Servo myservo;  // create servo object to control a servo
                // a maximum of eight servo objects can be created

  // variable to store the servo position

int startpos = 165;
int pos = startpos;  
int endpos = 35;

int drink = 0;

void setup() {
    Serial.begin(9600);
    myservo.attach(D4);   // attach the servo on the D0 pin to the servo object
    myservo.write(startpos);    // test the servo by moving it to 25°
    pinMode(D5, INPUT);
    
    attachInterrupt(D5, did_drink, CHANGE);
}

void loop() {
    // begin API calls on loop, parse and raise or lower servo arm
    if (pos > endpos){
        pos--;
        myservo.write(pos); 
    }

    delay(100);
}

void did_drink() {
    pos = startpos;
    myservo.write(pos); 
    
}