Flickering Pixels

[Little_b]

So I'm trying to put together a 61x63 pixel matrix.  I'm using an e6804 controller with 12v pixel nodes.   I have split the matrix into 2 halves with 4 panels per half and 465 or 480 pixels per panel.  I am using a 350w power supply for 2 panels with power injections every 100 nodes.  Each panel is on it's own output on the controller.  The issue I am having is that when I use more than one output the panels start flickering.  I've tried many things to get it to work, but with little success.  here are a few things I've tried:

 

- one power supply per panel thinking it was a power issue.

- shortening cable lengths

- adding null pixels

- hooking the pixels into longer strings to limit the number of outputs.

 

I'm sure there have been a few more I can't remember.  Anyone else have these issues before?

 

Thanks,

[Darryl Lambert]

Did you post this in another thread a couple weeks ago?

I'm guessing it hasn't been fixed.

When using 2 or more power supplies your grounds ( - ) need to be connected together. I don't know if they are or not. This means the ground to the 6804 & the pixels & the supplies should be tied together.

Did you happen to miswire any of the pixels at any time?

I have a 6804 & last season I had a string miswired due to a pigtails color order being different than the rest of them. Long story but the result was that the first pixel in the string was damaged causing the rest to act up. After replacing the bad pixel I also discovered that the 2 outputs on the 6804 were a little erratic. Sometimes they worked most of the time they caused the string to flicker.Luckily for me that I had another 6804 that was only using 2 outputs so I swapped them.

Do you have another known working controller to swap with for testing?

[Little_b]

Thanks Darryl.  I did post in another forum but felt like I was taking over in a different way so I started a new one. 

 

All the ground wires are tied together.  I've checked all the connections I put together and still no changes.  I even ran new wires to the controller.  Is it possible to short out a pixel say from signal to neg or pos, and yet still have them work?  Could that be causing the issue?  I have 2 controllers, but they both are doing the same thing.

[Darryl Lambert]

 Is it possible to short out a pixel say from signal to neg or pos, and yet still have them work?  Could that be causing the issue? 

 

Thats what happened to me. I had the ground & data reversed. Lucky for me it was just the first pixel.

Do you have any good pixels to try? Even just a couple to see.

 

Are you saying that you might have miswired them at some point? Even for a few seconds?

Direction makes a difference as well. The pixels should have either an arrow or Data in/out indicator on them.

[saxon]

You said "use more than one output " so each output works fine by itself?

Second question: do the pixels freeze after a few seconds of flickering?

I had my 2811 do this with my e6804 and it was the jumper.

[Little_b]

I've check the connections and didn't miswire them at any point.  It was easy to see since they have 3 colors.  I used heat shrink on each wire, then a bigger heat shrink on all 3 to keep them from separating.  I don't know if maybe one small wire is poking through somewhere, but I would think this would be a more serious issue.  They all work and change when commanded, but just flicker.  When all pixels are on, say all red, everything in that output flickers the same.  When it's running through a sequence it gets to be more random pixels flickering on and off  with no particular color pattern.  It's not the jumper, I removed these first thing.  Each output works fine by itself with no flickering; it's when I use more than 1 that things go haywire.

[Darryl Lambert]

Are you using multicast or unicast?

[Little_b]

Unicast.  But I've tried both ways with same results.

[Darryl Lambert]

You have 2 - 6804's, one for each half,correct ?

 Do they both behave the same way?

[Little_b]

yes and yes

[thebaronn]

Hello.

What type of pixels are you using? And do you have the latest firmware? (I only ask because I have had this issue before, and it was the firmware)

I once had an in depth conversation with Jim when the e6804 first came out. While he said that in theory, it was doable to have over 400 pixels per output, he said the refresh rate would be very low and he wasn't sure it would work. (but since you state that you have no issues 1 output at a time, I don't know if this relates)

Personally, I would fire up all outputs while the webpages are running and slowly decrease your pixels string lengths in the webserver page for the e6804. Or start at 100ct string lengths and see what happens. If it works perfectly with 100ct, then go to 150, etc. See where/if the problem begins. If anything you may be able to narrow it down to a certain pixel in a string.

and last, have you emailed Jim? He may have some super insight for you.

Good luck.

Eric

[Little_b]

Is it possible to have a bad pixel and yet still have it work?  I ask because all the pixels turn on to the color they are supposed to when doing small tests.  And how do you know if it is bad?

[k6ccc]

Depends on the failure mode. Flickering is not a normal failed Pixel mode.

[saxon]

Maybe I am reading it wrong or maybe my math sucks but, I am guessing .55 watts per node?

you say you are using 1 350 w PS for 2 panels? each panel has up 480 nodes? If this is correct then I believe you are seriously under power. 480X2=960 960 nodes at .55 watts = 528 watts. flickering is a sign of under power.

[Little_b]

As long as I don't go all white, which I don't, I'm fine.  I did some extensive measuring before I began.  (I do have more power supplies on order for this)  But even during the testing I have one power supply per panel hooked up.  Just when I think I've got it figured out, I come back a day or two later and still have the same issues.  But tonight I think I may have solved it.  I have a wire connecting neg to neg to neg on all the power supplies right at the power supplies.  Tonight I took a neg wire from each panel and hooked them all together and connected to that wire on the power supplies.  No more flickering.  So somewhere it wasn't connected enough. We'll see tomorrow. 

[saxon]

OH....Yeah that would cause problems, if I understand correctly. Without the additional neg wire, you are only solving 1/2 the problem. I always run pos and neg to every injection point. good luck I hope it works, sounds like a nice matrix project!

[Little_b]

So here is an update and I need some help.  I am now using a Pixcon 16 controller.  There are 8 panels each with it's own power supply and using 2 outputs.  I had it set up in the back yard for a couple of weeks so I could look out the window and get a better view.  I had no problems at that point, everything doing what it should be.  Now that I have it on the roof I am running into flickering problems again.  I have troubleshooted until I am at my wits end.  I have 2 entire sections that flicker.  Different power supply's and they are 2 different outputs.  All the neg are connected at the power supplies and at the matrix.  I had 2 sections flickering before, and so I added null pixels to them and the one works great, but it caused a new section to flicker after that.  When I unplug the flickering section at the controller, it still turns on, but just mimics the other half of the panel. 

 

Example: Panel 1 is on output 1 & 2 on it's own power supply.  Section 2 is flickering and mimics section 1 when unplugged.

 

At one point when I touched the bare data cable, it stopped flickering. 

 

If there is anyone who has experience with these similar issues I'd love to hear from ya, maybe even talk on the phone if necessary.

 

Thanks

[packen]

I'm not sure about the Pixcon controller, I use the ECG-P12s and had flickering problem. I went to the string config in my setup and changed the speed from 3500 to 2400. That stopped the flickering for me. Not sure if the Pixcon has that option or not. I am using the 2811 pixels. Good luck.