How do I turn on all the leds of a stirp at the same time?

Other Hardware LEDs and Multiplexing
1

Hi everyone,
I am using the led strip WS2812B.
I have 60 LED and I want to turn all of them on at the same time.
So far, I can turn on the first one if I do this:

#include <FastLED.h>
#define LED_PIN     7
#define NUM_LEDS    60
CRGB leds[NUM_LEDS];
void setup() {
  FastLED.addLeds<WS2812, LED_PIN, GRB>(leds, NUM_LEDS);
}
void loop() {
 
    leds[1] = CRGB ( 0, 0, 255);
    FastLED.show();

 delay(1000);
 
    leds[1] = CRGB ( 255, 0, 0);
    FastLED.show();
    
 delay(1000);
  
}

Or, I can turn them on one at a time if I do this:

#include <FastLED.h>
#define LED_PIN     7
#define NUM_LEDS    60
CRGB leds[NUM_LEDS];
void setup() {
  FastLED.addLeds<WS2812, LED_PIN, GRB>(leds, NUM_LEDS);
}
void loop() {
  for (int i = 0; i <= 59; i++) {
    leds[i] = CRGB ( 0, 0, 255);
    FastLED.show();

  }
 delay(1000);
     
  for (int i = 59; i >= 0; i--) {
    leds[i] = CRGB ( 255, 0, 0);
    FastLED.show();

  }
 delay(1000);
  
}

How do I turn all of them on at the same time?

Thank you in advance for your time

2

You can do this by moving FastLED.show() outside the for loops.

If you want to get rid of the for loops altogether, you can make leds a CRGBArray:

#include <FastLED.h>
#define LED_PIN     7
#define NUM_LEDS    60
CRGBArray<NUM_LEDS> leds;
void setup() {
  FastLED.addLeds<WS2812, LED_PIN, GRB>(leds, NUM_LEDS);
}
void loop() {
  leds = CRGB (0, 0, 255);
  FastLED.show();

  delay(1000);

  leds = CRGB (255, 0, 0);
  FastLED.show();

  delay(1000);

}

More information on that here:

3

Awesome, it worked =)

Also, thank you very much for the info page. Very useful.

4

You're welcome. I'm glad to hear it's working now. Enjoy!
Per