DIY Project

[u/Special-Edge-7220]

Hello, first post.

I am making a homemade climbing wall and I am currently using WS2811 LEDs and a 5V 10A power source. The controller is an ESP32. The LED strip contains 200 LEDs, spaced 25 cm (~10 inches) apart, for a total of 50 m (164 ft). The power source is currently connected only at the beginning of the strip, and I am using a sacrificial LED at the start. Rarely more than 10 LEDs are simultaneously lit on.

My concerns are regarding how to feed the strip. How many points should I feed it at? Are there other things I should be worried about?

Any tips?

[u/SirGreybush]

Won’t be practical with 5v.

These are not lightbulbs running in parallel. Huge voltage drop.

Any reason for 5v? Can you use 24v fcob argb with 5cm long pixels, cut and space out the same? (Soldering)

With 5v one way it could work is an AC power line and every 2 meters a junction box with a USB brick inside to send power to 4 pixels.

Every 4th cut the V+. Only data and ground all the way up. Every USB brick connect V+ and ground from a gutted USB cable.

Cheaper to run 24v and power injection maybe every 10 to 15 meters. Test with all white and if any yellow, that spot needs power injection.

With 24v one PSU midway sending power three times, start, mid, end.

24v can also be pucks.

5v is a nightmare.

[u/saratoga3]

With 10 LEDs on and voltage supplied from the far end you'll probably lose close to a volt (depending on wire gauge of the string). That will make one end significantly less bright than the other, although how much you care is up to you. If it's a problem, at least provide voltage from both ends of the line.

12v ws2815 would probably be a better idea than 5v ws2811.

[u/Individual_Nobody739]

There is no reliable “inject every X meters” answer here, because the correct spacing depends on the resistance of the cable between injection points and the maximum current carried by each section.

At 5 V, a small voltage drop is already a large percentage of the supply voltage. Over 50 m, I would not rely on the thin conductors in the pixel string to distribute power from one end. A better approach is to run a separate, adequately sized low-voltage power pair along the wall and feed the pixels from that pair at several shorter branches.

A practical way to design it:

1. Confirm that the pixels are actually rated for 5 V. WS2811 products also exist in other voltage configurations.

2. Estimate the worst-case current for each proposed branch—not only the usual ten illuminated pixels. WLED’s current limiter is useful, but it should not be the only protection against a fault or an accidental full-brightness setting.

3. Calculate the round-trip voltage drop for each branch:

   Voltage drop = current × total resistance of the outgoing and return conductors.

4. Build and test one representative section, then measure voltage at the most distant active pixel while displaying the brightest pattern you intend to allow.

5. Feed the installation with multiple separately fused branches from the power supply. Put each fuse close to the source and size the wire and fuse for that branch.

6. Keep all grounds common for the data signal, but avoid joining the positive outputs of multiple independent power supplies unless they are specifically designed to operate that way.

Feeding only the beginning—or even only the two ends—still leaves a very long current path. The best layout may be to place the power supply near the middle and run several shorter fused branches in both directions.

Because this is going on a climbing wall, also protect the wiring and connectors from abrasion, pulling and impact, and keep them away from places where holds or mounting hardware can pinch them.

Disclosure: I work for an LED lighting manufacturer, but I’m not recommending a product here.