hd108

#include <SPI.h>
#include <FastLED.h>
// Clock and data pins are whatever are SPI defaults for your board (SCK, MOSI)
// Arduino Mega 2560, Clock 52, Data 51

struct CRGB16;

#define NUM_LEDS 30

void oneFrame(uint16_t r, uint16_t g, uint16_t b);
void showLeds();

struct CRGB16 {
      uint16_t red;
      uint16_t green;
      uint16_t blue;
};

CRGB leds[NUM_LEDS];

uint16_t bpm = 15;

void setup() {
  SPI.begin();
}

void loop() {
  showLeds();
}

uint16_t maxB = 20000;

void showLeds() {
  SPI.beginTransaction(SPISettings(1000000, MSBFIRST, SPI_MODE3));
  // Start frame
  for (int i = 0; i <= 4; i++) {
    SPI.transfer16(0);
  }
  
  // LEDs
  for (int i = 0; i <= NUM_LEDS; i++) {
    uint16_t red = beatsin16(bpm+4,0,maxB + i * 1056);
    uint16_t green = beatsin16(bpm,0,maxB+ i * 1056,0,120);
    uint16_t blue = beatsin16(bpm+8,0,maxB+ i * 1056,0,210);
    oneFrame(red, green, blue);
  }

  // End Frame
  for (int i = 0; i <= 4; i++) {SPI.transfer16(0xFFFF);}
  SPI.endTransaction();

  delay(5);
}

void oneFrame(uint16_t r, uint16_t g, uint16_t b) {
    SPI.transfer(0xFF);  // Start of LED Frame & Brightness
    // SPI.transfer(0xFF);  // as (1)(5bit)(5bit)(5bit) brightnesses
    SPI.transfer(0x01);  // as (1)(5bit)(5bit)(5bit) brightnesses
    SPI.transfer16(r);  // RED (16-bit)
    SPI.transfer16(g);  // GREEN (16-bit)
    SPI.transfer16(b);  // BLUE (16-bit)
}