Use pots to control software PWM on Arduino, graph this on connected laptop

pwm_explorer.ino

/*
  PWM Explorer

  Connect pots to pins A0 and A1.
  Optionally connect LED to PIN 13 and grond (in series with 220 resistor).
 */

const int buttonPin = 2;
const int ledPin = LED_BUILTIN;

int lastTransitionTime = 0;
int nextTransitionValue = HIGH;

void setup() {
  Serial.begin(9600);
  pinMode(ledPin, OUTPUT);
  pinMode(buttonPin, INPUT);
}

void loop() {
  static long period = 100;
  static float dutyCycle = 0.5;
  static long lastSensorReadTime = -1;

  if (millis() - lastSensorReadTime > 250) {
    lastSensorReadTime = millis();

    period = analogRead(A0) * 1000L / 3 + 10;
    dutyCycle = analogRead(A1) / 1024.0;

    Serial.print(period);
    Serial.print(",");
    Serial.print(map(analogRead(A0), 0, 1000, 10, 300));
    Serial.print(",");
    Serial.println(dutyCycle);
  }

  // Use this instead of %, so that we don't get weird flickering patterns
  // when the pot is moved or drifts
  while (lastTransitionTime > micros() + period) {
    lastTransitionTime -= period;
  }
  int value = micros() - lastTransitionTime < dutyCycle * period ? HIGH : LOW;
//  if (micros() >= lastTransitionTime + ) {
//    int value = micros() % period < period * dutyCycle ? HIGH : LOW;
    digitalWrite(ledPin, value);
//  }
}