Arduino - Control Servo 3 State

#include <SoftwareSerial.h>
#include <CytronServoShield.h>

SoftwareSerial mySerial(10, 11); // ON_BOARD_TX, ON_BOARD_RX
CytronServoShield servo;

int STATE = 0;  // 0, 1, 2  => 0 deg, 90 deg, 180 deg

void setup()
{

  pinMode(8, INPUT);

  Serial.begin(115200);
  mySerial.begin(9600);
  servo.init(&mySerial);

  servo.setStartAngle(ALL_CHANNELS, 0);
  servo.setChannel(ALL_CHANNELS, OFF);
  servo.setChannel(CHANNEL_1, ON);

  Serial.println("Init angle");
  servo.angle(CHANNEL_1, 0);
  while (servo.getAngle(CHANNEL_1) > 5)
  {
    delay(100);
  }
  delay(1000);

}

void loop()
{

  int sw  = digitalRead(8);
  if (sw == LOW)
  {

    servo.angle(CHANNEL_1, STATE * 90);

    STATE++;
    if(STATE > 2)
    {
      STATE = 0;
    }

    delay(1000);

  }

}