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Topic: Long length of addressable LED's? (200ft) (Read 958 times) previous topic - next topic

Shanedm1

So I want to install a long continuous run of about 200ft of addressable LED's. Is there a rule of thumb with how far along the LED strip there should be a power supply? I am sure that it needs to be powered along the strip to ensure the brightness (and voltage) remains fairly constant so dimming isn't an issue.

So for 200ft, any recommendation how far along I need to have it powered?

Also, is there a preferred addressable strip for 200ft? The WS2812B? Those have worked well for me, but I have no experience with very long runs.

Thanks!!!

PaulRB

#1
Aug 02, 2019, 08:17 am Last Edit: Aug 02, 2019, 08:23 am by PaulRB
Important questions here are what voltage the strip requires: 5V, 12V, 24V... and how many LEDs per metre: 30, 60, 144... These answers make a huge difference to your question.

With 12V strips, LEDs cannot be individually controlled, but each group of 3 LEDs can. With 24V strips, groups of 6 LEDs can be individually controlled. This more coarse level of control is often ok because it is less noticeable with longer strips. The big advantage is that current requirements are significantly lower, making wiring easier, powering the strip at fewer points with somewhat thinner wires.

PaulRB

Another limiting factor to bear in mind is that basic Arduino like Uno, Nano, Pro Mini can only control around 500 LEDs because of ram memory limitations. (However, for 12/24V strips this means up to 500 groups of 3/6 LEDs can be controlled). If you need more than 500 LEDs or groups of LEDs, this does not mean you must have a Mega, although that would work. There are plenty of compact Arduinos and compatibles available these days with far more ram memory. Most of them are 3.3V devices, and will need a logic level shifter (not one of those sold on eBay for i2c level conversion, use a 74hc14 chip or similar).

Shanedm1


Shanedm1

Your post and info is extremely helpful and insightful. Thank you!

What is a logic level shifter? -sorry for the noob question...
This is a project I'm taking on so any info is appreciated.

noiasca

DE: Wie man Fragen postet:
1. was hat man (Sketch und Hardware)
2. was SOLL es machen
3. was macht es: IST (Fehlverhalten, Fehlermeldungen, Serial.Output ...)
4. Eine Frage stellen bzw. erklären was man erwartet

Paul__B

You do not need a level shifter if you are controlling the strip with 5 V logic, you will if using 3.3 V logic.

I would suggest you need to parallel in power every three Amps or so.  For 60 mA LEDs, that means every 50 LED groups; the group for 24 V being 6 LEDs.  You want to use heavy duty twin cable - at least as heavy as household (fixed) wiring for the same current levels or in proportion.

Please cite these 24 V LED strips so we can check exactly how they are configured.

Note the critical requirement to run supply, ground and data wires together wherever they go.

Shanedm1

A makes total sense !
Since I'll be using about 200ft and the application will be to illuminate the ceiling of a home by placing them on a coffered ceiling so they shine on a ceiling I don't need the individual LED control, so a 24V setup is the way to go.

PaulRB

https://www.google.com/search?client=firefox-b-d&q=What+is+a+logic+level+shifter
Although the explanations found by that search are good, many of the images google shows are the bi-directional, i2c logic-level shifters I was warning about. They are known to work poorly or not at all with led strips.

Wawa

I would suggest you need to parallel in power every three Amps or so.  For 60 mA LEDs, that means every 50 LED groups; the group for 24 V being 6 LEDs.
Current on a tap goes both ways...
Leo..

Paul__B

Current on a tap goes both ways...
Absolutely - it would be inappropriate to break the power line unless it is to "section" it to a second or subsequent separate power supply, in which case is it essential that the grounds still be closely bonded together with the data line together with the ground but you should have another 470 Ohm resistor in series with the data line at that point.



You would certainly not use the "bi-directional, I2C logic-level shifters" for this purpose, rather a 74HC04 or preferably a 74HCT14 with two gates in cascade.

Wawa

 :o Not sure if you get it.
6Amp into the tap is 2*3Amp into the strip (100 LEDs/groups, not 50).
Leo..

Shanedm1

Yes I understand the concept that the long strip requires power along the length. Is this something that I can buy off the shelf? Or something I'd have to solder up myself (DIY) ?

Has anyone done a long length similar to 200ft or longer?
Any other tips or suggestions?

Thanks !!

PaulRB

#13
Aug 03, 2019, 09:14 am Last Edit: Aug 03, 2019, 09:15 am by PaulRB
You can buy connectors to join strip to strip and cable to strip off the shelf.



PaulRB

You still need to answer the question of how many LEDs per metre.

At 30 LEDs per metre, you are looking at 1,800 LEDs in groups of 6 which is 300 controllable pixels.  That's not too many for a basic Arduino like a Nano or Pro Micro to control. They are 5V devices, so no level shifter would be needed between the Arduino and the strip. You would however, need DC-DC convertor to power the Arduino, as they can't take 24V power directly.

At 60 leds per metre you have 600 controllable pixels. That's getting very close to the limit for Nano/Pro Micro.

So another question is do you need to control all LEDs (meaning groups of 6 LEDs) individually? What patterns and effects do you want to achieve? If some parts of the strip can be reflections of other parts, this can reduce the number of groups that need to be individually controlled.

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