How to separate addressable LEDs to change the distance between each light?

Other Hardware LEDs and Multiplexing
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Hey everybody, this is my first forum post! I first touched an Arduino microcontroller for the first time 4 weeks ago. I have had no prior experience with anything electrical - only 4 programming classes in C++ and Java.

My equipment:

  • Arduino Uno R3 (from the budget pack on Adafruit)
  • LPD8806 Addressable RGB LED Strip with 32 lights per meter (also from Adafruit)
  • The appropriate power sources for the items listed above

I am currently successfully controlling all LEDs on the LPD8806 with my Arduino, so I don't need help with programming. However if anyone would like to see code, please let me know, and I'll post it.

What I want to do:
I want to lay out Addressable RGB LEDs on the ground outside over a distance of approximately 500 yards (450 meters). I could simply buy 450 of the LED strips that I posted above, but that will be very expensive (450 * $25 = over $11,000). I would prefer to have one LED every 1-5 yards (1-5 meters) and be able to adjust its position within that 1-5 yard radius of the light next to it. I know that the LDP8806 can be cut into segments of two LEDs, but I think this addressable RGB LED strip on Amazon might better suit my needs because it can be cut and separated at every light. I found a flexible addressable RGB LED strip on Adafruit that provides flexible physical positioning of LEDs relative to each other, but the wire between each light isn't long enough.

Both the LDP8806 and the other single light per segment strip from Amazon have 4 pins/connection points (5-volt, data, clock, and ground).

My proposed solution:
Buy 8 strips of the addressable RGB LED strip on Amazon to provide for roughly one light every 2 yards (~ 2 meters). Cut all the strips into segments that only have one light. Connect all the segments end-to-end with 4 copper wires running between each segment (possibly 1 single wire that has 4 stranded wires inside). Plug it up to Arduino, so that I can control each light individually.

My problem:
Since these lights will be outdoor and on the ground, they need to be able to withstand rain and even total submersion in water. If someone were to step on them while they were wet/submerged and died from electrocution, that would be bad. How might I protect against this? They also need to be able to withstand being stepped on or even kicked, so how might I protect them from that?

Will I still be able to program the lights using Arduino Uno R3 if I separate each of the segments and then reconnect over 200 of them with 4 copper wires (5-volt, data, clock, and ground)?

Is there another product that might better suit my needs? If there was something that provided for a variable distance of 1-5 yards (1-5 meters) between each LED, that would be ideal.

To avoid needing larger power sources, I won't plan to have more than 32 LEDs lit at the same time, but I would be interested in hearing about how I might power them to light them all up at once, especially if I can do it from one end of the strip.

Thanks for your help! Please let me know if I can provide more information or change my post formatting to fit what the forum expects.

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If someone were to step on them while they were wet/submerged and died from electrocution,

That is not going to happen. The electric train set used by kids has more than twice the voltage exposed on the rails and kids do not get electrocuted with those do they. The voltage is too low to pose a threat.

There are transparent potting compounds you can get that can seal the lights. Don't be tempted by normal silicon sealants as these give off fumes that over time corrode electrical components.

However your biggest problem is the distance. Signals of the sort used to control those lights will degrade when you send them over such distances. The cure is not something that you can just say to do. It requires careful looking at the situation with an oscilloscope and it is conceivable that what you want to do is impossible or impossibly expensive due to having to use a lot of buffers and drivers.

Don't spend much money until you have made a prof of concept test.

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These ws2812b leds are each mounted on a small pcb. That may be a little more robust than the strips. Also only 3 wires connect them. You would still need to protect them against weather/moisture/careless treatment. I was thinking transparent heat-shrink tube might be worth a try. Use a tube with wide enough diameter to get the little pcbs in and then see if the heat will shrink the tube enough to seal onto your cable on either side.

But, my first concern, like Mike, is that the large distances will affect the signal and prevent all the leds from working. Start small and don't waste money until you know you have something that will work.

Paul

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Thanks for the quick responses!

Grumpy_Mike:

If someone were to step on them while they were wet/submerged and died from electrocution,

There are transparent potting compounds you can get that can seal the lights. Don't be tempted by normal silicon sealants as these give off fumes that over time corrode electrical components.

This is what I found for "transparent potting compounds." I've never dealt with waterproofing electronics, so this is a first for me. Obviously, I might spend a good deal of money on this, so I have to be sure to protect it from water damage.

PaulRB:
These ws2812b leds are each mounted on a small pcb. That may be a little more robust than the strips. Also only 3 wires connect them. You would still need to protect them against weather/moisture/careless treatment. I was thinking transparent heat-shrink tube might be worth a try. Use a tube with wide enough diameter to get the little pcbs in and then see if the heat will shrink the tube enough to seal onto your cable on either side.

Those ws2812b LEDs are super cool! I'll have to order some of those.

I've never seen heat-shink tubing, but it does look pretty useful from what I saw on Wikipedia. I think it might be preferable to the potting compound. I should be able to glue or drill the lights/wiring directly onto concrete that is on the ground. Do you think that I only need the tubing over the light and the exposed cables that connect to it?

PaulRB:
But, my first concern, like Mike, is that the large distances will affect the signal and prevent all the leds from working. Start small and don't waste money until you know you have something that will work.

I already have this working on the 1 meter LDP8806 indoors, which I know doesn't prove that it's possible. I do already have 2 copper cables that were given to me by a friend that are each over 450 feet (135 meters). Do you think I should buy two of those ws2812b LEDs, find one more long copper wire, wire it all up, and see how it works?

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xcfreek58:
Do you think I should buy two of those ws2812b LEDs, find one more long copper wire, wire it all up, and see how it works?

Yes, that's the kind of testing I had in mind. I don't know if you can buy less than 10 of those leds, but they are not expensive.

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PaulRB:
Yes, that's the kind of testing I had in mind. I don't know if you can buy less than 10 of those leds, but they are not expensive.

Thanks! I'll let you know how it goes! Please feel free to post any other suggestions. I'm going to need all the help I can get!