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How hot should a 24 light Neopixel ring get?
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How hot should a 24 light Neopixel ring get?

by Jim2386 on Thu Oct 12, 2017 11:30 am

Hey guys,

Been using neopixels for a long time but i've got a new problem. I've hooked up my 24 light neopixel ring to 5V and I have them all displaying 255,255,255. After a few seconds the board gets quite hot. I can still hold it, but man it's warm. The solder joints are far enough apart that there's no way I shorted anything.

I know the board is quite dense and each pixel puts out 60mA when full on.

1. Should I expect this temperature increase while running?
2. Is it safe?

Thanks
Jim

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Re: How hot should a 24 light Neopixel ring get?

by adafruit_support_rick on Thu Oct 12, 2017 11:43 am

Doesn't sound right. Probably not safe. Really shouldn't get hot at all.

Can you post some pictures of both sides of the ring?

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Re: How hot should a 24 light Neopixel ring get?

by Jim2386 on Thu Oct 12, 2017 11:53 am

IMG_2346.jpg
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Re: How hot should a 24 light Neopixel ring get?

by Jim2386 on Thu Oct 12, 2017 11:58 am

Here you go
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IMG_2347.jpg (98.89 KiB) Viewed 189 times
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Re: How hot should a 24 light Neopixel ring get?

by Jim2386 on Thu Oct 12, 2017 12:01 pm

Also having a weird issue where I'm running a 5V pro trinket with a neopixel strip. The first neopixel lights up as position 1 and not position 0 like usual. Odd.

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Re: How hot should a 24 light Neopixel ring get?

by adafruit_support_bill on Thu Oct 12, 2017 12:16 pm

the board gets quite hot. I can still hold it, but man it's warm.

They do get fairly warm if you are driving them hard. At full intensity, a 24 pixel ring will be dissipating close to 5 watts as heat.

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Re: How hot should a 24 light Neopixel ring get?

by Jim2386 on Thu Oct 12, 2017 12:27 pm

Second issue then, I've got a fat neopixel 60 strip. I've chopped it up into sections of 3 lights and put 3 wires in between each section. When I try to light position zero, nothing happens, but if I set it to light position 1, the first light in the strip lights up.

I'm pretty sure position zero is always the first light. I can't think of any way I could have wired it to make it shift position one. Here is my (WIP) code:

Code: Select all | TOGGLE FULL SIZE
#include <Adafruit_NeoPixel.h>
#ifdef __AVR__
  #include <avr/power.h>
#endif

#define PINB 5
#define PINM 6
#define PINT 8



// Parameter 1 = number of pixels in strip
// Parameter 2 = Arduino pin number (most are valid)
// Parameter 3 = pixel type flags, add together as needed:
//   NEO_KHZ800  800 KHz bitstream (most NeoPixel products w/WS2812 LEDs)
//   NEO_KHZ400  400 KHz (classic 'v1' (not v2) FLORA pixels, WS2811 drivers)
//   NEO_GRB     Pixels are wired for GRB bitstream (most NeoPixel products)
//   NEO_RGB     Pixels are wired for RGB bitstream (v1 FLORA pixels, not v2)
//   NEO_RGBW    Pixels are wired for RGBW bitstream (NeoPixel RGBW products)


Adafruit_NeoPixel stripbottom = Adafruit_NeoPixel(29, PINB, NEO_GRB + NEO_KHZ800);
Adafruit_NeoPixel stripmiddle = Adafruit_NeoPixel(29, PINM, NEO_GRB + NEO_KHZ800);
Adafruit_NeoPixel striptop = Adafruit_NeoPixel(24, PINT, NEO_GRB + NEO_KHZ800);


// IMPORTANT: To reduce NeoPixel burnout risk, add 1000 uF capacitor across
// pixel power leads, add 300 - 500 Ohm resistor on first pixel's data input
// and minimize distance between Arduino and first pixel.  Avoid connecting
// on a live circuit...if you must, connect GND first.


void setup() {
 // This is for Trinket 5V 16MHz, you can remove these three lines if you are not using a Trinket
  #if defined (__AVR_ATtiny85__)
    if (F_CPU == 16000000) clock_prescale_set(clock_div_1);
  #endif
  // End of trinket special code

pinMode(4,INPUT_PULLUP);


  stripbottom.begin();
  stripmiddle.begin();
  striptop.begin();
  stripbottom.show();
  stripmiddle.show();
  striptop.show();
  // Initialize all pixels to 'off'
 

}

void loop() {
  // put your main code here, to run repeatedly:

if(digitalRead(4)==LOW)
{
  delay(2200);
lightbottomsection(1,3);//good
  delay(3200);
  lightbottomsection(4,7);//good
delay(2900);
 lightbottomsection(8,11); //good
delay(2800);
 lightbottomsection(12,15);
delay(2000);
 lightbottomsection(16,19);
delay(2000);
 lightbottomsection(20,23);
delay(2000);

 lightbottomsection(24,27);
delay(2000);



}




}


void lightbottomsection(int min, int max)
{
for (int brightness = 0; brightness<=255; brightness++)
{
 
  for (int j=min;j<=max;j++)
  {
   
    stripbottom.setPixelColor(j, 1*brightness,1*brightness,1*brightness);
  }
  stripbottom.show();
  delay(2);
}


}



There are 7 sections of strips of 3 Neopixels each. In order to get them to light I have to break them down as shown above 1 thru 3 (including 3), 4 thru 7(including 7) etc.

From my past experience it should be 0,1,2 ....3,4,5....6,7,8 etc.

Jim2386
 
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Re: How hot should a 24 light Neopixel ring get?

by Jim2386 on Thu Oct 12, 2017 12:47 pm

Ah HA! This is an RGBW strip. That's why I'm getting weird results. What do I need to change to get RGBW library to work?

Jim2386
 
Posts: 209
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Re: How hot should a 24 light Neopixel ring get?

by adafruit_support_bill on Thu Oct 12, 2017 1:10 pm

Specify NEO_RGBW instead of NEO_GRB when you declare the strips.

Code: Select all | TOGGLE FULL SIZE
// Parameter 1 = number of pixels in strip
// Parameter 2 = Arduino pin number (most are valid)
// Parameter 3 = pixel type flags, add together as needed:
//   NEO_KHZ800  800 KHz bitstream (most NeoPixel products w/WS2812 LEDs)
//   NEO_KHZ400  400 KHz (classic 'v1' (not v2) FLORA pixels, WS2811 drivers)
//   NEO_GRB     Pixels are wired for GRB bitstream (most NeoPixel products)
//   NEO_RGB     Pixels are wired for RGB bitstream (v1 FLORA pixels, not v2)
//   NEO_RGBW    Pixels are wired for RGBW bitstream (NeoPixel RGBW products)


Adafruit_NeoPixel stripbottom = Adafruit_NeoPixel(29, PINB, NEO_GRB + NEO_KHZ800);
Adafruit_NeoPixel stripmiddle = Adafruit_NeoPixel(29, PINM, NEO_GRB + NEO_KHZ800);
Adafruit_NeoPixel striptop = Adafruit_NeoPixel(24, PINT, NEO_GRB + NEO_KHZ800);

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Re: How hot should a 24 light Neopixel ring get?

by Jim2386 on Fri Oct 13, 2017 5:13 pm

adafruit_support_bill wrote:
the board gets quite hot. I can still hold it, but man it's warm.

They do get fairly warm if you are driving them hard. At full intensity, a 24 pixel ring will be dissipating close to 5 watts as heat.



Is there any way to know for sure? I’m giving these neopixels as part of a gift. I’d hate for it to melt something or worse!

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Re: How hot should a 24 light Neopixel ring get?

by adafruit_support_bill on Fri Oct 13, 2017 8:24 pm

If it is operating normally, but warm overall, then it is most likely normal. A short circuit would cause localized overheating and the ring would not function properly.

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Re: How hot should a 24 light Neopixel ring get?

by Jim2386 on Sat Oct 14, 2017 10:16 am

So I think I found to root cause of the noisy lines. To fix it I need to solder to two power wires +5v and gnd to the back of the board under the USB port. Can anyone confirm which color circle in the picture should have the 5v line attached and which color is ground?l

0311B6F9-ED62-4A0D-9CBC-FD066D129965.jpeg
0311B6F9-ED62-4A0D-9CBC-FD066D129965.jpeg (425.37 KiB) Viewed 101 times
Attachments
61E52138-6FE4-4A16-87DD-E337D5013634.jpeg
61E52138-6FE4-4A16-87DD-E337D5013634.jpeg (425.37 KiB) Viewed 101 times

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Re: How hot should a 24 light Neopixel ring get?

by adafruit_support_bill on Sat Oct 14, 2017 11:35 am

All of those are mounting pads for the USB jack. They are all connected to GND.

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Please be positive and constructive with your questions and comments.