Is it possible to blow neopixels out?

EL Wire/Tape/Panels, LEDs, pixels and strips, LCDs and TFTs, etc products from Adafruit

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sinefinehabitarevolo
 
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Is it possible to blow neopixels out?

Post by sinefinehabitarevolo »

Is it possible to blow the LEDs out or the IC inside? The neopixels were working fine for two days and now they won't turn on at all.

I have 940uF capacitor connected parallel to the VCC and GND, GND from the GND of power supply line to the Arduino board GND. I tried different pins on the Arduino but none of them seems to work. I checked the voltage across the 5V and GND pins on the neopixel, both the input side and output side and I'm getting 5V.

I think the data line on the neopixel (or the IC of the LEDs) isn't working because the pin 13 LED on the arduino board is flashing but nothing is showing up on the LED strip.

I've attached some pictures. I have both Sparkfun's redboard and Arduino UNO but they both do not work. Sparkfun's redboard worked yesterday and I wake up today only to find out the strip isn't working.

What should I do?

http://imgur.com/a/Nf9WR

sinefinehabitarevolo
 
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Re: Is it possible to blow neopixels out?

Post by sinefinehabitarevolo »

I fixed it but only from cutting out the first pixel out of the strip. I have no idea how the first one was damaged. I left it alone on the desk last night.

sinefinehabitarevolo
 
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Re: Is it possible to blow neopixels out?

Post by sinefinehabitarevolo »

This issue came back up again. I'm going to try cutting the first one out and see if it works again.

sinefinehabitarevolo
 
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Re: Is it possible to blow neopixels out?

Post by sinefinehabitarevolo »

Ok it works again now. The first pixel keeps getting damaged. I added an extra 470uF capacitor to see if it will help. I will post again if the first pixel gets damaged again.

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pburgess
 
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Re: Is it possible to blow neopixels out?

Post by pburgess »

Hi there,

Still trying to sort out why this is happening for a few customers and not for others. We'll replace your cooked one. In the interim, would you mind trying a few experiments?

- If you have a multimeter available, could you check the actual voltage output from the breadboard power supply?
- Also with multimeter, could you check for any voltage difference between the breadboard supply +5V and Arduino +5V?
- Are you wiring this up each time you play with it, or is it sitting as-is and the first pixel just pops without provocation next time you power it up?

If the first pixel blows again:

- Try adding a 300 Ohm (or thereabouts) resistor between the Arduino data pin and the strip input.

If you STILL blow a pixel:

- Try a different data pin (e.g. digital pin 2)

Any change? Or does the next pixel still burn out in short order?

sinefinehabitarevolo
 
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Re: Is it possible to blow neopixels out?

Post by sinefinehabitarevolo »

Hello. The voltage from the powersupply is 5.02V. So no problems there. The output portion of the LED strip also says 5.02V across 5V and GND even when the first pixel is damaged.

I will add a resistor on the data line and report back if it still damages the first pixel. Also, I will try different pin if the previous method doesn't help.

You don't have to replace my broken pixels. After all, the pixels are only a few cents and I think shipping would cost more than the 2 pixels themselves. I was worried if the entire strip was damaged. It seems that the strip doesn't all get destroyed at the same time but one by one. I am just worried if the pixels would keep getting damaged over time and if I'd have to keep cutting them.

I'm planning to order 4 more meters of neopixels anyways. I don't think 2 pixels make that much difference.

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tjwood
 
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Re: Is it possible to blow neopixels out?

Post by tjwood »

I recently received my 144 pixel strips and it looks like they have a resistor on the data line already, so maybe that's been added in recent versions.

Image

sinefinehabitarevolo
 
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Re: Is it possible to blow neopixels out?

Post by sinefinehabitarevolo »

What's the value on that resistor?

I got my neopixels three days ago but I ordered only 1 meter length. However, the neopixel guide did not specify that I may need a resistor on the dataline. As a result, 2 of my pixels were gone.

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pburgess
 
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Re: Is it possible to blow neopixels out?

Post by pburgess »

The resistor may actually be there to prevent 'reflection' on the data line; it's not clear at this point whether this is the thing popping NeoPixels for some people.

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tjwood
 
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Re: Is it possible to blow neopixels out?

Post by tjwood »

Maybe 300 Ohms? Using this calculator with the 5 band setting and orange, black, black, black, gold. Not 100% certain since black/brown are so close ... not sure what genius decided to use colors this close in the coding =P Hopefully adafruit can confirm what value resistor is needed here.

sinefinehabitarevolo
 
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Re: Is it possible to blow neopixels out?

Post by sinefinehabitarevolo »

Ok I've been working with these neopixels for three days now and I've blown 6 LEDs. All 6 LEDs were blown today. They work for a few hours then they go out one at a time. I've tried adding 330 ohm, and then 660 ohm resistors at the dataline, tried increasing capacitance on the voltage input, and tried using a different data pin. I sill keep blowing these out one by one. In a few days, I will have no pixels left...

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pburgess
 
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Re: Is it possible to blow neopixels out?

Post by pburgess »

sinefinehabitarevolo: email [email protected] with your order number and a link to this thread, and we'll have the strip replaced.

In the meantime though...let's try to get to the bottom of this. No sense hooking up a fresh strip if it's just going to pop as well. A couple items from the prior checklist that would still be helpful to know:

1. Are you connecting the strip to a 'live' circuit when this happens? Or is it when switching on power? Or just spontaneous when the circuit is running and nothing else is going on?
2. Can you measure between +5V on the Arduino and +5V on the power supply?

Bonus question:

3. How's the weather there? Is it particularly static-y?

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pburgess
 
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Re: Is it possible to blow neopixels out?

Post by pburgess »

One more question, looking at the photos: I see a breadboard power supply, then a switch. What sort of power brick is feeding into the switch?

sinefinehabitarevolo
 
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Re: Is it possible to blow neopixels out?

Post by sinefinehabitarevolo »

Thank you for your help on this.

1. Are you connecting the strip to a 'live' circuit when this happens? Or is it when switching on power? Or just spontaneous when the circuit is running and nothing else is going on?

I'm working on these to get some lighting at church. The power supply PCB isn't really secured on the breadboard so you have to be careful, but when I brought the LEDs to church to show the pastor what it looks like, one of the college kids (who SHOULD'VE known better to handle with care because he's in GEORGIA TECH!) unplugged the PCB board from the breadboard while it was live then replugged it back in. It was still working fine that time though. It was only on the next day, I was seeing problems.


2. Can you measure between +5V on the Arduino and +5V on the power supply?

They both show 5.07V.


Bonus question:

3. How's the weather there? Is it particularly static-y?

Not sure. It has been raining yesterday. However, I did not get these even slightly wet.


4. I see a breadboard power supply, then a switch. What sort of power brick is feeding into the switch?

The breadboard power supply is connected to 9V 1Amp power supply I bought from Adafruit with order number of #347175. http://www.adafruit.com/products/63 It's this one, but it looks different.

Vile86
 
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Re: Is it possible to blow neopixels out?

Post by Vile86 »

So I hate to jump on the bandwagon but, I'm also having issues with my strip of Neopixels. My four meter strip was working fine for several mins. I was only using the test code, so I was just lighting the first 60 LED's. I left it running for a few mins and went to work on another project. I notice the Neopixels start turning red... It's only at the last few of the first 60 on my strip. It's one then two.... it gets about 20 deep and nothing. The strip goes dark. I think man I guess something is wrong with my Uno or connections. Check all my connections and everything is good. So i disconnected power and then ground. I turn everything off. Turn power back on and plug ground then power in and get a slight flash along the entire strip. It's mainly red and purple. Try it all over again and get the same thing a quick flash of red and purple on several different LED's. There is no pattern or anything it's just random when you connect power. Here is a video showing this. http://youtu.be/o-qe4rvuEKg I have a short 1 meter strip so I try that and everything is fine... I tried several different digital pins and a whole new Uno, same results. I'm lost any ideas? I'm using a 1000µF/25v cap and Adafruit's 5v 10a power supply in a breadboard. I've checked the power and everything is good I'm getting 5.06v on the breadboard from the supply. Are my Neopixels just defective?

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