FastLED blend

/* blend

By: Andrew Tuline

Date: June, 2015

Here's a simple method to blend between a couple of colours across a strand of LED's. It doesn't really make good use of
the individually addressable aspect of these LED's.

It uses FastLED's:

- blend() function to blend between two colours
- sin8() function to provide a smooth varying input to blend().

*/

#include "FastLED.h"                                          // FastLED library. Preferably the latest copy of FastLED 2.1.

// Fixed global definitions.
#define LED_DT 12                                             // Data pin to connect to the strip.
#define LED_CK 11
#define COLOR_ORDER BGR                                       // Are they RGB, GRB or what??
#define LED_TYPE APA102                                       // Don't forget to change LEDS.addLeds
#define NUM_LEDS 20                                           // Number of LED's.

// Initialize changeable global variables.
uint8_t max_bright = 16;                                      // Overall brightness definition. It can be changed on the fly.

struct CRGB leds[NUM_LEDS];                                   // Initialize our LED array.

// Define variables used by the sequence.
uint8_t thisdelay = 25;                                        // Our delay.
int mysine=0;                                                  // Input for a sinewave. Saves on counting up/down.


void setup() {
  delay(1000);                                                 // Power-up safety delay or something like that.
  Serial.begin(57600);
  LEDS.addLeds<LED_TYPE, LED_DT, LED_CK, COLOR_ORDER>(leds, NUM_LEDS);  // Use this for WS2801 or APA102
  FastLED.setBrightness(max_bright);
} // setup()

void loop () {
  blendme();
  FastLED.show();
  delay(thisdelay);
  mysine++;
} // loop()


void blendme() {
  for (uint8_t i = 0; i<NUM_LEDS; i++) {

    leds[i] = blend(CRGB::Red, CRGB::Blue, sin8(mysine));

//  If you forgot about the blend function, you can always use this instead:
//  leds[i].r = sin8(mysine);
//  leds[i].b = 255 - sin8(mysine);
  }
} // blendme()