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Grid and long Cables with E682


kiplorenzo

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Hi all,

 

I am building a grid for the yard. The Yard is 100X100 ft. I've built the lights 5ft apart from each other and the string is 100ft long with 20 pixels of 3 LEDS each

.http://www.aliexpress.com/store/product/20pcs-DC12-WS2811-pixel-module-with-transparent-cover-3pcs-5050-led-inside-0-72W-30mm-diameter/701799_1730325644.html

The Strings will also be 5 ft apart.

The Challenge: The Data Line signal  from the E682 does not reach the pixels. I am using 18 Gauge (Monoprice-http://www.monoprice.com/Product?c_id=102&cp_id=10239&cs_id=1023904&p_id=4043&seq=1&format=2 )

to run power and Data 50 ft from the controller. I built the cable with the connectors and the lights all stay white. What it seems like is the dataline is not getting to the pixels to tell them what to do. I've double checked the connections, and even tried 18 gauge wire from Ray Wu.

 

Thoughts here? I am using 2 29amp power supplies from Ray Wu:

http://www.aliexpress.com/store/product/12V-350W-switch-mode-power-supply-LED-power-driver-AC90-260V-input-DC12V-350W-output-constant/701799_1948832565.html

 

Am I missing something here or is 50 ft too long of wire to go from the E682? In which case I may need to look at the 6804's

 

 

 

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The E682 says to not do that and that was going to be my next question....

Will the E682 set it up by channel group? example 1-1 has 5 nul pixels, 1-2 has 4 nul pixels 1-3 has 3 nul pixels...

etc.

 

Thanks

Edited by kiplorenzo
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How about adding those channels to your sequence and leave them blank, this way they are getting a no on command and passing on the rest?

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Thanks all, I think i figured this out...

On the Front end, a few Null Pixels... with Power injection (does one use the ground on the transformer or the Positive?) on the back end.

 

Thanks

 

Kip

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Check your e682 manual again. They do list null pixels as a work around for longer distances. In the output configuration section there is a spot to identify null pixels.

You install them inline between strings/strips. wire them like any other pixel.

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Using ws2811 pixels... I have leaders that are 20-something feet from the controller to the 1st pixel.

 

In order to make this work, I had to change the resister network from 270 ohms to 56 ohms.

Mouser Part:
http://www.mouser.com/Search/ProductDetail.aspx?R=4608X-102-560LFvirtualkey65210000virtualkey652-4608X-2LF-56
 

 

Reference post from SanDevices:
http://doityourselfchristmas.com/forums/showthread.php?28579-E682-driving-long-cable-runs-to-pixels&highlight=resistor+network

 

 

 

If you are encountering issues such as pixel flickering when trying to drive pixels over a long cable run (say more than 15-20 feet) with the E682, this can sometimes be cured by replacing the pluggable resistor network that drives that output with a different value.

There are 8 pluggable networks on the E682, each drives the 2 output connectors immediately beneath it. The default value is 270 ohms, indicated by a part number containing "271" 27 followed by 1 zero = 270.

A smaller value can often help when driving long pixel leads. There are a couple of ways to test this without having to have different resistor networks available.

You can use individual 1/4W or 1/8W resistors (say from Radio Shack), or you can use small wire jumpers (effectively 0 ohm resistors).

Remove the resistor pack above the output to be tested. This will leave 8 empty socket holes, 1 thru 8 from left to right. Form the resistor or jumper leads into a "U" shape with the legs equal lengths (about 1/2") and about 1/10" apart.

For 3 wire pixels such as 2811/2812, only one resistor or jumper is needed per output. For the upper jack of the pair, insert the resistor or jumper between contacts 5 and 6, for the lower jack use pins 7 and 8. Power up and test the output.

If you are using resistors, I would try starting at 33 ohms and working up. Go one standard value less than the highest value that works reliably. For example, if 56 ohms works, but 68 ohms appears flaky, go with 47 ohms.

If you are doing the test with jumpers, if the output works properly with the jumper in place, then I would suggest purchasing the Radio Shack resistors to identify the best value.

The resistor networks can be purchased from any electronic supplier. They are "83" series, 8-pin networks containing 4 individual resistors. A typical part number would be: 83S560. The resistance is shown by the 3 digits after the S. 2 significant digits and the 3rd digit represents the number of 0s. So 83S560 is a 56 ohmresistor, "56" followed by no zeroes. 
83S101 would be 100 ohms "10" followed by 1 0 = 100.

 

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I just went through this using a similar cable and I couldn't get further than 10ft. The pixels would flicker on white. The other colors were fine. I just added a null pixel at 5ft and cleared my problem. Seems very short but the cable is the problem. Next year will use a better cable.

 

I also had a space between 2 pixel runs that is 12 feet apart on one of the outputs. Since it wasn't at the beginning, I couldn't add the null on the controller. So I added the null pixel and just removed or bypass that that channel in the sequence.

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One thing I have done is to use Shielded CAT6 cable for the data lines. I wanted to run 4 data lines over the same connector and had no dice using the standard Ray Wu 4 pin cable. The data lines would interfere with each other and result in random blinking. This year with shielded CAT6 I have tried up to 25 ft without any issues. The shield is tied into ground in the controllers...

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Crazy Dave...great info. I haven't even looked at that part of the manual in detail. I remember reading it now that you posted it. That might explain why sans doesn't go as far as the Joshua boards...It can but requires the resistor network to be changed. I wonder why this network is even needed....

Even though in testing, with all my extensions, nulls, pixels and controller connected on the living room floor (yeah the wife loved that bundle of mess) I was able to verify the 25 ft extensions with null pixels in between worked, once up in the yard I started having flickering. My final working yard is:

I was able to get 20 feet max to my pixels using extensions from Ray and then adding a null pixel. Total distance is 50 feet for a string of 30 pixels. I do this 6 times for 2 elements.

I was able to get 10 feet max for my 2811 strips and then throwing in a null. I only needed 20 ft here for 2 separate elements so I just threw a null at halfway to clear up the flickering. 15 ft may of worked.

You can add up to 4 null pixels per output on the e682.

I have ordered some beldin cable that has 2 awg 18 and a shielded twisted pair wires that is classified as thermostat controller cable but it is on back order. I talked to my supplier and should have it next week. But it is pricey cable. I will begin testing that ASAP.

I would like to play with the resistor networks to see if I can increase my data throw using Rays extension cables. It would definetly be a cheaper alternative than that beldin 1502 cable.

Unfortunately my only sans is playing shows right now. And normally that would not matter as I could just work on it during show idle moments. But the rains have come here in Oregon and I don't won't to remove the device to test. So it will be added to my to do list in January once I break everything down. (Except my pixels. I will leave them in the yard until testing is done since apparently on the floor in the living room can't detect all the problems).

I Plan to purchase a new 6804 for testing and backup and eventual full time use but that is next years budget. I don't know if it will work the same as the 682 for distance. I will test that in January as well.

Edited by sax
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since last year I'm running from the sandevice to CCR a 25' long cat 5 for each CCR, what I did was group the cat 5 in 3 pairs (blue with white-blue, green with white-green and orange with white-orange) with no problem, right now I'm running one 50' long cat 5 for the most far CCR with no problem and no power injection.

I tried to use a cat 6 cable in the same way but it didn't work properly so for me the cat 5 cables works very well.

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Crazy Dave...great info. I haven't even looked at that part of the manual in detail. I remember reading it now that you posted it. That might explain why sans doesn't go as far as the Joshua boards...It can but requires the resistor network to be changed. I wonder why this network is even needed....

 

 

Lowering the Resistor value does this:

 

 

Somewhat less protection against damage due to an accidental short between clock or data lines and +V.
Edited by Crazydave
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By lowering the resister value to 56ohms... you should be able to run much longer distances without needing a null. 

my experience is that 56 was sufficient to go 20 feet using 18awg wire but I'm sure it can go longer, I just didn't have a need to.

So based on that info, I should be able to increase the resister by some amount...and gain back some short-circuit protection

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