#define BUF_LEN 64

int red_pin= 17;
int green_pin = 19;
int blue_pin = 18;

char read_buffer[BUF_LEN];
int n_buffer = 0;

void setup() {
  pinMode(red_pin, OUTPUT);
  pinMode(green_pin, OUTPUT);
  pinMode(blue_pin, OUTPUT);
  SerialUSB.begin(115200);
}


void parse_buffer() {
  int red_value = 0;
  int green_value = 0;
  int blue_value = 0;

  SerialUSB.println("buffer:");
  SerialUSB.println(read_buffer);
  if (sscanf(read_buffer, "[%d,%d,%d]", &red_value, &green_value, &blue_value) == 3) {
    RGB_color(red_value, green_value, blue_value);
  }
}

void loop() {
  if (SerialUSB.available()) {
    char c = SerialUSB.read();

    if (c == '\n') {
      read_buffer[n_buffer] = '\0'; // null terminator
      parse_buffer();
      n_buffer = 0;
    } else {
      read_buffer[n_buffer] = c;
      n_buffer++;
    }
  }
}

void RGB_color(int red_value, int green_value, int blue_value) {
  analogWrite(red_pin, red_value);
  analogWrite(green_pin, green_value);
  analogWrite(blue_pin, blue_value);
}