#define SERIESRESISTOR 560    
#define SENSORPIN A0 

String waterState = "uninitialized";
String previousState = "uninitialized";

 
void setup(void) {
  Serial.begin(9600);
  Particle.publish("spotify_trigger");
}

 
void loop(void) {
  float reading;
 
  reading = analogRead(SENSORPIN);
 
  Serial.print("Analog reading "); 
  Serial.println(reading);
 
  // convert the value to resistance
  reading = (4095 / reading)  - 1;
  reading = SERIESRESISTOR / reading;
  Serial.print("Sensor resistance "); 
  Serial.println(reading);
  
  if (reading >= 1550) {
    waterState = "water_height_empty";
    } 
  else if ((reading < 1550) && (reading >= 1100)) {
    waterState = "water_height_filling";
    } 
  else if ((reading < 1100) && (reading >= 1050)) {
    waterState = "water_height_near";
    }
  else if ((reading < 1050) && (reading >= 900)) {
    waterState = "water_height_full";
    }
  else if (reading < 900) {
    waterState = "water_height_max";
    }
  else {
    waterState = "error";
    }  
  
  if (waterState != previousState) {
      Particle.publish(waterState);
      delay(750);
    }
  
  previousState = waterState;
  delay(1000);
}