My first "big" WLED project - am I doing this right?

[coolinger]

Hi all!

My daughter and I want to install a LED setup in her room. Is my thinking correct or am I missing something important? Use case and question at bottom, I want to share my thoughts about hardware first.

The setup will consist of three LED bars, arranged in U form, on left and right wall as well as the front wall (viewed from desk) → “center”.

The sides are ~330cm each, the front ~260cm. Total of ~920cm.
The side’s first LEDs are both at the center.

We want to use “BTF-LIGHTING RGBW RGBWW SK6812” 5V 60 LEDs/m, from which I still have a 5m roll left over.
The strip shall be placed in a 45° alu profile, along the top wall corners.

I want to power it with two 5V12A transformers, and wire it with 24AWG. I hope to be able to use the aluminum profiles for the cabling.
Operated by two or three or four ESP32+relay.
Power is divided at the relays, injected at both ends of the three led strips.
Would mid-injection work better?

Planned usage:
Simple light ( for improved wife-acceptance-factor )
Audio visualization w/ LEDfx:
Both sides display an spectrometer like effect, while the front strobes to the beat. The sides should go synchronously.
I think the best solution for this special case would be to connect the side strips to the same PIN?

Ambient lighting with effect.
Kids, right?
We want to be able to show a non-audio effect going seamless through the room, e.G. a wipe from back-left over front to back-right, as well as e.G. rainbow going synchronized on the sides, while audio-reactive-strobe on the center.

Ambient light for the display.
On my workstation, I have a hyperion running. I would do something like this, but with a lot fewer but larger grabbing zones. Mixing this with audio-reactiveness could also be cool, like the sides are hyperion, the center is LEDfx.

Setup:
I plan to play around with the following setups:

• One ESP (One pin per strip/sides on one PIN and front on another):

  • WLED-Effects should work best
  • LEDfx cannot distinguish between the three strips

• Two ESP (Front on one ESP, Sides on one ESP(same pin/two pins))

  • LEDfx can distinguish the side strips, unless on same pin
  • WLED effects still seamless?

• Two ESP plus orchestrator (Front on one ESP, Sides on one ESP(same pin/two pins), one dedicated controller/orchestrator)
  same as above, but one additional ESP has both ESPs as DDP RBG

  • I am losing the warmwhite LED

• Three ESP (left/right/center)

  • WLED effects
  • LEDfx

• Three ESP + orchestrator

  • WLED effects over orchestrator
  • LEDfx directly on lights
  • wifi “traffic jam” when all ESPs are too close together

The three plus one solution might also give the possibility of integrating Alexa voice commands as well as a physical switch.

Any recommendations from experienced users?

[divsys]

What do the specs for those strips say is the maximum power required?

A typical guess would be 0.3W/LED => 5m x 60LED/m x0.3W/LED = 90W maximum.
At 5V that strip would need 90W/5V= 18A.

Your 2 x 12A supplies could be sufficient, but the choice of 24AWG wire for power is probably poor.
Voltage drops across that wire will likely cause you significant problems.
You can estimate the drops by figuring the maximum distance from the physical supply to the strip injection point. In your case, I would guess something like 3 to 4m (floor to ceiling plus distance to the middle of a strip). Then use a voltage drop calculator like:Voltage Drop Calculator - Inch Calculator to plug in wire sizes, lengths and the current you expect the wire to supply.

In your case, if you inject each supply at the 1/3 and 2/3 point along the whole strip each supply needs to provide a max of 9A. If you try and pass 9A through a 24AWG wire (even if you split it across 4 pairs - so 2.25A each pair) you won’t get more than 1m before you see significant drops. I would suggest you move up to at least 16AWG wire (14AWG would be better) and if you can route it in a neat or “hidden” fashion add at least 2 injection points per supply for a total of 18A across 4 wires => 4.5A each. Mid injection is always better IMHO, it tends to distribute the inevitable drops more evenly.

All of this is based on my guess of 300LED’s at .3W/LED => 90W of power in the worst case.
You would be well served to actually measure the worst case scenario on the bench before things get mounted. The actually current draw at max brightness is the critical value. You can drive 10 LED’s at bright white and multiply the measured current by 30 to get what you need for your strip.

Don’t underestimate you current requirements and/or the voltage drops from wiring.
Many installations are plagued by glitches/flickering/weirdness that only happens randomly at higher brightness levels. I’d much rather spend time at the table figuring what I need ahead of time rather than chase power induced problems. Design it right the first time.

Just my $.02

[coolinger]

Thanks for your detailed and helpful reply. I did not think about the power drop inside the actual power cable, I thought it was only the LED strip.

You are correct with your power requirement guess.

My initial idea was to pipe the cable all the way through the profiles at the ceiling. The PSUs would be on the floor (hidden under the bed), the box with the ESPs and relays on top at the beginning of the first side profile. So the complete length from PSU to end of last strip would be around 12m.

I wanted to put the cables inside the profiles, in the free space under the LED montage floor (the profiles are similar to this PXG-1616 Angled aluminum profile for led light bar large size led linear light aluminum profile channel extrusion frame for led, China PXG-1616 Angled aluminum profile for led light bar large size led linear light aluminum profile channel extrusion frame for led Manufacturers, Suppliers, Factory - Zhongshan Paralight Lighting Technology Co., Ltd), and drill holes wherever I wanted to hook it to the strip.

I tested what I have here: one 5V12A transformer (meanwell lpv-100-5) attached to the esp32 and then to one RGBW 0,3W/LED 5m 60LEDs/m strip (SK6812 RGBW 4 in 1 Pixels Individual Addressable Led Strip DC5V – BTF-LIGHTING). I had to set the max. amp in WLED’s settings to 11 amp, otherwise it would reboot randomly. But I did not see any flickering when activating all LEDs (RBG-White+Warmwhite) after this.

Since this test was only with short cables, I will test with the actual cable length.

Thanks for this info!

[divsys]

If you can I would physically measure (use a meter) the current draw on strip with only 10 LED’s set to maximum brightness and full White. That will give you real world numbers to work with. The limiter settings on WLED are a nice “last ditch” for power IMHO. I prefer to work with what the strip really needs and make sure my power is clean. Flickering and other “oddities” always seem to happen when you least expect it and after you think it’s all been good, so what could go wrong?

Keep at it, looks like you’ll have fun putting this one together!

[coolinger]

But for the data cables, 24AWG is fine, right?

[divsys]

The data lines carry no real power so voltage drops are not an issue.
Total length becomes an issue as the line can act as an antenna and pickup noise.
24AWG esp. UTP is not a bad choice in general for data.

[coolinger]

Thanks all, I finally have the first 3 meters/180 LEDs on the wall! Power connected only at the beginning of the strip for a first test.

Another (perhaps stupid) question: Is it enough/dangerous/without effect if I only supply the 5V (without ground) to the other end of the strip?

[divsys]

Not dangerous per se, but it will only inject about 1/3 of what you’d like for increased power supply. Injecting only +5V and not the extra GND means the existing GND wire has to handle twice the load. I still suggest injecting at the middle(s) of the strip to more effectively even out drops across the whole length rather from one end to the other.