Controlling an LED strip type ws2812 using show control

[jimfitton]

How can I control an LED Strip using the WS2812 chip?

Apparently the strip has 69 RGB elements, so a total of 207 DMX channels are used.
I need to turn all the Blue channels on and off as a single action, using the Show Control interface. I can only see how to add 8 commands into a single action, and theoretically this would need 69 commands.

Can I add multiple DMX channels into a single action, for example Parameter 1 could address multiple DMX channels in one cation?

[Jorge Solano]

Hello Jim,

First of all thanks for reaching out and for the clear explanation of your setup

Yes, this is possible, and you do not need to create 69 separate commands.

On CueCore3 you can patch the strip as 69 Generic RGB fixtures and then use a single Fixture task in ShowControl with fixture range `1>69`. That way one command can set all fixtures blue at once, bypassing the 8-command limitation completely.

There is also a newer public beta firmware we are working on (1.33.0), that has a feature called Block Patch, where the whole strip can be patched as a single block fixture, making the setup even cleaner.

For CueCore2, the easiest workflow is different: create the “Blue ON” look as a recorded Track/Cue, create another for OFF, and then simply trigger those playbacks from ShowControl. Much easier and more reliable than controlling all channels individually through actions.

Also important: since WS2812 is SPI-based, you will need a SpiNode (or similar SPI decoder) between the CueCore and the LED strip.

Hope this helps!

[jimfitton]

Thank you Jorge.

I should have clarified, I'm using an IoCore2 controller, where we intend to trigger show control actions from a conventional IP based AV control system.

I've configured multiple actions with trigger values which I now need to work out how to control too!

I think my control config would be to address the unit via its IP address, then just send the string pelmetblue which is what I've determined in the trigger value test string box, with the trigger type set to message?.

[Jorge Solano]

You're welcome Jim!

Thanks for the clarification, that changes the approach a bit.

Yes, on the IoCore2 you can do this with a single UDP or TCP message trigger. Instead of only sending `pelmetblue`, I would suggest sending it as:

`pelmetblue=#0000FF`

Then in Show Control set the trigger type to Message String and the trigger value to just `pelmetblue`.

In the task you can then use DMX > Block RGB > Control. Set the start address/footprint to `1.3` and the amount to `69`. This will apply the RGB value from the message to all 69 pixels, so you only need one task for the full strip.

The nice thing is that you can later send another colour the same way, for example `pelmetblue=#FF0000`, without changing the IoCore2 programming.

And yes, you will still need the SpiNode or another SPI decoder after the IoCore2 DMX output to drive the WS2812 strip.

Enjoy

[jimfitton]

Hi Jorge,

Would there be any difference in controlling / calling an action dependant upon the DMX command being a channel, or a Block RGBW output?

I ask because I can command any of the actions using a simple message if the DMX task is to set a channel value, but if the DMX task involves Block RBGW, the TCP command is ignored.

Many thanks,

[Jorge Solano]

Hello Jim,

Yes, there is an important difference 

A normal DMX Channel > Set task works with just the trigger string because the DMX value is already stored in the task.

A Block RGB/RGBW > Control task expects a colour value to be passed along with the message. So instead of sending:

pelmetblue

try sending:

pelmetblue=#0000FF

and keep the trigger value in Show Control as simply:

pelmetblue

Also, since you're using WS2812 pixels, I would use **RGB** rather than RGBW, as WS2812 is normally a 3-channel RGB pixel.

One thing worth checking is whether the action is actually triggering. The IoCore2 Monitor page should show the incoming TCP message. If you can see the message arriving and a simple Channel task works, then my first guess is that the Block task is not receiving the colour parameter it expects.

Hope this helps!

[jimfitton]

Hi Jorge,

Thanks for the advise, and apologies for the delay in responding. Our IoCore unfortunately had to go away for repair, but its now back and I'm still working on this project.

Your guidance moved me further along, but its not quite right still!

I have the command setup in the IoCore TCP Actions.

Logo Blue, triggers a DMX Block RGBW command, for Address 103, footprint 3 fixture count 69.
When I execute this from the ioCore webpage it lights up our LED Logo in blue perfectly every time.
The trigger message is logoblue

My control system sends the ascii string logoblue=#0000FF and reliably turns on the logo, but in Green!

Any idea why this might be?

MAny thanks,

[Jorge Solano]

Hello Jim,

Good to hear you've made some progress 

The fact that "logoblue=#0000FF" reliably triggers the action tells us the TCP side is working correctly. This now looks like a colour order mismatch rather than a communication issue.

Since you're using WS2812 pixels, I'd recommend checking two things:

* If possible, use "Block RGB" rather than *"Block RGBW", as WS2812 is a 3-channel RGB pixel.
* Try sending these three commands and note the colour you actually see:

  logoblue=#FF0000
  logoblue=#00FF00
  logoblue=#0000FF

Could you also have a look at the IoCore2 DMX Monitor while sending "logoblue=#0000FF" and check channels "103, 104 and 105"?

For a normal RGB mapping, I'd expect:

* Ch. 103 = 0
* Ch. 104 = 0
* Ch. 105 = 255

If that's what the DMX Monitor shows, then the IoCore2 is generating the correct DMX and the colour swap is most likely happening in the SPI decoder or the LED strip itself (many WS2812 strips actually use **GRB** colour order instead of RGB).

Let me know the results of those tests and we'll narrow it down from there.

Hope this helps!