PlatformIO_ESP32_ServoDemo/src/main.cpp

#include <Arduino.h>
#include <Servo.h>

static const int servoPin = 4;

Servo servo1;

void setup() {
    Serial.begin(115200);
    servo1.attach(servoPin);
}

void loop() {
    for(int posDegrees = 0; posDegrees <= 180; posDegrees++) {
        servo1.write(posDegrees);
        Serial.println(posDegrees);
        delay(20);
    }

    for(int posDegrees = 180; posDegrees >= 0; posDegrees--) {
        servo1.write(posDegrees);
        Serial.println(posDegrees);
        delay(20);
    }
}