I’m using VVVV to control a line of LEDs, sweeping a white square horizontally across the renderer which is then sent to a Video Micro Converter and converted to E:Pix (DMX). The LEDs should show a very fast stream of light going from right to left.
Even at speeds of only 7Hz (period of 0.14 on the LFO) , gaps appear between the LEDs which shows something in the signal chain isn’t keeping up/frames are being dropped. I’d like to get up to speeds of 20Hz, but this is not possible, as the signal becomes more and more broken.
i assume that you have a hardware problem.
did you try another DVI source?
how many leds do you control? maybe it’s better to create DMX with vvvv itself.
anyway it may be worth a try to play around with renderer’s “hidden” parameters. maybe you have to change the refresh rate or presentation interval? but honestly i don’t think so
OK, the initial post was more to do with debugging the actual problem. Here’s the patch.
What we’re actually trying to do is sweep a picture over a vertical line of LED Pixels about 20 times per second. This would be a period of 0.05s on the LFO, but once we get down past 0.3s we start seeing the stream break up (it’s easier to see horizontally, that’s why I asked about that first) on the LEDs, and on the computer monitor as well.
We’ve increased the rate of the DMX-Signal (we’re actually using E:Pix which has more DMX channels and is faster)which improved the situation, but we still can’t get as fast as we want.
Kalle: There are 60 LEDs in a line, and sending DMX from vvvv direct didn’t help. We’ve also tried changing the renderer’s parameters to no avail.
karistouf: I couldn’t get my head around the pipet EX9, but it seems it’s only representing one pixel at a time? How do you output a 80x60 Pixel picture with that?
The patch is really simple, but something is causing the signal to lag. Any help much appreciated! Thanks kalle and karistouf already!
OK I update the graphic card driver, and set it to 75Hz instead of 60Hz. Gained a bit of speed, which produced better results - but not good enough! ;)
The LEDs should be fine, they came straight from Traxon (60 Pixel Tube). They’re controlled with e:pix (a faster, higher channel version of DMX).
I’ll try to set up the patch with pipet instead of the renderer and see how that goes.
