5 Strip LED project

Other Hardware LEDs and Multiplexing
1

I'm working on a 5v 10a LED project which involves 5 strips fed by a 5v/10a power supply. It runs through a soldered board, with 470ohm resistors in line to each strip. There is also a 1000u capacitor to smooth things out.

The oddest thing is happening that no engineer or electrician in my circle (nor google) can seem to solve. Some of the strips flicker rapidly, except when my laptop is plugged into an outlet on the same circuit. In this test it happens to be the outlet on the other side of the room. The laptop is a dell with a 19v charger. The computer has to be plugged in and on for the flicker to stop. Note, the laptop is not hooked up to the Arduino in any way.

All connections appear to check out fine.
Plug is grounded, verified that it is properly grounded.
Multiple outlets checked.
Limited on checking a different circuit.
Lights are controlled through a BT code, all respond but the flicker persists. Rapid and consistent.
Flickers regardless of dim level, 0-100% power results in same flicker

Another power supply is on order.

Any ideas? I searched everywhere before coming here.

Thank you!

2

Have you connected the ground of your 5V supply to the ground of your Arduino? The laptop may be making this reference connection for you.

3

What kind of LEDs? What do you mean by flicker? What happens when you run fewer strips? What's your program? Have you measured psu voltage under load?

4

Thank you both so much for answering quickly.

  1. I have a ground wire running to the ground pin on arduino
  2. WS2812B lights
  3. They rapidly flash colors. It seems to be going through a bunch of colors very quickly.
  4. I can't test fewer strips but I did lower the output which I would expect to do the same thing (less draw).
  5. I measured voltage and it drops to about 4v at some points beyond the board.
5

Wrong colors and erratic behavior is a sign of being underpowered.
Of course you can run fewer strips to test. Unplug them or code them out.

6

If underpowering is the issue, then why would having a laptop plugged into the same circuit correct the problem? As a reminder, the laptop has no connection to the board other than being on the same circuit.

I'd love for the power supply to be the issue as i'm getting the manufacturer to send another.

7
  1. I have a ground wire running to the ground pin on arduino

From where? It should be from the power supply and the strip all commoned up.

It does sound like a grounding problem to me.

8

They are all soldered together. I think your assessment is the most logical. I will check all of my ground connections again asap. GF is going to kick my a' if I don't stop staring at it.

thank you again for your quick advice. I will report back when possible. It looks great when working.

20746684_10110309494731763_742016668_o.jpg
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9

Does the behavior change if you turn on/off the BT on said laptop?

10

behavior is consistent. It seems that it's more rapid when more "data" is being sent to the strips. All white is noticeable but rainbow is more visible.

11

How are the strips connected? All end to end or star or what? How many LEDs? Saying '5 strips' tells us nothing about length. 5 5meter strips? 5 5inch strips?

12

30 leds per strip model listed in original post. On mobile sorry for brevity.

13

JeremyC:
30 leds per strip model listed in original post. On mobile sorry for brevity.

Still not a clear answer, but it now sounds like you only have 5 1-meter strips with 30LEDs/meter. 150 LEDs total.

The 10A power supply is more than enough.

Can you explain the mysterious 'soldered board' and resistors? Are they on the data lines? Sounds like a star formation, then? Does that mean you're using 5 separate pins for data on the Arduino? What's powering the Arduino?

14

INTP:
Still not a clear answer, but it now sounds like you only have 5 1-meter strips with 30LEDs/meter. 150 LEDs total.

Can you explain the mysterious 'soldered board' and resistors? Are they on the data lines? Sounds like a star formation, then? Does that mean you're using 5 separate pins for data on the Arduino? What's powering the Arduino?

  1. Yes
  2. 5 separate pins. Arduino is being powered by the same power supply. Resistors are on the data lines. The main power line splits into two which power 2 & 3 strips respectively. My main fault here is not recording which are grouped. The strips are encased and hard to get to but I can tear it up if need be.

New development in trying to isolate the problem. I have a fishtank light powered by a driver that takes in 95-265v and outputs D24-45v, 1200ma. When I unplug that light the flashing stops completely.

To summarize,

Fishtank light on, Laptop unplugged - Flashing rapidly.

Fishtank light on, Laptop plugged in - Flashing less rapidly than the above

fishtank light moved to an outlet further away but still on the same circuit - Flashing but less rapid than all other scenarios.

Fishtank light off - NO flashing at all (regardless of if the laptop is powered up or not).

I tried unplugging other things on the same circuit and they had no impact.

To note, the following are all powered at the same time on the circuit:

TV
Cable box
Soundbar & sub
12 60w bulbs
55gal fishtank filter, standard light (not the high output listed above)
Speakers

15

Ok this fresh information seems to imply your fish tank lights are generating interference that your Arduino or strip lights are picking up.

This could be either radiated or conducted through the mains. If the latter a mains filter would cure it. If the former then look at some form of snubber circuit on the fish tank lights.

16

What kind of bulb(s) are on the fishtank light? I hear cfl and led can cause interference so you can try switching them out for incandescent ones if possible. And also if it goes through some kind of transformer or psu then that might be introducing the "noise".