/*
 * Hydroponics system monitor
 * J. Devine
 * Runs on Arduino Pro 5V
 * Sensors:
 * DFRobot pHmeter V1.1
 * Waterproof DS18B20 water temperature sensor
 * TMP36 air temperature sensor
 * HC-SR04 distance sensor (for water level..)
 * A european two pin plug for EC measurements
 * Output in CSV; no error handling yet
 * write out all the results in the following format:
 * uptime (ms),water level (cm), pH, pH Voltage, water temp (degrees C), air temp (degrees C), RC, EC, PPM
 * 
 * This code is entirely based on some awesome examples, re-worked for this application
 * The internal pullup library is needed to avoid an external 4.7k resistor on the DS18B20
 * Great blog entry by josh levine @bigjoshlevine - Thanks! I was thinking EXACTLY the same thing
 * https://wp.josh.com/2014/06/23/no-external-pull-up-needed-for-ds18b20-temp-sensor/
 * 
 * PPM code
 * Modified from ElCheapo Arduino EC-PPM measurments
 * 28/8/2015  Michael Ratcliffe  Mike@MichaelRatcliffe.com
 * 
 * Pinouts:
 * 
 * Pin 10 - DS18B20 data pin
 * Pin 12 - HC-SR04 Trig
 * Pin 13 - HC-SR04 Echo
 * Pin A2 - pH Meter V1.1 data (DF Robot breakout)
 * Pin A3 - TMP36 data pin
 * Pin D4 - EC/PPM Power
 * Pin A1 - EC/PPM Pin
 * Pin A3 - EC/PPM Ground
 * 
 * Licensed under GPL V3. Read the license here:
 * https://www.gnu.org/licenses/gpl-3.0.en.html
 * 
*/
#define SensorPin A2            //pH meter Analog output to Arduino Analog Input 2
#define Offset 0.00            //deviation compensate
//#define LED 13
#define samplingInterval 20
#define printInterval 800
#define ArrayLenth  40    //times of collection
int pHArray[ArrayLenth];   //Store the average value of the sensor feedback
int pHArrayIndex=0;    

//PPM code
// Modified from ElCheapo Arduino EC-PPM measurments
//  28/8/2015  Michael Ratcliffe  Mike@MichaelRatcliffe.com
int R1= 400;
int Ra=25; //Resistance of powering Pins
int ECPin= A1;
int ECGround=A3;
int ECPower = 4;

//User variales for the PPM/EC measurement
float PPMconversion=0.7;
float TemperatureCoef = 0.019; //this changes depending on what chemical we are measuring
float K=2.85;
//Fixed variables
//float Temperature=10; variable substituted for Ftemp in this code
float EC=0;
float EC25 =0;
int ppm =0;
float raw= 0;
float Vin= 5;
float Vdrop= 0;
float Rc= 0;
float buffer=0;

//water temperature
float Ftemp=10;

 

// DS18S20 Temperature chip i/o
#include <OneWire.h> //this is the onewire version with the pullup high.

OneWire ds(10);  // on pin 10

int echopin = 13;
int trigpin = 12;
int vcc = 11;
long duration, distance;


//tmp36 readout
int sensorPin = 0;

void setup(void)
{
  //PPM Measurement setup code
  pinMode(ECPin,INPUT);
  pinMode(ECPower,OUTPUT);//Setting pin for sourcing current
  pinMode(ECGround,OUTPUT);//setting pin for sinking current
  digitalWrite(ECGround,LOW);//We can leave the ground connected permanantly
 
  delay(100);// gives sensor time to settle
  delay(100);
  //** Adding Digital Pin Resistance to [25 ohm] to the static Resistor *********//
  // Consule Read-Me for Why, or just accept it as true
  R1=(R1+Ra);// Taking into acount Powering Pin Resitance


  
  pinMode(echopin, INPUT);     
  pinMode(trigpin, OUTPUT);     
//  pinMode(LED,OUTPUT);  
  Serial.begin(9600);  
//  Serial.println("pH meter experiment!");    //Test the serial monitor
}
void loop(void)
{
  static unsigned long samplingTime = millis();
  static unsigned long printTime = millis();
  static float pHValue,voltage;
  if(millis()-samplingTime > samplingInterval)
  {
      pHArray[pHArrayIndex++]=analogRead(SensorPin);
      if(pHArrayIndex==ArrayLenth)pHArrayIndex=0;
      voltage = avergearray(pHArray, ArrayLenth)*5.0/1024;
      pHValue = 3.5*voltage+Offset;
      samplingTime=millis();
  }
  if(millis() - printTime > printInterval)   //Every 800 milliseconds, print a numerical, convert the state of the LED indicator
  {
//  Serial.print("Voltage:");
//        Serial.print(voltage,2);
//        Serial.print("    pH value: ");
//  Serial.println(pHValue,2);
//        digitalWrite(LED,digitalRead(LED)^1);
        printTime=millis();

  }

  
  byte i;
  byte present = 0;
  byte data[12];
  byte addr[8];
  int Temp;

  ds.reset_search();
  if ( !ds.search(addr)) {
  //    Serial.print("No more addresses.\n");
      ds.reset_search();
      return;
  }

//  Serial.print("R=");
  for( i = 0; i < 8; i++) {
//    Serial.print(addr[i], HEX);
//    Serial.print(" ");
  }

  if ( OneWire::crc8( addr, 7) != addr[7]) {
//      Serial.print("CRC is not valid!\n");
      return;
  }

  if ( addr[0] == 0x10) {
//      Serial.print("Device is a DS18S20 family device.\n");
  }
  else if ( addr[0] == 0x28) {
//      Serial.print("Device is a DS18B20 family device.\n");
  }
  else {
//      Serial.print("Device family is not recognized: 0x");
//      Serial.println(addr[0],HEX);
      return;
  }

  ds.reset();
  ds.select(addr);
  ds.write(0x44,1);         // start conversion, with parasite power on at the end

  delay(1000);     // maybe 750ms is enough, maybe not
  // we might do a ds.depower() here, but the reset will take care of it.

  present = ds.reset();
  ds.select(addr);    
  ds.write(0xBE);         // Read Scratchpad

//  Serial.print("P=");
//  Serial.print(present,HEX);
//  Serial.print(" ");
  for ( i = 0; i < 9; i++) {           // we need 9 bytes
    data[i] = ds.read();
//    Serial.print(data[i], HEX);
//    Serial.print(" ");
  }
 Temp=(data[1]<<8)+data[0];//take the two bytes from the response relating to temperature
//  Serial.println("One, then 0");
//  Serial.println(data[1]); //msb
//  Serial.println(data[0]); //lsb
 //Temp=Temp>>4;//divide by 16 to get pure celcius readout
Ftemp =(Temp * 0.0625);
 //next line is Fahrenheit conversion
 //Temp=Temp*1.8+32; // comment this line out to get celcius
 
// Serial.print("T=");//output the temperature to serial port
// Serial.print(Temp);
//   Serial.print("  ");

//Serial.print(" fT=");//output the temperature to serial port
// Serial.print(Ftemp);
//   Serial.print("  ");
  
//  Serial.print(" CRC=");
//  Serial.print( OneWire::crc8( data, 8), HEX);
//  Serial.println();


//getting the voltage reading from the temperature sensor
 int reading = analogRead(sensorPin);  
 
 // converting that reading to voltage, for 3.3v arduino use 3.3
 float ATvoltage = reading * 5.0;
 ATvoltage /= 1024.0; 
 
 // print out the voltage
 //Serial.print(ATvoltage); Serial.println(" volts");
 
 // now print out the temperature
 float temperatureC = (ATvoltage - 0.5) * 100 ;  //converting from 10 mv per degree wit 500 mV offset
                                               //to degrees ((voltage - 500mV) times 100)
 //Serial.print(temperatureC); Serial.println(" degrees C");
 
 // now convert to Fahrenheit
 //float temperatureF = (temperatureC * 9.0 / 5.0) + 32.0;
 //Serial.print(temperatureF); Serial.println(" degrees F");
 
 //delay(1000);



  digitalWrite(trigpin, LOW);  // Added this line

  delayMicroseconds(4); // Added this line

  digitalWrite(trigpin, HIGH);

  delayMicroseconds(20); // Added this line

  digitalWrite(trigpin, LOW);

  duration = pulseIn(echopin, HIGH);

  distance = (duration/2) / 29.1;

  Serial.print(millis());
  Serial.print(';');
  Serial.print(distance);

 // if (distance >= 200 || distance <= 0){

   // Serial.println("Out of range");

  //}

  //else {

    //Serial.print(distance);

    //Serial.println(" cm");

 // }

  //delay(500);


//write out all the results in the following format
// uptime (ms),water level (cm), pH, pH Voltage, water temp (degrees C), air temp (degrees C), RC, EC, PPM



Serial.print(';');
Serial.print(pHValue,2);
Serial.print(';');
Serial.print(voltage,2);
Serial.print(';');
Serial.print(Ftemp);
Serial.print(';');
Serial.print(temperatureC);
Serial.print(';');
GetEC();
PrintReadings();    
delay(5000);
}




double avergearray(int* arr, int number){
  int i;
  int max,min;
  double avg;
  long amount=0;
  if(number<=0){
    Serial.println("Error number for the array to avraging!/n");
    return 0;
  }
  if(number<5){   //less than 5, calculated directly statistics
    for(i=0;i<number;i++){
      amount+=arr[i];
    }
    avg = amount/number;
    return avg;
  }else{
    if(arr[0]<arr[1]){
      min = arr[0];max=arr[1];
    }
    else{
      min=arr[1];max=arr[0];
    }
    for(i=2;i<number;i++){
      if(arr[i]<min){
        amount+=min;        //arr<min
        min=arr[i];
      }else {
        if(arr[i]>max){
          amount+=max;    //arr>max
          max=arr[i];
        }else{
          amount+=arr[i]; //min<=arr<=max
        }
      }//if
    }//for
    avg = (double)amount/(number-2);
  }//if
  return avg;
}

void GetEC(){
 
 
 
//************Estimates Resistance of Liquid ****************//
digitalWrite(ECPower,HIGH);
raw= analogRead(ECPin);
raw= analogRead(ECPin);// This is not a mistake, First reading will be low beause if charged a capacitor
digitalWrite(ECPower,LOW);
 
 
 
 
//***************** Converts to EC **************************//
Vdrop= (Vin*raw)/1024.0;
Rc=(Vdrop*R1)/(Vin-Vdrop);
Rc=Rc-Ra; //acounting for Digital Pin Resitance
EC = 1000/(Rc*K);
 
 
//*************Compensating For Temperaure********************//
EC25  =  EC/ (1+ TemperatureCoef*(Ftemp-25.0));
ppm=(EC25)*(PPMconversion*1000);
 
 
;}
//************************** End OF EC Function ***************************//
 
 
 
 
//***This Loop Is called From Main Loop- Prints to serial usefull info ***//
void PrintReadings(){
//Serial.print("Rc: ");
Serial.print(Rc);
Serial.print(';');
//Serial.print(" EC: ");
Serial.print(EC25);
Serial.print(';');
//Serial.print(" Simens  ");
Serial.print(ppm);
//Serial.print(" ppm  "); 
Serial.println(';');
}