#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Keypad.h>



//-----------------------------  Pins & Connections ------------------------------------
//------------------------------------------------./Relay + Keypad ---------------------
int   valve           =   12;//(Water Valve & Pump) Relay <IN2> to Arduino <Pin 12>

byte  sensorPin       =   3;//  Water Flow Sensor <Yellow Wire> to Arduino Mega 2560 <Pin 3>

byte rowPins[4] = {22, 24, 26, 28}; //Rows 0 to 3

byte colPins[4] = {30, 32, 34, 36}; //Columns 0 to 3

//--------------------------------------------------------------------------------------


//--------------------------  2004A (0x3F) 20x4 LCD Screen -----------------------------
//---------------------------------------------./Global Variables-----------------------

// initialize the library with the numbers of the interface pins
//                    addr,en,rw,rs,d4,d5,d6,d7,bl,blpol
LiquidCrystal_I2C lcd(0x3F, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE);
//--------------------------------------------------------------------------------------


//--------------------------  YF-S201 Sensor  ------------------------------------------
//---------------------------------------------./Global Variables-----------------------
float calibrationFactor = 6.4;
byte sensorInterrupt = 0;
int TurnOffVolume = 0;
volatile byte pulseCount;
float flowRate;
unsigned int flowMilliLitres;
unsigned long totalMilliLitres;
unsigned long oldTime;
//--------------------------------------------------------------------------------------


//-----------------------------  4x4 Keypad   ------------------------------------------
//---------------------------------------------./Global Variables-----------------------
long value = 0;
char keys[4][4] =
{
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};
Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, 4, 4 );
//--------------------------------------------------------------------------------------


//--------------------------  YF-S201 Sensor + Reset Values ----------------------------
//---------------------------------------------./Functions------------------------------
void pulseCounter()
{
  pulseCount++;
}


void Volume() {
  if ((millis() - oldTime) > 1000)   // Only process counters once per second
  {
    detachInterrupt(sensorInterrupt);
    flowRate = ((1000.0 / (millis() - oldTime)) * pulseCount) / calibrationFactor;
    oldTime = millis();
    flowMilliLitres = (flowRate / 60) * 1000;
    totalMilliLitres += flowMilliLitres;
    pulseCount = 0;
    attachInterrupt(sensorInterrupt, pulseCounter, FALLING);
  }
}


void ResetValues() {
  value = 0; //Now reset ready for next input
  totalMilliLitres = 0;
  TurnOffVolume = 10000;
  digitalWrite(valve, HIGH);
}
//--------------------------------------------------------------------------------------



//||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||Setup
void setup() {

  //Serial.begin(38400);

  pinMode(valve, OUTPUT);
  digitalWrite(valve, HIGH);

  //--------------------------  2004A (0x3F) 20x4 LCD Screen ---------------------------
  //-----------------------------------------------./Setup------------------------------
  lcd.begin(20, 4);
  lcd.clear();
  lcd.setCursor(0, 1);
  lcd.print("AUTOMATIC FLOW METER");
  lcd.setCursor(7, 2);
  lcd.print("CONTROL");
  delay(1000);
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Enter Water Amount :");
  lcd.setCursor(0, 2);
  lcd.print("Output Liquid : ");
  lcd.setCursor(0, 3);
  lcd.print(totalMilliLitres);
  lcd.print(" (mL)");
  lcd.setCursor(0, 1);
  lcd.setCursor(0, 1);


  //------------------------------------------------------------------------------------


  //--------------------------  YF-S201 Sensor  ----------------------------------------
  //-----------------------------------------------./Setup------------------------------

  pinMode(sensorPin, INPUT);
  digitalWrite(sensorPin, HIGH);

  pulseCount        = 0;
  flowRate          = 0.0;
  flowMilliLitres   = 0;
  totalMilliLitres  = 0;
  oldTime           = 0;

  attachInterrupt(sensorInterrupt, pulseCounter, FALLING);

  //------------------------------------------------------------------------------------

  delay(1000);
  ResetValues();//To Reset All Variables And Start A New Operation

}
//||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||Setup


//||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||Loop
void loop() {



  //------------------------- Calculate Volume Of Liquid -------------------------------
  Volume();
  //------------------------------------------------------------------------------------


  //----------------------------- Stopping Condition -----------------------------------
  if (totalMilliLitres + (0.03 * totalMilliLitres) >= TurnOffVolume) {
    digitalWrite(valve, HIGH);
    // Print the cumulative total of litres flowed since starting
    lcd.setCursor(0, 2);
    lcd.print("Output Liquid : ");
    lcd.setCursor(0, 3);
    lcd.print(totalMilliLitres);
    lcd.print(" (mL)");
    delay(3000);
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Enter Water Amount :");
    lcd.setCursor(0, 2);
    lcd.print("Output Liquid : ");
    lcd.setCursor(0, 3);
    lcd.print(totalMilliLitres);
    lcd.print(" (mL)");
    lcd.setCursor(0, 1);

    ResetValues();//To Reset All Variables And Start A New Operation
  }
  //------------------------------------------------------------------------------------


  //----------- Saving Keypad Inputs In A Variable For Further Operations --------------
  char key = keypad.getKey();
  //------------------------------------------------------------------------------------

  //------------ Code To Stop Showing "A" , "B" , "C" , "D" When Pressed ---------------
  if (key == 'A' || key == 'B' || key == 'C' || key == 'D') {
    //lcd.print("");
  }

  else
  {
    // lcd.print(key);
  }

  //------------------------------------------------------------------------------------


  delay(1);



  if (key != NO_KEY)
  {


    if ( (key >= '0') && (key <= '9') )
    {
      lcd.print(key);
      value = value * 10;
      value = value + key - '0';
    }
    /////////////////////////////////////////////////////////////////////////////////

    //       A       \\

    /////////////////////////////////////////////////////////////////////////////////

    if ( key == 'A' )
    {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Amount is SET to:");
      lcd.setCursor(0, 1);
      lcd.print("<");
      lcd.print(value);
      lcd.print("> (mL)");
      lcd.setCursor(0, 2);
      lcd.print("Output Liquid : ");
      lcd.setCursor(0, 3);
      lcd.print(totalMilliLitres);
      lcd.print(" (mL)");
      lcd.setCursor(0, 1);
      if (value == 0) {
        ResetValues();//To Reset All Variables And Start A New Operation
      }
      else {
        TurnOffVolume = value;
        digitalWrite(valve, LOW);// Turn ON Pump And Valve (Relay Active LOW)
      }
    }
  }

  /////////////////////////////////////////////////////////////////////////////////

  //       B       \\

  /////////////////////////////////////////////////////////////////////////////////

  if (key == 'B')
  {
    ResetValues();//To Reset All Variables And Start A New Operation
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Enter Water Amount :");
    lcd.setCursor(0, 2);
    lcd.print("Output Liquid : ");
    lcd.setCursor(0, 3);
    lcd.print(totalMilliLitres);
    lcd.print(" (mL)");
    lcd.setCursor(0, 1);
  }

  /////////////////////////////////////////////////////////////////////////////////

  //       C       \\

  /////////////////////////////////////////////////////////////////////////////////

  if (key == 'C')
  {
    ResetValues();//To Reset All Variables And Start A New Operation
    digitalWrite(valve, LOW);// Turn ON Pump And Valve (Relay Active LOW)
    lcd.clear();
    lcd.setCursor(0, 1);
    lcd.print("Water Valve is Open");
    lcd.setCursor(0, 2);
    lcd.print("     Caution !");
  }

  /////////////////////////////////////////////////////////////////////////////////

  //       D       \\

  /////////////////////////////////////////////////////////////////////////////////

  if (key == 'D')
  {
    digitalWrite(valve, HIGH);// Turn Off Pump And Valve (Relay Active LOW)
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Enter Water Amount :");
    lcd.setCursor(0, 2);
    lcd.print("Output Liquid : ");
    lcd.setCursor(0, 3);
    lcd.print(totalMilliLitres);
    lcd.print(" (mL)");
    lcd.setCursor(0, 1);
    ResetValues();//To Reset All Variables And Start A New Operation
  }

  /////////////////////////////////////////////////////////////////////////////////

  //       *       \\

  /////////////////////////////////////////////////////////////////////////////////

  if (key == '*')
  {
    digitalWrite(valve, HIGH);// Turn Off Pump And Valve (Relay Active LOW)

    lcd.clear();

    lcd.setCursor(0, 1);
    lcd.print("AUTOMATIC FLOW METER");
    lcd.setCursor(7, 2);
    lcd.print("CONTROL");
    delay(5000);


    lcd.clear();

    lcd.setCursor(0, 0);
    lcd.print("Enter Water Amount :");
    lcd.setCursor(0, 2);
    lcd.print("Output Liquid : ");
    lcd.setCursor(0, 3);
    lcd.print(totalMilliLitres);
    lcd.print(" (mL)");
    lcd.setCursor(0, 1);
    ResetValues();//To Reset All Variables And Start A New Operation
  }

  /////////////////////////////////////////////////////////////////////////////////

}//end of loop
//||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||Loop