Ralph A Posted May 31, 2014 Share Posted May 31, 2014 I need a little help understanding the use of A "Null" pixel. Here is my layout and potential problem. Running A San Device to 4 Mega Poles. The SD will be in the center of the 4 poles. Running, 12VDC WS2811 strips up the pole. To the right of the SD is the first Mega Pole. Distance from SD controller to the start of the WS2811 strip is 5 feet. This Mega Pole is 14 feet high and has a total of 43 pixels. Now to the far right of the SD controller is the second Mega Pole. Distance from SD controller is now 15 feet to the start of the strip. The Mega Pole is 10 feet tall and contains 31 pixels. I will not go into the other two Mega Poles because there are a mirror image of the above, but to the left. I may be able to run the above without power injection since it's 12vdc. If I need to no problem, I will do so at the base of the pole. Will set this up and test to see it power injection is needed. Here's were I fall short in my theory. On top of each of the Mega Poles I'm placing a star that is outlined in 12vdc WS2811 Rectangular Pixel Modules. If I wanted to run the pixels on the star as a continuation of the strips on the Mega Pole, of course making the appropriate DMX address changes can I use a "Null" pixel at the end of the Mega Pole strip or at the start of the star to increase my signal drop of the data? Power will be injected at the base of the star no problem there, just concerned that 20 feet on the first pole is long (distance from SD controller to beginning of pixels on star) Then it's 25 feet from the SD controller to the beginning of the second star on top of Mega pole two. Where can I read about the uses of Null pixels and how to set up the above, if I understand them correctly? Thanks for the help and advice!! Link to comment Share on other sites More sharing options...
plasmadrive Posted May 31, 2014 Share Posted May 31, 2014 From your description it seems as though your star will be right at the end of your vertical strip. If that is the case, you should have no issue with data directly out of the vertical strip to the star. Just map those pixels as the star and not the pole. I bet that since you are using 12v pixels, you may not even need to power inject.. but it couldn't hurt.. Link to comment Share on other sites More sharing options...
Ralph A Posted May 31, 2014 Author Share Posted May 31, 2014 From your description it seems as though your star will be right at the end of your vertical strip. If that is the case, you should have no issue with data directly out of the vertical strip to the star. Just map those pixels as the star and not the pole. I bet that since you are using 12v pixels, you may not even need to power inject.. but it couldn't hurt..Awesome! And yes the star is at the end of the vertical strip. Was not sure how far you can run the data before you need a "Null" pixel. Thanks for the advise plasmadrive. By the was what is the average run before you have a problem with data loss on 12vdc? Link to comment Share on other sites More sharing options...
plasmadrive Posted May 31, 2014 Share Posted May 31, 2014 2811s recondition and repeat the data at every chip. So a few feet should be no big deal. Link to comment Share on other sites More sharing options...
sax Posted May 31, 2014 Share Posted May 31, 2014 I tested a string of 30 8mm bullet pixels and 2811 led strips (50 pixels) purchased from Ray using a 12vdc 400 watt power supply. I used sans device E682 as my pixel controller. My distances were tested using prebuilt awg18 4 pin extensions sold by Ray in 5, 10 and 25 foot increments. I tested using the test sequences in the sans firmware and a sequence I made.For me I can go 25 feet without any issue on 12 v. 30 and 35 feet causes weird things to start happening. Some pixels light, some stay solid one color. Nothing that is repeatable though. At 40 feet 1 pixel comes on, the first one in the string, and that is all. Beyond that distance the pixels were all darkness in my tests.Using null pixels, I am able to get 100 ft extensions with 3 null pixels in use in between the 25 ft extensions. I only needed 75 ft so I stopped testing there knowing 100 ft is good.The only way to be sure is to test. But those were my results.Good-luck,Sax 1 Link to comment Share on other sites More sharing options...
Ralph A Posted May 31, 2014 Author Share Posted May 31, 2014 Thank You Sax!!! That is great information! I will be setting up my testing as soon as all my strips come in very soon. Trying to get a good layout in my head first. Thanks again! Link to comment Share on other sites More sharing options...
kzaas Posted May 31, 2014 Share Posted May 31, 2014 I tested a string of 30 8mm bullet pixels and 2811 led strips (50 pixels) purchased from Ray using a 12vdc 400 watt power supply. I used sans device E682 as my pixel controller. My distances were tested using prebuilt awg18 4 pin extensions sold by Ray in 5, 10 and 25 foot increments. I tested using the test sequences in the sans firmware and a sequence I made.For me I can go 25 feet without any issue on 12 v. 30 and 35 feet causes weird things to start happening. Some pixels light, some stay solid one color. Nothing that is repeatable though. At 40 feet 1 pixel comes on, the first one in the string, and that is all. Beyond that distance the pixels were all darkness in my tests.Using null pixels, I am able to get 100 ft extensions with 3 null pixels in use in between the 25 ft extensions. I only needed 75 ft so I stopped testing there knowing 100 ft is good.The only way to be sure is to test. But those were my results.Good-luck,SaxHas anyone repeated this test using 5VDC 2811 Pixels? Last year I had an extension that was probably around 30 feet with two null pixels spread throughout, I did experience some problems with what I call fluttering of the lights in that universe only when the lights were being told to be dark. When they were being used in a sequence they would work normally. Link to comment Share on other sites More sharing options...
plasmadrive Posted June 2, 2014 Share Posted June 2, 2014 Has anyone repeated this test using 5VDC 2811 Pixels? Last year I had an extension that was probably around 30 feet with two null pixels spread throughout, I did experience some problems with what I call fluttering of the lights in that universe only when the lights were being told to be dark. When they were being used in a sequence they would work normally.The Plasma Icicles were 5v WS2811 strips. I had all kinds of trouble with using pixels as repeaters. However, my pixel extender cables were in bundles and not shielded so that may have bee a contributing factor. I even made the with as little as 8' between pixels. I finally threw out the pixel cables and bought real Pixel Extenders from J1S. Then I ran almost 100' of wire with no issue at all regarding noise. I was able to go about 10' without the bundled cables.. so that is what makes me believe the radiated noise was the issue. Link to comment Share on other sites More sharing options...
Crazydave Posted June 29, 2014 Share Posted June 29, 2014 You can change the resistor is the San devices to get some distance out of them. For example I had a matrix that has 7 m lead wires 18awg. I was having issues then I change the 8 pin resistor from 270 ohm to 56 ohm and all is good. Link to comment Share on other sites More sharing options...
Ralph A Posted June 29, 2014 Author Share Posted June 29, 2014 You can change the resistor is the San devices to get some distance out of them. For example I had a matrix that has 7 m lead wires 18awg. I was having issues then I change the 8 pin resistor from 270 ohm to 56 ohm and all is good.Well that is good to know. Will that affect the warranty? Link to comment Share on other sites More sharing options...
Aaron Maue Posted June 30, 2014 Share Posted June 30, 2014 Has anyone repeated this test using 5VDC 2811 Pixels? Last year I had an extension that was probably around 30 feet with two null pixels spread throughout, I did experience some problems with what I call fluttering of the lights in that universe only when the lights were being told to be dark. When they were being used in a sequence they would work normally.I saw the same on 35-ish feet strings as well. I added one null pixel to each and this behavior improved, although I did still see the "fluttering" on occasion. More prominent the colder it got. Link to comment Share on other sites More sharing options...
Jeff Messer Posted June 30, 2014 Share Posted June 30, 2014 I think it was Dougd that told me to try and add a null right at the board. The board data is not always perfect and will cause issues. By placing the pixel at the board its perfect data from the board then. I will be testing this I hope this weekend when I layout the roof with 12v 2811 pixelbulbs from Todd. Several runs from board will be little over 30 feet on this project. I will record it and post on vimeo. Jeff Link to comment Share on other sites More sharing options...
Crazydave Posted July 1, 2014 Share Posted July 1, 2014 (edited) Jim from san devices posted it on another forum http://doityourselfchristmas.com/forums/showthread.php?28579-E682-driving-long-cable-runs-to-pixels Edited July 1, 2014 by Crazydave Link to comment Share on other sites More sharing options...
Ralph A Posted July 1, 2014 Author Share Posted July 1, 2014 I think it was Dougd that told me to try and add a null right at the board. The board data is not always perfect and will cause issues. By placing the pixel at the board its perfect data from the board then. I will be testing this I hope this weekend when I layout the roof with 12v 2811 pixelbulbs from Todd. Several runs from board will be little over 30 feet on this project. I will record it and post on vimeo. JeffJeff Lets us know what you find out. That is a very inventive idea!!! Link to comment Share on other sites More sharing options...
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