Chainable RGB led

Install the Grove - Chainable RGB LED library

Copy/paste this fade example in to your Arduino Sketch:

#include <ChainableLED.h>

#define NUM_LEDS  1
ChainableLED leds(D6, D7, NUM_LEDS);  // (CLOCK_IN, DATA_IN, LED_NUMBER)

int brightness = 0;    // how bright the LED is
int fadeAmount = 5;    // how many points to fade the LED by

void setup() {
}

void loop() {
  // set the brightness of the led (LED_NUMBER, RED, GREEN, BLUE)
  leds.setColorRGB(0, brightness, 0, 0); 

  // change the brightness for next time through the loop:
  brightness = brightness + fadeAmount;

  // reverse the direction of the fading at the ends of the fade:
  if (brightness <= 0 || brightness >= 255) {
    fadeAmount = -fadeAmount;
  }
  // wait for 30 milliseconds to see the dimming effect
  delay(30);
}

References

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