NeoPixel Table

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Juicebox4242
 
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NeoPixel Table

Post by Juicebox4242 »

I just have some general questions about my project as it is the largest I've done and the first permanent install.

I'm building a Beer Bottle Cap table with a Neopixel under each cap. Total number of LEDs is 162 and I'm planning on using the 5v 10A adapter here on Adafruit. I know my max Amp usage is slightly above this, but I will make sure I don't ever light them all up full power white.

1 - From what I've read about the Neopixels it sounds like I can hook them all up to one power feed in parallel with no Resistors for the LEDs. I'm just looking for confirmation on this one.

2 - cable size. I'm planning on using 18 or 22 gauge wire for the power lines. Is that a sufficient gauge?

3 - Secure wiring and LEDs to wood board - The LEDs will all be underneath a separate Epoxy Resin layer (with caps in it) suspended above them. I'm wondering if anyone has any good suggestions to keep them in place on the board. I was thinking about using some kind of non conductive glue once or something, but was thinking there might be a better way?

4 - Last one, heat - As I mentioned the LED board will be under neath an Epoxy Resin layer. It isn't sealed, but there isn't really any airflow. Do I need to add a fan to vent the inside? I was planning on having only an inch or two of space between the layers.

Thank for any guidance you can provide!

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adafruit_support_rick
 
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Re: NeoPixel Table

Post by adafruit_support_rick »

1) Yes, power them in parallel
2) 22 is fine
3) Are you using Neopixel strips of individual neopixel breakouts? Silicone adhesive should work well in either case
4) How large is the table? Are the sides of the table open? Is there any sort of wooden gridwork separating the pixels?

Juicebox4242
 
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Re: NeoPixel Table

Post by Juicebox4242 »

Thanks for the reply!

Thanks for the info. I am using individual WS2812B neopixels. My distances don't work out for the strips or I would have. I'll try the adhesive, sounds good.

The table is a Hexagon, and the space containing the LEDs is 11" on each side. No wood work between the LEDs, The sides of the table are not open. There will be hardwood on the edges.

Thanks again!

-A

Juicebox4242
 
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Re: NeoPixel Table

Post by Juicebox4242 »

One more question.

I've been testing with power from the Arduino until now. I hooked up a DC barrel jack to the circuit and plugged in a 5V 2A adapter. When I turned the Arduino on the pattern it sends to the neo pixels is really wonky. I'm just using the strand test in the example folder right now. Same circuit with the leads going to the Arduino pins and everything looks fine. Switch to the adapter and the patterns and colors seem to be random. Some of the pixels also stay lit if I turn off the Arduino first.

Any idea what could be causing this?

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Franklin97355
 
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Re: NeoPixel Table

Post by Franklin97355 »

Are you connecting the ground from your power supply to the Arduino ground (you should be)

Juicebox4242
 
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Re: NeoPixel Table

Post by Juicebox4242 »

No I wasn't. Is there a maximum amount of power that can be sent through the GND on the Arduino?

To be clear, nothing would be going through the Power supply Ground? I was powering the Arduino with the USB cable still.

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adafruit_support_rick
 
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Re: NeoPixel Table

Post by adafruit_support_rick »

You need a common ground reference between the NeoPixel power supply and the Arduino so that the data signals can make sense to the NeoPixels. There's no power going through it - it's safe.

Juicebox4242
 
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Re: NeoPixel Table

Post by Juicebox4242 »

Ok, makes sense. One more thing, just to be sure.

The ground for the circuit shouldn't terminate at the arduino, but I should connect the Arduino Ground pin to the Power supply Ground line?

So the ground path will still be through the power supply, but the arudino is just on the ground with all the other devices.

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adafruit_support_rick
 
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Re: NeoPixel Table

Post by adafruit_support_rick »

Correct

Juicebox4242
 
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Re: NeoPixel Table

Post by Juicebox4242 »

You guys rock, thanks! I'll try it tonight and let you know.

Juicebox4242
 
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Re: NeoPixel Table

Post by Juicebox4242 »

That was it. pretty lights. :)

Juicebox4242
 
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Re: NeoPixel Table

Post by Juicebox4242 »

Ok, well that worked with 10. I added another segment of 5 Neopixels to the circuit and I am having some odd glitches. In the parts of the strand test that are smooth fades, a the lights will flicker to the wrong color for a instant. In the rapid change parts a neopixel will occasionally get skipped. It does seem to get worse as it gets away from Pixel #1. The spacing is 1.5" on center to Neopixels, so jumpers are just shy of that.

Anything else I can check for?

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adafruit_support_rick
 
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Re: NeoPixel Table

Post by adafruit_support_rick »

This is on the 2A supply? Check that your connections are soldered well. Solders should be shiny and smooth,and should flow over the pad and up the wire. To get this, you must heat both the wire and pad evenly:
Image

Juicebox4242
 
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Re: NeoPixel Table

Post by Juicebox4242 »

Thanks! It is a 2A supply, eventually I'll need the 10A though.

I'm not a solder pro (yet), but they are all soldered securely. There are a couple solder points that could be better, but my biggest problem is having a slighly larger than needed solder blob. I discarded my first pack of pixels because I abused them learning to solder better.

But I don't think it is my wiring, at least not yet. I tested it with power from the Arduino and they all light up fine, so the data paths should have integrity.. I realized however, that when I switched to the power supply I forgot to add in the capacitor. I won't be able to test until Sunday, but maybe that is it?

Have great 4th and I'll let you know how it goes when I add the capacitor.

Juicebox4242
 
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Re: NeoPixel Table

Post by Juicebox4242 »

Ok, so I have some more info, but haven't fixed it.

I've tested with both 15 and 10 neopixels on Arduino power and external power supply. Both work fine on Arduino power supply, but neither work on external power supply. This is the same symptoms I had when I didn't have the arduino on common ground.

Funny thing is, it was working with 10 neopixels fine before I added the next 5. But even after completely removing data, power, and ground, from new segment the original 10 do not work properly on power supply. So I apparently have an issue with the way I'm wiring the external power supply or something related.

I was thinking maybe I damaged the ground on my Arduino, but then wouldn't it not work on Arduino power or External supply? Anything else that can cause issues on the common ground?

I have all the grounds and power leads going to respective wire screw caps with a jumper wire to next segment. On one of the ends of the ground line I have alligator clips for Arduino ground, then power supply ground.

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