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Run WS2812 strip from wrong end
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Run WS2812 strip from wrong end

by Exterior on Sun Jul 28, 2019 7:00 pm

Hello again

I made a stupid mistake and now I'm looking how solve this.

I build up a setup of two strings with WS2812 LEDs. I control both of these strings with a arduino.
But due to my lack of experience, I din't really pay attention to the arrows on my strips. I had that statement "it doesn't matter, where at the strip you feed in the voltage" in mind and somehow thought of it as "orientation doesn't matter at all, electricity finds its way"

So now, my power supplies and my arduino are placed at the end of the strips, not at the beginnig. So now, when I connect my arduino, nothing lights up at all (of course not).
Coincidentally, I managed to get the orientation wrong two times, so now, both strips are installed in a way, that the arduino is placed at the end of the strip.

Do you have any recommendations on how to solve this? Removing the strips an reinstall them in the correct orientation will be nearly impossible, so I hope, you've got some other ideas.
The length of one strip is around 10 meter (around 33 ft).
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Exterior
 
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Re: Run WS2812 strip from wrong end

by adafruit_support_bill on Sun Jul 28, 2019 7:38 pm

Can you move the Arduino to the start of the strips?

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Re: Run WS2812 strip from wrong end

by Exterior on Sun Jul 28, 2019 7:41 pm

That would be easier then reinstall all the strips, but would be pretty difficult, too :-/

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Re: Run WS2812 strip from wrong end

by adafruit_support_bill on Sun Jul 28, 2019 8:16 pm

One way or another, you need to get the signal connection to the start of the strip. Very long signal runs are not recommended. It is best to have the controller within a meter of the first pixel - preferably less.

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Re: Run WS2812 strip from wrong end

by Disciple on Mon Jul 29, 2019 1:55 am

Would substituting a smaller controller board for the Arduino, like a Feather or ItsyBitsy, make relocating the controller more feasible? Just a thought.

Hallelujah!
Disciple

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Re: Run WS2812 strip from wrong end

by adafruit_support_mike on Tue Jul 30, 2019 1:56 pm

For long wire runs, you can use a dummy NeoPixel every meter or so along the wire.

Each pixel buffers the signal to the rest of the strip, so dummy pixels can be line extenders. Just set the RGB values to 0 for that pixel in code.

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Re: Run WS2812 strip from wrong end

by Exterior on Thu Aug 01, 2019 9:05 am

Hey guys, sorry I kept you waiting.

The project will run with a Teensy 3.6 after all, which is smaller than the arduino. Maybe I can try to place the Teensy at the "end" of the strip.
Would it make a difference if the Teensy isn't located at the point where the power supplies are, but at the point farthest away from them?
What about the common ground? Can I connect the common ground with one of the power feed-in-points?

@adafruit_support_mike
Yeah, I know that dummy pixel stuff, but the distance is quite long. Would I have to connect all three lines (+5V, Ground and Data) or would Data be enough?

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Re: Run WS2812 strip from wrong end

by adafruit_support_bill on Thu Aug 01, 2019 9:27 am

Would it make a difference if the Teensy isn't located at the point where the power supplies are, but at the point farthest away from them?

It is not a problem for the Teensy to be connected at a different point that the power supply .

What about the common ground? Can I connect the common ground with one of the power feed-in-points?

You should have a direct ground connection between the Teensy and the first pixel.

What about the common ground? Can I connect the common ground with one of the power feed-in-points?

The dummy pixels would need power and ground as well as signal connections.

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Please be positive and constructive with your questions and comments.