#include <ESP32Servo.h>

#define POTENTIOMETER_PIN  36  // ESP32 pin GPIO36 (ADC0) connected to Potentiometer pin
#define SERVO_PIN          26  // ESP32 pin GPIO26 connected to Servo Motor's pin
#define ANALOG_THRESHOLD   1000

Servo servo; // create servo object to control a servo
void setup() {
  // set the ADC attenuation to 11 dB (up to ~3.3V input)
  analogSetAttenuation(ADC_11db);
  servo.attach(SERVO_PIN);   // attaches the servo on pin 9 to the servo object
  servo.write(0);
}

void loop() {
  int analogValue = analogRead(POTENTIOMETER_PIN); // read the input on analog pin

  if (analogValue > ANALOG_THRESHOLD)
    servo.write(90); // rotate servo motor to 90 degree
  else
    servo.write(0);}  // rotate servo motor to 0 degree