//Pin declaration
const int SupplyVoltageSensorPin = A0;
const int ResistorVoltageSensorPin = A1;

//Variables declaration
float SupplyVoltageSensorRead;   //Supply Voltage read from analog input
float SupplyVoltageVal;          //Supply Voltage real Value
float ResistorVoltageSensorRead; //Fixed Resistor Voltage read from analog input
float ResistorVoltageVal;        //Fixed Resistor real Value
float ResistorVal;               //Unknow Resistor calculated value
float FixedResistor = 100;       //Fixed resistor of the voltage divider (2200 ohms)
float CurrentVal;                //Amount of current flowing in the circuit

void setup() {
  Serial.begin(9600);           //Initialize serial port
}



void loop() {

  //------------------------------------------
  //STEP 1 : Supply Voltage value reading and scaling
  //------------------------------------------

  for (int i = 1; i < 50; i++) {                                                //Calculate the average between 10 read to avoid value floating mistakes
    SupplyVoltageSensorRead += analogRead(SupplyVoltageSensorPin);              //Read the value from sensor
    delay(2);
  }
  SupplyVoltageSensorRead = SupplyVoltageSensorRead / 50.0;

  SupplyVoltageVal = SupplyVoltageSensorRead * (5.0 / 1024.0);       //Convert the read value in the real value (sensor read between 0 and 25V)


  //------------------------------------------
  //STEP 2 : Divider fixed resistor voltage value reading and scaling
  //------------------------------------------

  for (int i = 1; i < 50; i++) {                                                //Calculate the average between 10 read to avoid value floating mistakes
    ResistorVoltageSensorRead += analogRead(ResistorVoltageSensorPin);              //Read the value from sensor
    delay(2);
  }
  ResistorVoltageSensorRead = ResistorVoltageSensorRead / 50.0;

  ResistorVoltageVal = ResistorVoltageSensorRead * (5.0 / 1024.0);     //Convert the read value in the real value (sensor read between 0 and 25V)


  //------------------------------------------
  //STEP 3 : Resistor value calculating
  //------------------------------------------

  ResistorVal = ((SupplyVoltageVal - ResistorVoltageVal) * FixedResistor) / ResistorVoltageVal;              //Applying Voltage divider formula

  //------------------------------------------
  //STEP 4 : Current Calculating
  //------------------------------------------

  CurrentVal = SupplyVoltageVal / (FixedResistor + ResistorVal);        //Calculate the current using ohm's law
  CurrentVal = CurrentVal * 1000;                                       //Conversion in milliampere

  //------------------------------------------
  //STEP 5 : Print values on serial monitor
  //------------------------------------------
  Serial.print ("SUPPLY VOLTAGE: ");
  Serial.print (SupplyVoltageVal);
  Serial.println (" V");
  Serial.print ("FIXED RESISTOR VOLTAGE: ");
  Serial.print (  ResistorVoltageVal);
  Serial.println (" V");
  Serial.print ("RESISTENCE: ");
  Serial.print (ResistorVal);
  Serial.println (" Ohm");
  Serial.print ("CURRENT: ");
  Serial.print (CurrentVal);
  Serial.println (" mA");
  Serial.println();



  delay (2000);



}