 25Hz through regedit (enttecdmxusbopen/frequency).
Now steps are nearly equal (10-11) and I can make "microstepping" inside my RGB dimmer.
I suggest add to new version of QLC+ advanced parameters (easily configured) like:
1) frequency of master timer,
2) number of DMX channels in DMX frame - e.g. 256 instead 512 -> then DMX will be able to send 50FPS.
Best Regards,
Dawid Skalski
You are right! Thanks!
Master timer is 50Hz and DMX frame rate is 30Hz - it's the main problem with LEDs flickering - this frequencies makes "interference".
Because master timer frequency is hardcoded I decided to change DMX frame frequency to 25Hz through regedit (enttecdmxusbopen/frequency).
Now steps are nearly equal (10-11) and I can make "microstepping" inside my RGB dimmer.
I suggest add to new version of QLC+ advanced parameters (easily configured) like:
1) frequency of master timer,
2) number of DMX channels in DMX frame - e.g. 256 instead 512 -> then DMX will be able to send 50FPS.
Best Regards,
Dawid Skalski
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Dawid Skalski
Hi,
Thanks! Now it works pretty good!
I changed DMX frame frequency to 35. I was trying with 40 but its too high.
I also changed master timer frequency to 200Hz.
LED flickering is much less.
I someone wants to tune QLC+ under Windows please use this REG file.
Thanks! Now it works pretty good!
I changed DMX frame frequency to 35. I was trying with 40 but its too high.
I also changed master timer frequency to 200Hz.
LED flickering is much less.
I someone wants to tune QLC+ under Windows please use this REG file.
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NarG
Hi it also would be good to have some setting to change number of channels in DMX universe, if number of channels is changed to 256 the frequency of dmx would increase to 60Hz because it would not need to send data to 512 channels.
There is any way to do this ? even changing source at the moment.
There is any way to do this ? even changing source at the moment.
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Matthew Marks
That might also allow the use of crummy FTDI serial dongles without or with less flicker (if the frame rate were kept the same). I imagine it might take a lot of implementing though. 
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NarG
qlcplus / plugins / dmxusb / src / enttecdmxusbopen.cpp
I think it is on line 44
, m_universe(QByteArray(513, 0))
There also is a reference in: line 32
define DMX_CHANNELS 512
But this constanct is not used
It would be easier to make it read channel numbers from registry too... I Think
I think it is on line 44
, m_universe(QByteArray(513, 0))
There also is a reference in: line 32
define DMX_CHANNELS 512
But this constanct is not used
It would be easier to make it read channel numbers from registry too... I Think
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Massimo Callegari
NarG, this is already implemented in 4.7.0. For example if you use 10 channels on a universe, the ArtNet plugin will send just those on the network.
There is only one exception: DMX USB open !
Those genious at ENTTEC defined a protocol that requires all 512 channels to be sent continuously
There is only one exception: DMX USB open !
Those genious at ENTTEC defined a protocol that requires all 512 channels to be sent continuously
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NarG
Hi.
Its strange because I used arduino and I set only thr changed values in each channel and it worked. But it is in arduino without pc
Then if its sent continiously why not reduce the number of channels to reduce the flicker problems...
Of what i know its sent by ttl to rs485 chip yhe adrrss and its value. Dimmers itselfs keep the value in memory until the next defenition
Best regarfs
Its strange because I used arduino and I set only thr changed values in each channel and it worked. But it is in arduino without pc
Then if its sent continiously why not reduce the number of channels to reduce the flicker problems...
Of what i know its sent by ttl to rs485 chip yhe adrrss and its value. Dimmers itselfs keep the value in memory until the next defenition
Best regarfs
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NarG
Can you explain me how to compile the ENTTEC dll just for test porposes, I will keep you in line with modifications
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Massimo Callegari
https://github.com/mcallegari/qlcplus/w ... uild-HOWTO
Use Qt 4.8.5 and MinGW with GCC 4.4 or 4.6 (not 4.8)
Good luck with that
Use Qt 4.8.5 and MinGW with GCC 4.4 or 4.6 (not 4.8)
Good luck with that
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NarG
I have maded a pull request, but i have not tested it on working but it compiles well, tonight I'll gonna test If anyone can test and see the implementation it will be good