Example to receive serial commands for use with FastLED. FastLED itself is not implemented. This just replies the received command.

fastled_serial_control.ino

/*  Structure to receive 12 byte commands. 
 *  Protocol idea:
 *  https://drive.google.com/file/d/0B3Tn6oRmh71oS3FNQ2hsODVwS1E
 *  
 *  Processing program to send commands:
 *  https://gist.github.com/kasperkamperman/6c7c256f7042a3ca5118
 *
 *  Thanks to Daniel Garcia for the command structure example.
*/

// packing is necessary for Teensy and RFduino otherwise extra padding is added
// http://stackoverflow.com/questions/5473189/what-is-a-packed-structure-in-c
// typedef struct __attribute__((__packed__)) 

// added a padding byte instead after a tip from Daniel. Probably faster then packing.

struct Cmd { 

  uint8_t type;
  uint8_t typeId;
  uint8_t cmdId;
  uint8_t paddingByte;
  uint16_t cmdValue0;
  uint16_t cmdValue1; 
  uint16_t cmdValue2; 
  uint16_t cmdValue3;
}

Cmd aCmd;

void setup() {
  Serial.begin(57600); 
}
  
void loop() {

  // check if we have incoming data on our serialport
  while(Serial.available() > 0) {
    
    Serial.readBytes((char*) &aCmd,sizeof(Cmd));   

    sendReply();
  } 
}

// example for receiving the structure with Bluetooth RFDuino instead of through serial port.
// void RFduinoBLE_onReceive( char *data, int len) {
//   if(len>=sizeof(Cmd)) {
//     memcpy(&aCmd, &data[0], sizeof(Cmd));
//   }
//   sendReply();
// }

void sendReply() {

  // test if we received the values
  Serial.print(aCmd.type);
  Serial.print(",");
  Serial.print(aCmd.typeId);
  Serial.print(",");
  Serial.print(aCmd.cmdId);
  Serial.print(",");
  Serial.print(aCmd.cmdValue0);
  Serial.print(",");
  Serial.print(aCmd.cmdValue1);
  Serial.print(",");
  Serial.print(aCmd.cmdValue2);
  Serial.print(",");
  Serial.print(aCmd.cmdValue3);

  Serial.println();
}