rewritten_ph_sensor_code.ino

#define PH_SENSOR_PIN 0  // pH meter Analog output connected to Arduino Analog Input 0

const int NUM_SAMPLES = 10;  // Number of samples to take for smoothing the value
const int NUM_SAMPLES_TO_AVERAGE = 6;  // Number of center samples to average

unsigned long int averageValue;  // Store the average value of the sensor feedback
float pHValue;  // Store the calculated pH value
int sensorReadings[NUM_SAMPLES];  // Array to store sensor readings
int tempValue;  // Temporary variable for sorting

void setup() {
  pinMode(13, OUTPUT);
  Serial.begin(9600);
  Serial.println("Ready");  // Test the serial monitor
}

void loop() {
  // Get 10 sample values from the sensor to smooth the readings
  for (int i = 0; i < NUM_SAMPLES; i++) {
    sensorReadings[i] = analogRead(PH_SENSOR_PIN);
    delay(10);  // Small delay between readings
  }

  // Sort the sensor readings from smallest to largest
  for (int i = 0; i < NUM_SAMPLES - 1; i++) {
    for (int j = i + 1; j < NUM_SAMPLES; j++) {
      if (sensorReadings[i] > sensorReadings[j]) {
        tempValue = sensorReadings[i];
        sensorReadings[i] = sensorReadings[j];
        sensorReadings[j] = tempValue;
      }
    }
  }

  // Calculate the average value of the center samples
  averageValue = 0;
  for (int i = 2; i < NUM_SAMPLES - 2; i++) {
    averageValue += sensorReadings[i];
  }
  averageValue /= NUM_SAMPLES_TO_AVERAGE;

  // Convert the analog value to pH
  pHValue = (float)averageValue * 5.0 / 1024;  // Convert the analog value to millivolts
  pHValue = 3.5 * pHValue;  // Convert millivolts to pH value

  // Print the pH value to the serial monitor
  Serial.print("pH: ");
  Serial.println(pHValue, 2);  // Print the pH value with 2 decimal places

  // Blink the LED
  digitalWrite(13, HIGH);
  delay(800);
  digitalWrite(13, LOW);
}