// https://forum.arduino.cc/t/testing-millis-with-servos-and-experiencing-odd-behavior/1092322
// https://wokwi.com/projects/357135312156712961

# include <Servo.h>

Servo myServo;

// I changed this for the moment:

unsigned long MOVING_TIME = 2500;
unsigned long moveStartTime;

int startAngle = 0;
int stopAngle  = 180;

void setup() {
  Serial.begin(115200);
  Serial.println("Servo World!\n");

  myServo.attach(9);

  myServo.write(stopAngle);
  delay(1000);

  moveStartTime = millis(); // start moving
}

void loop() {
  unsigned long currentMillis = millis();

  unsigned long progress = currentMillis - moveStartTime;

  if (progress <= MOVING_TIME) {
    long angle = map(progress, 0, MOVING_TIME, stopAngle, startAngle);
    myServo.write(angle); 

// reporting section
    static unsigned long timeOfLastReport;
    static int lastReportedAngle = -1;

    if (lastReportedAngle != angle) {   // just print if the new issued angle is different
      Serial.print(currentMillis - timeOfLastReport);
      Serial.print(" ms later told servo to ");
      Serial.println(angle);

      timeOfLastReport = currentMillis;
      lastReportedAngle = angle;
    }
//  end reporting section - remove it when you dare

  }
}