Arduino byte beats, https://youtu.be/gng2Gb0DHe4

arduino_bytebeats.c

/*
  Byte beats.

  More info: http://canonical.org/~kragen/bytebeat/

  Video: https://www.youtube.com/watch?v=gng2Gb0DHe4

  Circuit:
  - 8 ohm speaker on digital pin 2
    - max 0.25 W, 250 ohm resistor to keep current low
  
  My first meaningful Arduino project, beyond LED "hello world".
  
  I tried to get the classic byte beats working, but unsuccessfully.
  So I tried to make some my own formulas.
  And they don't sound bad... :)
*/

const int SPEAKER_PIN = 2;

//int t = 0;

void setup() {
  for (int t = 0; t < 100000; t++) {
  //  16-bit value
//  int value = ((t<<1)^((t<<1)+(t>>7)&t>>12))|t>>(4-(1^7&(t>>19)))|t>>7;
//good:
//  int value = (t<<1) * 2 + (t>>2) | 21^t >> t | t>>3;
//  value = (value << 3) % 256;

//  int value = ((t<<1)^((t<<1)+(t>>7)&t>>12))|t>>(4-(1^7&(t>>19)))|t>>7;

  // ta, tada, ta
//  int value = ((t << 4) ^ (t << 5) | (t << 6)) % 256;

  // funny!
//  int value = ((t << 1) ^ ((t << 5) | (t >> 2) | (t >> 3))) % 256;
  
  // int value = (((t << 4) | (t << 3)) ^ ((t << 5) | (t >> 2) | (t >> 3))) % 256;

//  int value = ((t << 1) + (t >> 1)) % 256;

  // good rythm!
  int value = (t << (t >> 4)) % 256;

  // crystal block effect
//  int value = (t << (t >> 8)) % 256;

//  int value = ((t << (t >> 8)) | (t << 1)) % 256;

//  int value = ((t << (t >> 8)) | (t << (t << 1))) % 256;

  // fall
//  int value = ((t << (t >> 8)) | (t << (t << 1))) % 256;

//    int value = (t << (t*2 + t)) % 256;

  // mole
//  int value = (t << (t/3 + t)) % 256;
  
    analogWrite(SPEAKER_PIN, value);
    delayMicroseconds(125);
    t += 1;
  }
}

void loop() {

}