README.md

#define PC_BAUDRATE 9600 #define BLUETOOTH_BAUDRATE 9600 #define trigPin 13 #define echoPin 12 #define led 11 #define led2 10

#include <SoftwareSerial.h>

/*WaterLevel / Distance */ char incoming_value; char outgoing_value; int prev = -100; int pHPrev = -1000; const int buzzer = 9; //buzzer to arduino pin 9

/PH/ #define SensorPin A0 //pH meter Analog output to Arduino Analog Input 0 #define Offset 0.00 //deviation compensate unsigned long int avgValue; //Store the average value of the sensor feedback

/Create Variables for output/ String waterLevelString = String("WaterLevel:"); String outPutString = String();

String pHString = String("PH:");

SoftwareSerial SerialBT(4, 5); // RX, TX

void setup() { Serial.begin(PC_BAUDRATE); SerialBT.begin(BLUETOOTH_BAUDRATE);

/* Distance Sensor setup */
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);
pinMode(led, OUTPUT);
pinMode(led2, OUTPUT);
pinMode(buzzer, OUTPUT); // Set buzzer - pin 9 as an output

}

void loop() { // waterph long duration, distance; digitalWrite(trigPin, LOW); // Added this line delayMicroseconds(2); // Added this line digitalWrite(trigPin, HIGH); // delayMicroseconds(1000); - Removed this line delayMicroseconds(10); // Added this line digitalWrite(trigPin, LOW); duration = pulseIn(echoPin, HIGH); distance = (duration/2) / 29.1;

if (distance < 4) 
{  // This is where the LED On/Off happens
    digitalWrite(led,HIGH); // When the Red condition is met, the Green LED should turn off
    digitalWrite(led2,LOW);
    tone(buzzer, 1000); // Send 1KHz sound signal...
    delay(1000);        // ...for 1 sec
    noTone(buzzer);     // Stop sound...
    delay(100);        // ...for 1sec
}
else 
{
    digitalWrite(led,LOW);
    digitalWrite(led2,HIGH);
}

if (distance >= 200 || distance <= 0)
{
    Serial.println("Out of range");
}
else 
{
    if (distance != prev || prev == -100)
    {
        outPutString = waterLevelString + distance;
        
        Serial.println(outPutString);
        SerialBT.println(outPutString);
        
        prev = distance;
    }
}


// PH
int buf[10]; //buffer for read analog
for (int i = 0; i < 10; i++) //Get 10 sample value from the sensor for smooth the value
{
    buf[i] = analogRead(SensorPin);
    delay(10);
}
for (int i = 0; i < 9; i++) //sort the analog from small to large
{
    for (int j = i + 1; j < 10; j++) {
        if (buf[i] > buf[j]) {
            int temp = buf[i];
            buf[i] = buf[j];
            buf[j] = temp;
        }
    }
}

avgValue = 0;
for (int i = 2; i < 8; i++) //take the average value of 6 center sample
{
  avgValue += buf[i];
}

float phValue = (float) avgValue * 3.8 / 1030 / 6; //convert the analog into millivolt
phValue = 3.3 * phValue + Offset; //convert the millivolt into pH value

if (phValue != pHPrev || pHPrev == -1000)
{
    outPutString = pHString + phValue;
            
    Serial.println(outPutString);
    SerialBT.println(outPutString);
}
delay(1000);

}