Arduino LED effects example

This is an example on how to create a sketch as used in the Arduino – LEDStrip effects for NeoPixel and FastLED article.

In this example I assume we will be using the FastLED library, so make sure it is installed in your Arduino IDE’s library.

Step 1. Grab the proper starting code, so the “framework” for FastLED, which would be this:

#include "FastLED.h"
#define NUM_LEDS 60
CRGB leds[NUM_LEDS];
#define PIN 6
void setup()
{
  FastLED.addLeds<WS2811, PIN, GRB>(leds, NUM_LEDS).setCorrection( TypicalLEDStrip );
}

// *** REPLACE FROM HERE ***
void loop() {
  // ---> here we call the effect function <---
}
// ---> here we define the effect function <---
// *** REPLACE TO HERE ***

void showStrip() {
 #ifdef ADAFRUIT_NEOPIXEL_H
   // NeoPixel
   strip.show();
 #endif
 #ifndef ADAFRUIT_NEOPIXEL_H
   // FastLED
   FastLED.show();
 #endif
}
void setPixel(int Pixel, byte red, byte green, byte blue) {
 #ifdef ADAFRUIT_NEOPIXEL_H
   // NeoPixel
   strip.setPixelColor(Pixel, strip.Color(red, green, blue));
 #endif
 #ifndef ADAFRUIT_NEOPIXEL_H
   // FastLED
   leds[Pixel].r = red;
   leds[Pixel].g = green;
   leds[Pixel].b = blue;
 #endif
}
void setAll(byte red, byte green, byte blue) {
  for(int i = 0; i < NUM_LEDS; i++ ) {
    setPixel(i, red, green, blue);
  }
  showStrip();
}

Note the bolded section in the code that starts with “// *** REPLACE FROM HERE ***” and ends at “// *** REPLACE TO HERE ***“?

Replace the lines between these 2 with one of the effects you’d like to use.

So let’s say we want to use the “LEDStrip Effect – Fade In and Fade Out: Red, Green and Blue” effect. As you can see the suggested code would be:

void loop() {
  RGBLoop();
}
void RGBLoop(){
  for(int j = 0; j < 3; j++ ) {
    // Fade IN
    for(int k = 0; k < 256; k++) {
      switch(j) {
        case 0: setAll(k,0,0); break;
        case 1: setAll(0,k,0); break;
        case 2: setAll(0,0,k); break;
      }
      showStrip();
      delay(3);
    }
    // Fade OUT
    for(int k = 255; k >= 0; k--) {
      switch(j) {
        case 0: setAll(k,0,0); break;
        case 1: setAll(0,k,0); break;
        case 2: setAll(0,0,k); break;
      }
      showStrip();
      delay(3);
    }
  }
}

Now replace the text between the lines  “// *** REPLACE FROM HERE ***” and “// *** REPLACE TO HERE ***” with this code, and you’d get this (the bold section is what I’ve pasted into the “framework” code):

#include "FastLED.h"
#define NUM_LEDS 60
CRGB leds[NUM_LEDS];
#define PIN 6
void setup()
{
  FastLED.addLeds<WS2811, PIN, GRB>(leds, NUM_LEDS).setCorrection( TypicalLEDStrip );
}
// *** REPLACE FROM HERE ***
void loop() {
  RGBLoop();
}
void RGBLoop(){
  for(int j = 0; j < 3; j++ ) {
    // Fade IN
    for(int k = 0; k < 256; k++) {
      switch(j) {
        case 0: setAll(k,0,0); break;
        case 1: setAll(0,k,0); break;
        case 2: setAll(0,0,k); break;
      }
      showStrip();
      delay(3);
    }
    // Fade OUT
    for(int k = 255; k >= 0; k--) {
      switch(j) {
        case 0: setAll(k,0,0); break;
        case 1: setAll(0,k,0); break;
        case 2: setAll(0,0,k); break;
      }
      showStrip();
      delay(3);
    }
  }
}
// *** REPLACE TO HERE ***
void showStrip() {
 #ifdef ADAFRUIT_NEOPIXEL_H
   // NeoPixel
   strip.show();
 #endif
 #ifndef ADAFRUIT_NEOPIXEL_H
   // FastLED
   FastLED.show();
 #endif
}
void setPixel(int Pixel, byte red, byte green, byte blue) {
 #ifdef ADAFRUIT_NEOPIXEL_H
   // NeoPixel
   strip.setPixelColor(Pixel, strip.Color(red, green, blue));
 #endif
 #ifndef ADAFRUIT_NEOPIXEL_H
   // FastLED
   leds[Pixel].r = red;
   leds[Pixel].g = green;
   leds[Pixel].b = blue;
 #endif
}
void setAll(byte red, byte green, byte blue) {
  for(int i = 0; i < NUM_LEDS; i++ ) {
    setPixel(i, red, green, blue);
  }
  showStrip();
}

Now you can compile and run the code on your Arduino.
Don’t forget to set the correct number of LEDs (NUM_LEDS) and Pin (PIN) you’ve used.