WS2812B external power issues

Hey guys

I am running a strip of 288 WS2812B leds via an Arduino nano.
I am using a 5v 10A dc-dc step down converter from 12v input.

When I run the strip from the Arduino directly it seems to light up perfectly streaming a rainbow pattern through the strip.

When I try to power it through the converter and use the Arduino to control it the strip just flashes.

Video

Any ideas?

So I've noticed if you slowly increased the number of leds to run. It seems fine up to about 160 led's. More than that and it starts doing the flashing thing.

Feed the power in from both ends of the strip.
Have you got a capacitor on the strip?

When I try to power it through the converter and use the Arduino to control it the strip just flashes.

Have you connected the ground of the DC to DC converter to the ground of the Arduino?

Grumpy_Mike:
Feed the power in from both ends of the strip.
Have you got a capacitor on the strip?
Have you connected the ground of the DC to DC converter to the ground of the Arduino?

Hey thanks for reply.

Feed at other end: I did try feed the same power source at both ends as i thought the power maybe dropping. - No change

Capacitor: I then tried putting a 1000uF 16v cap on the power source -no change.

I definitely suspect a power issue as if i turned on alternate LED's or had a small bunch moving along they did get all the way to the end.

Oh, nearly forgot, when i tested the strip with a breadboard power supply (below) it seems to work fine - but they are not rated very high on power.
.

The intention is to make this portable using 4 x 18650 Lithium cells.

Can you post a picture of your wiring then please?

So i just drew it up in Fritzing.

Sorry, my Fritzing skills are not up to much!

Fritzing is useless for showing your set up.
Your regulator may have a current limit adjustment that is set too low but you have to share the real thing.
Monitor the strip voltage though the entire failure process.

There may also be switching noise from the regulator that is causing problems.
Try a linear supply to see if there are any changes.
You could experiment with some supply decoupling, .1μf and a ferrite bead.

Show us a good schematic of your circuit.
Show us a good image of your wiring.
Give links to components.
Posting images:
https://forum.arduino.cc/index.php?topic=519037.0

I shall take the pics later this evening.

The 3 main components:
WS2812B 144/pm LED Strip - The ones i used where 2m 144 LED IP30

DC-10A-12V-24V-to-5V-50W-Step-Down-Converter

Standard Arduino Nano

Hello

1st try: Power the strip direct (!) from the output from your DCDC converter by using at least 0,5mm² wires solderd properly to the output of the converter - check if the power conection at the strip is also proper solderd - don't relie blindly on the manufactured connection, even if u buy expensive stripes the connection are often really bad done.

2nd try: If 1st try does not give success use a other more powerfull DCDC converter or even better a powerfull 5V power supply rated at least "real" (not "China") 288 * 0,04A (all 3 leds of a dot are full on)= 11.52A so 12A should be minimum.
By reading my own recommendation i am quite sure the main problem will be the DCDC converter, if it is that typical LM2576 type you can buy for about 2-4 Euro (or less).
It is a typical for a switching power supply or a DCDC converter to behave like u observed if they are overloaded.
messure the voltage direct at the powerstrip 5V and GND when running all 288 LEDs.
try to reduce the brightness (change the depending value somewhere in the sketch setup) strongly to low levels.

a multimeter and a solder iron (even better a soldering station) is a absolut "must have" in our hobby not everthing is possible and or reliable with a bread board (!)

sorry for my bad english special the grammar- hope u get it what i like to say.

Bob

Hello

ok ur DCDC converter should be very barely powerfull enough - should because 1st they say "only" 10A wich is not enough when all your LED Dots are at full brightness and even more important that the stated 10A are not really trustworthy if u use such a "no name" china source with even no datasheet.
To get a idea of a trustworthy look at DCDC converter made by Traco - but be prepared to pay a "bit" more for the "same" power.
By the way traco is really a bit overpriced for us hobbyist but it give u a idea that a your choosen DCDC converter may be not the best... :wink:
Not even 10 Euro for a 50W DCDC converter does not really work well...

Bob