Generating waveforms with Arduino Uno

/**************************************************************************************
  ARDUINO UNO - WAVEFORM GENERATOR AND FILTER - JULIO CESAR - JCR - 09/21
 **************************************************************************************/
/* Instructions: connect Arduino Uno to PC or Notebook via USB cable, choose one of the functions to be plotted
  (SAW, SQR, FILTER and SINE), load the sketch in Arduino Uno, go to the Tools menu and open the Serial Plotter. */

byte filter;
byte saw;
byte sqr;
int sine;
int angle;

void setup() {
  Serial.begin(19200);
}

void loop() {
  delay(5);
  saw_square_gen();
  filter_lowpass();
  sine_gen();

  //Comment out one the below Serial.println() waveform you want to plot (one at a time):
  //Serial.println(saw);
  //Serial.println(sqr);
  //Serial.println(filter);
  Serial.println(sine);
}

void saw_square_gen() {     //SAW & SQUARE WAVE GEN
  saw = saw + 1;
  if (saw > 127 && saw < 256) sqr = 255; else sqr = 1;
}

void sine_gen() {            //SINE WAVE GEN
  angle = angle + 1;  if (angle > 360) angle = 0;
  //sine = 50 * sin((angle * PI / 180));
  sine = 50 * sin(angle * 0.0174532925);
  //sine = abs(sine);
}

void filter_lowpass() {      //DIGITAL FILTER
  filter = filter * 0.9 + sqr * 0.1;
}