/*

   Script to print PH to serial

   28/8/2015  Michael Ratcliffe  Mike@MichaelRatcliffe.com

          This program is free software: you can redistribute it and/or modify

    it under the terms of the GNU General Public License as published by

    the Free Software Foundation, either version 3 of the License, or

    (at your option) any later version.

    This program is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License

    along with this program.  If not, see <http://www.gnu.org/licenses/>.

    Parts:

    -Arduino - Uno/Mega

   -df Robot Ph Probe Kit [SKU:SEN0169] This is a great PH sensor compared to the ones ive had in the past

    See www.MichaelRatcliffe.com/Projects for a Pinout and user guide or consult the Zip you got this code from

*/

//*********************** User defined variables ****************************//

//pH meter Analog output to Arduino Analog Input 0

int PHPin =A15; 

//The calibration constant for the PH probe

float K=3.64;         

//The Ph we will be calibrating in

int Cal_pH=7;

//********************** End Of Recomended User Variables ******************//

//************** Some values for working out the ph*****************//

float Kn=0;

float phValue=0;

int i=0;

long reading=0;

long sum=0;

float average=0;

//******************** Setup Loop Runs Once ******************************//

void setup()

{

  Serial.begin(9600);

  startupinfo();

}

//******************** Main Loops runs Forver **************************//

void loop()

{

ReadPH();

PrintSerial();

Calabrate();

delay(1000);

}

//*************************Print Some useful startup info **************************//

void startupinfo(){

Serial.println("pH Probe Script for arduino");

Serial.println("Released under GNU by Michael Ratcliffe");

Serial.println("www.MichaelRatcliffe.com");

Serial.println("Element14 'Adapted_Greenhouse'");

Serial.println("Using DFRobot PH Probe Pro ");

Serial.println("How to Use:");

Serial.println("1:Place Probe into pH7 calibration fluid, open serial ");

Serial.println("2:Take Recomened cell constand and change it in the top of code");

Serial.println("3:Rinse Probe and place in pH4 calibration fluid");

Serial.println("4:Adjust potentiometer on pH meter shield until ph reading in serial is 4");

Serial.println("    ");

Serial.println("Thats it your calibrated and your readings are accurate!");

}

//*************************Take Ten Readings And Average ****************************//

void ReadPH(){

  i=1;

  sum=0;

  while(i<=10){

  reading=analogRead(PHPin);

  sum=sum+reading;

    delay(20);

    i++;

  }

average=sum/10.0;

//converting the average to PH 3.5 part convers mv to ph

phValue=average*K*5/1024; 

}

//*************************** Print useful data to moniter ****************************//

void PrintSerial(){

Serial.print("    pH:");

Serial.print(phValue);

Serial.println(" ");

}

//****************** Calculate a K value *********************************************//

void Calabrate(){

Kn=((Cal_pH*1024)/(average*5));

Serial.print("If pH 7, Cell Konstant=  :");

Serial.println(Kn);

};