nwmedia-c262-lab2.ino

#define BAUD_RATE 9600
#define DELIMITER '\n'
#define SAMPLING_RATE 100

#define LED_RED 9
#define LED_GREEN 10
#define LED_BLUE 11

int t = 0;
int dt = 1;
int elapse = 1;
uint8_t rgb[3];

void setup() {
  pinMode(LED_RED, OUTPUT);
  pinMode(LED_GREEN, OUTPUT);
  pinMode(LED_BLUE, OUTPUT);
  Serial.begin(BAUD_RATE);
  Serial.println("READY");
}

void loop() {
  if (Serial.available()) {
    int n = Serial.readBytesUntil(DELIMITER, rgb, sizeof(rgb));
  }
  if (elapse <= 0) {
    int x = rand();
    if (x % 3 == 0) {
      dt = x % 2 + 2;
    } else {
      dt = 1;
    }
    elapse = SAMPLING_RATE / dt;
  } else {
    --elapse;
  }
  t = (t + dt) % SAMPLING_RATE;
  double strength = 0.75 + 0.25 * sin(2 * PI * t / SAMPLING_RATE);
  analogWrite(LED_RED, round(strength * rgb[0]));
  analogWrite(LED_GREEN, round(strength * rgb[1]));
  analogWrite(LED_BLUE, round(strength * rgb[2]));
  delay(20);
}