fastLED code bricked my Arduinos

Projects Programming
1

Hello so I used the code bellow on 3 Arduinos (2 nanos, 1 R3 uno) and now all of them are not working. They are not showing up as a COM port in the IDE and if I look at the Device Manager it does not show up there. I am using SEZO LED Matrix WS2812B Panel RGB 5050SMD 16x16 256 Pixels.`

#include "FastLED.h"

#define num_rows 16
#define num_cols 16

#define bright 255

#define data_pin 3
#define num_led num_rows * num_cols

CRGB leds[num_led];

void setup() {
  FastLED.addLeds<WS2812B, data_pin>(leds, num_led);
  FastLED.setBrightness(bright);
}

int counter =0;
void loop() {
  // put your main code here, to run repeatedly:
  for (byte row = 0; row < num_rows; row++ ){
    for (byte col = 0; col < num_cols; col++ ){
      int delta = abs(num_rows - row*2)+abs(num_cols - col*2);
      leds[row * num_cols + col]=CHSV(delta * 4 + counter, 255, 255);
    }
  }  
  FastLED.show();
  delay(5);
  counter++;
}
2

There is nothing in the code that could be a cause. More likely your wiring has caused some issue.

3

256 pixel LEDs draw way more current than an Arduino can provide - do you have an external 5V supply feeding the pixels, with only it's GND connected to the Arduino GND? It's necessary.

4

256 pixels * 3 LED/pixel * 20mA/LED = 15360mA = 15A.

5

Try 10.
Or power your LEDs correctly from separate high amp power supply.

6

With row variable of type byte and num_rows = 256 this loop will never finish

7

Sorry if this is a stupid question but i am more mechanical than electrical. So if i find an external power supply for 5V then is the 15A is the lowest i can go correct?

8

I know.

9

Point is, if the loop never finishes, how can your call to show() ever happen?

10

you know that there is no:

11

15A is power needed when all LEDs/Neopixels are all 255, 255, 255 (white, full power)

12

Disconnect all the LEDs, upload blink.ino, and thereby convince yourself they're not "bricked", nor fried. Then, continue.

13

Oh yeah i completely over looked that. Sorry b707

14

I know realize what you ment, but now i dont know what you are saying with this post.

15

at @soxrule1

This is not whatsApp where you talk to a single person.
Writing such short posts trying to be quick slows everything down for two reasons:

  1. uninformative and hard to distinguish to what such a short response relates to
  2. making less people help because they don't understand

You should:

If you don't know how to do this ask specific questions
report the result