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Arduino Forum nested for loops in fast_leds for programming ws2812 strips
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Forum Thread Details
  • State Not Answered
  • Replies 2 replies
  • Subscribers 389 subscribers
  • Views 545 views
  • Users 0 members are here
  • fastled
  • strip
  • programming
  • ws2811
  • ws2812b
  • ws2812
  • leds
  • arduino
Related

nested for loops in fast_leds for programming ws2812 strips

Former Member
Former Member over 10 years ago

hi, im trying to get this led strip to fade up and down while switching colors. im trying to program 2 colors at once inside a for loop and its not working. it fades up n down to blue but then i nest a for loop inside another for loop so i can change 2 parameters of the RGB and it switches to the color but doesnt fade into it slowly. it actually will flash to pure green first then fades into its set color: a cool blue, mix of green n blue that i set. so it seems like it is fading but not how I intended. can someone help me understand this?

 

everything works but the last for loop is screwy when i try to fade a mikx of B and G. (j and z)

void loop() {

 

  for( int j = 0; j < 200; j++) {

    for (int i = 0; i < NUM_LEDS; i++) {

  //blue

  leds[i] = CRGB(0,0,j);

  } 

  FastLED.show();

  delay(20);

 

  }

for(int j = 200; j > 0; j--) {

   for (int i = 0; i < NUM_LEDS; i++) {

     leds[i] = CRGB(0,0,j);

}

FastLED.show();

   delay(20);

}

 

for(int j = 0; j < 200; j++) {

   for(int z = 0; z < 200; z++){       //---My line I added to try changing G and B colors at the same time

for(int i = 0; i < NUM_LEDS; i++){

     leds[i]=CRGB(0,z,j);

}

   }

 

FastLED.show();

   delay(30);

}

}

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  • gadget.iom
    gadget.iom over 10 years ago +1
    Are you looking to bring up green and blue together? If so, try changing the following line: leds[i]=CRGB(0,z,j); to: leds[i]=CRGB(0,j,j); and removing the z loop you added.
  • gadget.iom
    0 gadget.iom over 10 years ago

    Are you looking to bring up green and blue together?

    If so, try changing the following line:

    leds[i]=CRGB(0,z,j);

    to:

    leds[i]=CRGB(0,j,j);

    and removing the z loop you added.

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  • gadget.iom
    0 gadget.iom over 10 years ago in reply to gadget.iom

    In the programs current workflow, you are going to be bringing the green to an almost instant full using the Z loop, because there is no delay instruction inside that loop and you are not calling the FastLED.show() instruction until that loop has completed.

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