int buttonstate=1;
void setup() {

pinMode(11, OUTPUT);
pinMode(12, OUTPUT);
pinMode(13, OUTPUT);

pinMode(10, INPUT_PULLUP);
Serial.begin(9600);
}

void loop() {
  int sensor = analogRead(A0);
  float voltage = sensor * (5.0/1023.0);
 Serial.println(sensor);
 Serial.println(voltage);
 delay(200);

if(voltage>2.5) {
  digitalWrite(11, LOW);
}else {
  digitalWrite(11, HIGH); 

}
buttonstate = digitalRead(10);
if (buttonstate == HIGH) {
digitalWrite(12, LOW);
}else {
  digitalWrite(12, HIGH);
}
}