Ws2812b arduino cabling max distances

Projects General Guidance
1

I come across problems regarding cabling distances in ws2812b strips. Can we breakdown these limits and how to overcome them if possible?

(Note: As a power source i usually use a mobile phone adaptor, 5v at 3.1amp.)

  1. 5v power source to microcontroller, Arduino.
    Ideal max distance: I believe ideally this can be 2 meters... Not sure.

Extension: Im not sure how to extend this distance.

  1. microcontroller / arduino to ws2812b data line cable (and GND cable from arduino to ws2812b)

Ideal max : I believe data line cable to arduino is ideally kept at 1 meter max. From arduino to ws2812b strip.

Extension: Is it possible to extend this distance?

  1. power source to ws2812b 5v and Gnd lines.

Ideal max: 1 meter

Extension : Is it possible to extend this distance?

  1. powering ws2812b strips past 5 meters.

Im aware i should seperately power any line after 5 meters, directly from power source. Are there any guidelines on this?

2

Adafruit has TONS of Neopixel information and they also have a forum where you might get better answers.

The power & data are 2 different issues.

For the power you get a voltage drop depending on the wire resistance and current. Here is a chart showing Ohms per 1000ft and Ohm's per 1000 meters. A 1/2V drop is probably OK... You can calculate the length or voltage drop using Ohm's Law. (Remember to include the ground return in the distance because it also has resistance and voltage drop.)

The power traces in the LED strips usually has more resistance than the power wires and that's where the 2-meter recommendation comes-in. For long runs you need separate-parallel higher-gauge power & ground wires with connections every couple of meters (or more).

I don't know about the data line. You should be able to make longer runs with shielded wire or tightly-twisted wires (twisted data & ground wires). For example, Ethernet cables are twisted but not shielded.

3

No - not shielded!

Shielded wire has a high capacitance.

4

Capacitance is what kills the data. Twisted pair presents more capacitance than parallel runs. Shielding adds more capacitance.

This is the LED cable I use:

ledwire

I can reliably put my first LED about 4M from the controller. Note that the wire is not twisted and not shielded. If you need to go further, you can use a sacrificial LED every 4 or 5 Meters since the WS28XX LEDs clean up the data before sending it to the next WS28XX. If you don't want to mess with your LED count (you have to include the sacrificial LEDs in your LED array), then you can use a pair of inverting gates every few meters. (I don't because I use 12V WS2811 LED strings).

5

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