I have both an Arduino Due and Arduino Mega 2560, for this example.

I have both an Arduino Due and Arduino Mega 2560, for this example.

For the below code. and in many instances of other sketched that use FastLED I am seeing the behavior.

When running the below code on the Mega or Uno it runs with no problems.

When using the same exact code on the Due it will run through the cycle once and then stops. in other sketches it will not even start (but will work 100% on the Mega) I did notice however sometime when I unplug it from the USB. the LEDs will suddenly change to a frame in the code that you where not able to see before. almost like it is running the code but not updating the pixels.

#include “FastLED.h”

#define NUM_LEDS 50

CRGBArray<NUM_LEDS> leds;

void setup() {
FastLED.addLeds<WS2811,53>(leds, NUM_LEDS);


void loop(){
int randNumber = 0 ;
static uint8_t hue;
for(int i = 0; i < NUM_LEDS; i++) {
// fade everything out
randNumber = random(0, 255);
// let’s set an led value
//leds[i] = CHSV(randNumber,255,255);
leds[i] = CRGB(255,0,0);
leds[i] = CRGB(0,255,0);

leds[i+1] = CRGB(255,0,0);
leds[i+2] = CRGB(255,0,0);
leds[i+3] = CRGB(255,0,0);
leds[i+4] = CRGB(0,0,0);
leds[i+5] = CRGB(0,0,0);

leds[i+6] = CRGB(255, 140, 80);
leds[i+7] = CRGB(255, 140, 80);
leds[i+8] = CRGB(255, 140, 80);
leds[i+9] = CRGB(255, 140, 80);
leds[i+10] = CRGB(255, 140, 80);




Any help on understanding this would be great. Thanks!

When your for loop counts up to NUM_LEDS and you are plugging in the i value to something like [i+10] it would be trying write to a pixel that doesn’t exist. For example if i = 40 then 40+10 is beyond what you’ve defined as you last pixel number. Trying to write to pixels that don’t exist causes bad things to happen (overwrites bits of memory).