int inputPin = A2; // deklarasi pinout

int dataADC;
float NilaiConductivity;
float Nilaitds;

//Deklarasi rata- rata adc
const int numReadings = 20;

int readings[numReadings];  // pembacaan dari input analog
int readIndex = 0;          // indeks pembacaan saat ini
int total = 0;              // Total berjalan
int averageADC = 0;         // Rata- rata ADC


void setup() {
  Serial.begin (9600);

  for (int thisReading = 0; thisReading < numReadings; thisReading++) {
    readings[thisReading] = 0;
  }

}


void loop() {
  dataADC = analogRead(inputPin); //Baca Nilai ADC di pin A2
  Serial.print("Nilai ADC:  ");   Serial.print(dataADC);  Serial.println(" ADC     "); //Serial Monitor Nilai ADC

  // Pengurangan pembacaan terakhir:
  total = total - readings[readIndex];
  // pembacaan sensor:
  readings[readIndex] = analogRead(inputPin);
  // tambahkan pembacaan sensor ke total:
  total = total + readings[readIndex];
  // selanjutnya di array atau masuk himpunan:
  readIndex = readIndex + 1;

  // jika berada diakhir himpunan..
  if (readIndex >= numReadings) {
    // ...diulang dari awal:
    readIndex = 0;
  }

  // hasil rata2 ADC:
  averageADC = total / numReadings;
  Serial.print("Rata-rata Nilai ADC:  "); Serial.print(averageADC); Serial.println(" ADC     "); //Serial Monitor Nilai ADC

  NilaiConductivity = (0.2142 * averageADC) + 494.93; // regresi linear datasheet (uSiemens)
  Serial.print("Conductivity:  ");   Serial.print(NilaiConductivity);  Serial.println(" μS     "); //Serial Monitor Nilai Conductivity

  Nilaitds = (0.3417 * averageADC) + 281.08; // regresi linear datasheet (ppm)
  Serial.print("TDS:  ");   Serial.print(Nilaitds);  Serial.println(" μpm     "); //Serial Monitor Nilai TDS

  Serial.println();
  delay(100);

}