DIY Smart pH Meter Project

    /*
     * file DFRobot_PH.ino
     * @ https://github.com/DFRobot/DFRobot_PH
     *
     * This is the sample code for Gravity: Analog pH Sensor / Meter Kit V2, SKU:SEN0161-V2
     * In order to guarantee precision, a temperature sensor such as DS18B20 is needed, to execute automatic temperature compensation.
     * You can send commands in the serial monitor to execute the calibration.
     * Serial Commands:
     *   enterph -> enter the calibration mode
     *   calph   -> calibrate with the standard buffer solution, two buffer solutions(4.0 and 7.0) will be automaticlly recognized
     *   exitph  -> save the calibrated parameters and exit from calibration mode
     *
     * Copyright   [DFRobot](https://www.dfrobot.com), 2018
     * Copyright   GNU Lesser General Public License
     *
     * version  V1.0
     * date  2018-04
     */

    #include "DFRobot_PH.h"
    #include <EEPROM.h>

    #define PH_PIN A1
    float voltage,phValue,temperature = 25;
    DFRobot_PH ph;

    void setup()
    {
        Serial.begin(115200);
        ph.begin();
    }

    void loop()
    {
        static unsigned long timepoint = millis();
        if(millis()-timepoint>1000U){                  //time interval: 1s
            timepoint = millis();
            //temperature = readTemperature();         // read your temperature sensor to execute temperature compensation
            voltage = analogRead(PH_PIN)/1024.0*5000;  // read the voltage
            phValue = ph.readPH(voltage,temperature);  // convert voltage to pH with temperature compensation
            Serial.print("temperature:");
            Serial.print(temperature,1);
            Serial.print("^C  pH:");
            Serial.println(phValue,2);
        }
        ph.calibration(voltage,temperature);           // calibration process by Serail CMD
    }

    float readTemperature()
    {
      //add your code here to get the temperature from your temperature sensor
    }