Pixel Question

[HVACR]

I have some sets of 100 pixels. Question 1: If I add one foot of wiring between pixels 50 and 51 will it effect anything? Question 2: How does the controller know pixel one, two, and so on? In other words could I cut these in half and make two 50 pixel strips? I have a PIXIE 8 at current time. WOW lights din't have any good things to say about the PIXIE controllers.

Thanks

HVACR

[sax]

Pixels are known by the controller by how the go out....so I can have any distance between the pixels on the strand and it will just continue counting.

Example....controller-5' cable- first pixel (pixel 1) - 12" cable - second pixel (pixel 2) - 10' cable - third pixel (pixel 3).  

The only limiting factor is pixels lose their data signal after some distance.  The pixel refreshes this signal.  But if you loose the signal between pixels then you just get random flashing lights.

How far before the signal is lost?  That depends on the voltage used and the controller. The data signal is actually 5v pulses.  Typical controller chips can read the data signal as long as it is >3.5v.  So....if you are starting out with 5v pixels your distance will be much less.  The 12v pixels I can typically get 20' easily.  I have not tested this on the pixie 8.  I do have a pixie 8 but I only tested short distances.

So, you should be good for 20' for 12v pixels but honestly I would test first.  Put a 5' extension between controller and first pixel and test. Then add 5' increments until it no longer is controllable.  I typically test with a strand of 50 bullet nodes.  Once I hit failure I back off an extra 5'.

This distance can be between whatever amount of pixels you choose.  You can have a string of 10 pixels, then 10' cable (or up to whatever safe value you came up with in the above test) and then another string of 10 pixels.

But there will come a point when you no longer have the led voltage.  Usually this causes the lights at the end of the string to be dimmer than the beginning....for 12v it is the number of pixels that typically cause this.  For me I can get to about 75 without any issue.  Again, you should test this.  This is where power injection is used.

Power injection will no correct for loss data signal.  Only loss of led voltage.

Hope this helps...

Sax

[k6ccc]

20 minutes ago, HVACR said:

I have some sets of 100 pixels. Question 1: If I add one foot of wiring between pixels 50 and 51 will it effect anything? Question 2: How does the controller know pixel one, two, and so on? In other words could I cut these in half and make two 50 pixel strips? I have a PIXIE 8 at current time. WOW lights din't have any good things to say about the PIXIE controllers.

Adding a foot won't bother anything.

As for the second part, every pixel thinks it's the first pixel on the string.  The way that works, is the controller sends out a data stream for let's say 50 pixels.  The first pixel received the data stream from the controller.  Since it thinks it is pixel #1, it processes the data for pixel #1.  It then regenerates the data stream with the data for the next 49 pixels (omitting the data for pixel #1).  Pixel #2 receives the data stream with data for 49 pixels.  Again, it thinks it's the first pixel in the string, so it grabs and process the first pixel data (which is actually the second pixel data because pixel #1 stripped off the pixel #1 data).  This repeats for each pixel on the string.  By the time you get to pixel #50 (which thinks it is the first pixel in the string), it only received data for one pixel - itself.  Make sense?

 

[k6ccc]

To expand on what Sax said, different pixel technologies differ radically in how far they can go between pixels.  For example, WS2801 pixels have a very short limit, whereas GE Color Effects can go a long distance.

 

[HVACR]

Thanks for the information. That is how I hoped it worked. I didn't think 12" of  wire added but I had to ask.

HVACR