Am I damaging my NeoPixel LED strips? (Only first pixel in string is working)

[bobthenob]

#1 I am a noob with these LED strips (NeoPixel Digital RGB LED Weatherproof Strip) & am fully open to the possibility that, as I experiment with them, I may be causing damage.

Here's what's happening: I keep finding myself in a state where only the *first* pixel in the strip is working; all others are completely dark, even if the whole strip was working yesterday (all pixels are receiving power; the whole strip flashes once when I plug in). It seems that the signal isn't making it past the first pixel. If I cut off that first pixel & resolder the signal wire to the second pixel, the whole strip works again. The strip is just lying on my workbench, not undergoing any flexing or stress. Wiggling/squeezing the strip has no effect. I'm using an Arduino Mega & playing with the Strandtest sketch.

Any ideas? This has happened 3 times ... Could it be a power surge when I plug in? Other?

[adafruit_support_bill]

What are you using to power it? All pixels are wired in parallel as far as power is concerned. There will be some voltage drop from one end to the other, but the difference in voltage between the first few pixels should be negligible.

[EternalCore]

Make sure you are soldering to the DI(Data-in) side of the strip and NOT the DO(Data-Out) side of the strip. More info here: [SOLVED]Neo Pixel With Arduino UNO(ATMEGA328P-PU) NOT Working...

[bobthenob]

I'm certain the data signal isn't getting past the 1st pixel. My power source is a 12v battery via a 5v voltage regulator (and also tested with a 12/5 buck converter) sharing ground w/the Arduino. My test strip is only 20 pixels so power isn't the problem. Right now I've got the StrandTest animation running; pixel #1 is humming along happily, all other pixels are completely dark. Remember, the whole strip was working fine the other day with the same setup.

And ... I just resoldered the signal wire to the *second* pixel & the whole strip is working again.

Very confused ...

[EternalCore]

I'm certain the data signal isn't getting past the 1st pixel. My power source is a 12v battery via a 5v voltage regulator (and also tested with a 12/5 buck converter) sharing ground w/the Arduino. My test strip is only 20 pixels so power isn't the problem. Right now I've got the StrandTest animation running; pixel #1 is humming along happily, all other pixels are completely dark. Remember, the whole strip was working fine the other day with the same setup.

And ... I just resoldered the signal wire to the *second* pixel & the whole strip is working again.

Very confused ...

It might be a loose connection on that 1 pixel then. Try pressing down on it while you're testing it from that pixel and past it.

[bobthenob]

Manipulating the strip near or past the first pixel has no effect. And remember, this has happened 3 times in the past week even though the strip is just laying there.

I still suspect some kind of power surge may be frying something; I'm just plugging my power bus into the battery whenever I want to test it. Is this bad practice? Maybe there's some standard trick in protecting the LEDs I don't know about?

[EternalCore]

Manipulating the strip near or past the first pixel has no effect. And remember, this has happened 3 times in the past week even though the strip is just laying there.

I still suspect some kind of power surge may be frying something; I'm just plugging my power bus into the battery whenever I want to test it. Is this bad practice? Maybe there's some standard trick in protecting the LEDs I don't know about?

How many amps is your battery and regulator? Also What's The model numbers of the regulator? What kind of battery is it? Can you take pictures of how you wired it all up?

[bobthenob]

"How many amps is your battery" 10 Ah "and regulator? Also What's The model numbers of the regulator?" Your basic Radio Shack +5V Fixed-Voltage Regulator 7805, 1A (with only about 20 pixels, my test strip peaks at around 1A). "What kind of battery is it?" Your basic lead-acid UPS battery. "Can you take pictures of how you wired it all up?" Cheesy schematic below.

I'm wondering if placing a chubby electrolytic capacitor across the LED power connectors would dampen any power surge?

[EternalCore]

"How many amps is your battery" 10 Ah "and regulator? Also What's The model numbers of the regulator?" Your basic Radio Shack +5V Fixed-Voltage Regulator 7805, 1A (with only about 20 pixels, my test strip peaks at around 1A). "What kind of battery is it?" Your basic lead-acid UPS battery. "Can you take pictures of how you wired it all up?" Cheesy schematic below.

I'm wondering if placing a chubby electrolytic capacitor across the LED power connectors would dampen any power surge?

While a schematic is nice, real pictures would also be greatly needed to help solve your issue...
How is your regulator setup? IE: A schematic and pics would help for this too.
Are you using any diodes to protect the regulator from back-flow also are you using any diodes to protect anything?

Pictures Please.


It could help but I doubt it'll make much of a difference since your using a regulator...

[adafruit_support_bill]

Is that the complete schematic? A 7805 generally needs some external capacitors for stabilization.
http://www.fairchildsemi.com/ds/LM/LM7805.pdf

[bobthenob]

I'll try to post a pic later if that helps, but really what I've got set up is as simple as my schematic. I am not using any diodes or capacitors.
I've got some 12v-to-5v step-down buck converters (http://www.ebay.com/itm/5pcs-DC-DC-Buck ... 900377893?) that I was testing with previously, as well as one of these: http://compare.ebay.com/like/1811522239 ... s&var=sbar Would those have all the built-in protections? I'll switch to one of these & see if that improves things.

- Bob

[adafruit_support_bill]

I don't have any experience with those particular products, but I would imagine they should handle start-up transients better than a bare 7805.

[bobthenob]

Okay, I'll ditch the 7805 & let you know how I fare with the converters. - Bob

[EternalCore]

I'll try to post a pic later if that helps, but really what I've got set up is as simple as my schematic. I am not using any diodes or capacitors.
I've got some 12v-to-5v step-down buck converters (http://www.ebay.com/itm/5pcs-DC-DC-Buck ... 900377893?) that I was testing with previously, as well as one of these: http://compare.ebay.com/like/1811522239 ... s&var=sbar Would those have all the built-in protections? I'll switch to one of these & see if that improves things.

- Bob

The voltage regulators have many uses depending on how they're setup and In order to use the LM7805 properly in voltage regulator mode you NEED Capacitors.....
Here's a schematic on how it should be wired up:


Using a Bare Regulator is a NO-NO because it doesn't know what to do properly thus it becomes unstable and can even fry the things its hooked up to or even itself....

Also You should be using diodes to help protect from backflow and power spikes

So fix your regulator and diode issue then try again and report back.

I don't recommend using the 12-5v Converter Step Down Module or 25W DC-DC 12V/24V to 5V Step-Down Converter Buck Module because they are not meant for this type of application and they can fry your led pixels due to them being made for higher power applications.

For testing I recommend for you to get these: 5V 2A (2000mA) switching power supply & 12V 5A switching power supply

[EternalCore]

Here's a Schematic I made and FULLY tested for how to use a regulator properly which I'm willing to share and I'll be using it for my own NeoPixels too.

Read here: [101-Help]~12v -> 5v 1.5A Regulated Power For NeoPixels.

Also to fix your strand issue, after you dealt with the regulator issue, put a 2nd ground wire to your Arduino GND pin from the strand to stabilize the Neopixels.

-Enjoy