#include <Servo.h>

Servo servo;
#define relayAL 9
#define servoPWM 11
#define buttonPIN 10

void setup() {
  Serial.begin(115200);
  servo.attach(servoPWM);
  servo.write(0); // Default
  pinMode(buttonPIN, INPUT_PULLUP);
  pinMode(relayAL, OUTPUT);
}

uint8_t angle = 0;
void loop() {
  bool buttonState = !digitalRead(buttonPIN);
  if(buttonState && angle <= 180){
    angle += 20; // Add 20
    delay(250);
  } else if (angle > 180) {
    angle = 0; // Reset
    delay(250);
  }

  if (angle == 180) {
    digitalWrite(relayAL, LOW);
  } else {
    digitalWrite(relayAL, HIGH);
  }

  servo.write(angle);
}