How to patch led arrays?


how do i patch a led array in bottom left to top snake mode as a fixture in vvvv?

Does anyone tried that allready or have a sample patch? Would be great…

PS: i have a 9x18 led wall in bottom left to top snake mode. I can send with vvvv allready dmx via the artnet sender but the patch is of course wrong. I dont know where to make the dmx channel changes exactly… :(

see SwapDim (Spreads) and try to ask more precise

I’ve used pipet as a pixel mapper for LEd walls but performance is a bit shonky when you get to higher resolutions (higher than vga, or even 1/2 VGA…)
Linear spread and resample will help you here…

Are you already able to have a 9 x 18 IObox color (columns x rows), and send that to the LEDs? Like Kalle said, ask more specific questions, and show us example patches.


thanks for your replys.
I was trying allready to set the columns and rows via SwapDim. But could not get it to work.

Below is attached a snapshot of my 9x18 3ch_rgb led array patch in magicq window. You will see the head (Generic 3ch RGB led) numbers patched succesfully in magicq in left_bottom_to_top_snake_mode. What i need to know how to patch such a led array with this head order in VVVV. 1 head number means 3ch dmx (eg. number 1 = R:1 G:2 B:3, number 2 = R:4 G:5 B:6 etc.)

Also attached is a simple fft patch mapped to artnet out. Basically i need that patch to work with my 9x18 led array patched like the picture attached.
Another problem is that i can not get dx9texture correctly mapped to the pipet :(

I also wonder, if i can use VVVV as a media server with magicq to simply send the fft texture to magicq as media over artnet. In this case i think i would not need to patch the fixtures in VVVV, since they are allready patched in Magicq. This option would be great, so they would work together (magicq as master and vvvv as slave media server, serving real-time fft analysis.)

Btw kalle, catweasel & west: i was reading nearly all of your posts about artnet and dmx since 1 year. Tried so many patches from all of you and would like to thank you for all your effort to the community…

FFTdmx.v4p (31.2 kB)

in the meantime i solved the dx9texture correct pipet mapping with the help of the linearspread node. But still need to know how to patch to the dmx output. Looks like i have to do it wit the getslice node. But dont know how…

vvvv maps dmx values between 0 and 1. so no need to multiply with 255 here.

for the reason that RGB needs 3 dmxchannels per pixel you will need to set the Bin Size of the SwapDim to 3.

anyway Cons (Spreads) was the wrong choice because it would have sorted in a RRRRRGGGGGBBBBB way instead of RGBRGBRGBRGB (you know what i mean)

furthermore i wonder that you pipet only 120 pixels.

try attached patch for basic communication functionality.
if your artnet device is not reacting try to set back the destination address to (because this is an experimental parameter…)

further recommended reading:

FFTdmx.v4p (45.0 kB)

this is a major pain. while i love that vvvv norms almost everything between (0,1), with the dmx it stinks: i found a lot of dmx devices trigger certain behaviours with certain numbers.


see AsValue and AsDMX modules

Hi Kalle,

i understand now with the swapdim bin size to 3.
As you said cons is unnecessary.

What i still dont know is, how to patch the led array in left_bottom_to_top_snake_mode, because the led array is cabled like that as the picture above i posted before.

Is there a way to see the dmx channels and edit them in a channel-window after SwapDim? That way i could see in which logic SwapDim patches the dmx channels.

Attached is updated file with linearspreads.

FFTdmx_1.v4p (34.1 kB)

Yo Leddie (cool name!), look at your IObox value advanced, that you connected to the Swapdim, you use the wrong outlets. You need the pins on the bottem RIGHT not the (hidden) one on the left. (you need Y output, not X output)

Why do you start with the hard part to make it work? Forget that untestable (yet cool looking ;) ) FFT part for just a second, and lets get back to the basics.

Is the snakemode you mean in your case going from slices somthing like the attached patch?

edit: I am using Chamsys a lot for little live (non vvvv related) shows, and I am not sure how to use vvvv in the free version.

I think you can set Chamsys up and take an Input Artnet universe , and use hot takeover to the normal output (the uni with the rest of the lights). Reading the manual however it refers to this method with having 2 real consoles, so I am in doubt a bit.

Snakemodedunno.v4p (25.9 kB)

Hi West,

you are right, the FFT is just not right for testing pixel outputs, but its so lovely ;))

The correct snake mode is: 153 - 144 … 9 - 0 to 1 - 10 … 145 -154
(the third option you mentioned)

I did not understand why you set the dmx output (i mean getslice output matrix window) to 18x9, because every other settings are set to 9x18 which i need.

i tried to change values from (17 to -1) to (8 to -1) in the repeat resample node, but this looks like a total mess on the matrix window. Sometimes 2 or 3 pixels turns on etc. Could you please repatch your example to the correct snake mode 153 - 144 … 9 - 0 to 1 - 10 … 145 -154 and change the output matrix also to 9x18. In this case i would have 2 examples and can learn better by comparing 2 different setups.

Thanks very much for your time & effort. I am getting closer to this patching thing with vvvv.

“PRETEND THIS IS YOUR COOL PIPET FFT OUTPUT” . This was fun to read! hehehe

Well, I attached my final try, should work, I am patching in a different version of vvvv, so perhaps, just remove the DMX creating line and replace it with the one that worked for you before.

I went to 18 x 9, because that are the lines you will need in the end. Vvvv doesn’t see any difference between a spread that is 18x9 or 9x18, all vvvv sees is 162 slice. The columns/rows is just a luxury for us Humans ;)

Also fun to learn the Point/Repeat modes for the Resample node. I have also attached a patch with some other stuff, for your LED array.

Snakemode3.v4p (32.5 kB)
GridTest9x18.v4p (27.3 kB)


yes it works now as expected. Thank you very much!
I now understand how patching works. With your explanations i am sure i will be able to patch different arrays too.

The grid test thing is absolutely what i was looking for in vvvv ;) After my “cool” fft output, this is just like a christmas gift ;) You make my day West! Did you patch those patches yourself? They look really cool.

Is there a possibility to get in contact with you via email or skype?

You spend so much time teaching me that, thank you again.

You are welcome, yes, these are my patches, I made it for a 20x10 array, glad to read it all works now for you. We all had to learn at some point…

I got skype, not online so much, westbam.v4p, there is a large community of vvvv users on Skype, and most of hem are as friendly as I pretend to be. ;) We all had to learn some point. Hope to catch you on Skype some day!!