#include <ESPservo.h>
Servo myServo;

// Pin definitions
int buttonA = 12;   // Start button
int buttonB = 14;   // Stop button
int servoPin = 18;

// Variables
bool servoRunning = false;
int angle = 0;

void setup() {

  Serial.begin(115200);

  // Attach servo
  myServo.attach(servoPin);

  // Set button pins
  pinMode(buttonA, INPUT_PULLUP);
  pinMode(buttonB, INPUT_PULLUP);

}

void loop() {

  // Read buttons
  if (digitalRead(buttonA) == LOW) {
    servoRunning = true;   // Start servo
    delay(200);            // Debounce
  }

  if (digitalRead(buttonB) == LOW) {
    servoRunning = false;  // Stop servo
    delay(200);            // Debounce
  }

  // Servo running condition
  if (servoRunning == true) {

    // Sweep motion
    for (angle = 0; angle <= 180; angle += 5) {
      myServo.write(angle);
      delay(50);

      // Stop immediately if Button B pressed
      if (digitalRead(buttonB) == LOW) {
        servoRunning = false;
        break;
      }
    }

    for (angle = 180; angle >= 0; angle -= 5) {
      myServo.write(angle);
      delay(50);

      // Stop immediately if Button B pressed
      if (digitalRead(buttonB) == LOW) {
        servoRunning = false;
        break;
      }
    }

  }

}