/*
  by Dileepa Jayawardena
  ii.lk
*/

#define ROTARY_ANGLE_SENSOR A0
#define ADC_REF 5//reference voltage of ADC is 5v.If the Vcc switch on the seeeduino
#define GROVE_VCC 5//VCC of the grove interface is normally 5v
#define FULL_ANGLE 300//full value of the rotary angle is 300 degrees
void setup()
{
  Serial.begin(9600);
}

void loop()
{
  int degrees;
  degrees = getDegree();
  Serial.println(degrees);


  delay(500);
}


/************************************************************************/
/*Function: Get the angle between the mark and the starting position    */
/*Parameter:-void                                                       */
/*Return:   -int,the range of degrees is 0~300                          */
int getDegree()
{
  int sensor_value = analogRead(ROTARY_ANGLE_SENSOR);
  float voltage;
  voltage = (float)sensor_value * ADC_REF / 1023;
  float degrees = (voltage * FULL_ANGLE) / GROVE_VCC;
  return degrees;
}