#include <LiquidCrystal.h>


/*******************************************************

This program will test the LCD panel and the buttons
Mark Bramwell, July 2010

********************************************************/

// select the pins used on the LCD panel
const int rs = 7, en = 6, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
///LiquidCrystal lcd(8, 9, 4, 5, 6, 7);

// define some values used by the panel and buttons
int lcd_key     = 0;
int adc_key_in  = 0;

#define btnRIGHT  0
#define btnUP     1
#define btnDOWN   2
#define btnLEFT   3
#define btnSELECT 4
#define btnNONE   5
byte prev_screen;
byte prev_lcd_key;
byte sensorInterrupt = 8;
byte sensorPin       = 9;
byte relayPin        = 10;
float calibrationFactor = 4.5;
float flowRate = 0;
volatile byte pulseCount = 0;
unsigned long flowMilliLitres = 0;
unsigned long totalMilliLitresA = 0;
byte screen = 0;
int set_point = 0;
byte edit = 0;
unsigned long oldTime = 0;
byte key_input;
byte statusLed    = 13;

int total_litres = 0;
byte display_run = 0;



// read the buttons
int read_LCD_buttons()
{
  adc_key_in = analogRead(0);      // read the value from the sensor
  if (adc_key_in > 1000) return btnNONE; // We make this the 1st option for speed reasons since it will be the most likely result
  if (adc_key_in < 50)   return btnRIGHT;
  if (adc_key_in < 195)  return btnUP;
  if (adc_key_in < 380)  return btnDOWN;
  if (adc_key_in < 555)  return btnLEFT;
  if (adc_key_in < 790)  return btnSELECT;



  return btnNONE;  // when all others fail, return this...
}

void setup()
{
  lcd.begin(16, 2);              // start the library
  lcd.clear();
  lcd.setCursor(0, 0);
  Serial.begin (9600);
  attachInterrupt(sensorInterrupt, pulseCounter, FALLING);

}

void loop()
{
  

  pinMode(statusLed, OUTPUT);
  pinMode(relayPin, OUTPUT);
  lcd_key = read_LCD_buttons();  // read the buttons

  if (prev_lcd_key != lcd_key) {

    switch (lcd_key)  // depending on which button was pushed, we perform an action
    {
      case btnRIGHT:
        {
          key_input = 2;
          break;
        }
      case btnLEFT:
        {
          key_input = 1;
          break;
        }
      case btnUP:
        {
          if (edit == 1)
          {
            set_point++;
          }
          break;
        }
      case btnDOWN:
        {
          if (edit == 1)
          {
            set_point--;
          }
          break;
        }
      case btnSELECT:
        {
          if (screen == 1) {
            screen = 0;
            edit = 0;
          }
          else
          { screen = 1;
            edit = 1;
          }
          break;
        }
      case btnNONE:
        {
          key_input=0;
          break;
        }
    }
  }
  prev_lcd_key = lcd_key;

  if (set_point < 0) {
    set_point = 1;
  }
  if (set_point > 135) {
    set_point = 135;
  }



  if (key_input == 1) {
    totalMilliLitresA = 0;
    total_litres = 0;
    display_run = 1;
    digitalWrite(statusLed, HIGH);
    digitalWrite(relayPin, LOW);
 
  }

  if (key_input == 2) {
    display_run = 0;
    digitalWrite(statusLed, LOW);
    digitalWrite(relayPin, HIGH);
  }
  
  if (total_litres >= set_point) {
    display_run = 0;
    digitalWrite(statusLed, LOW);
    digitalWrite(relayPin, HIGH);
  }

  if ((millis() - oldTime) > 1000)   // Only process counters once per second
  {

    detachInterrupt(sensorInterrupt);
    flowRate = ((1000.0 / (millis() - oldTime)) * pulseCount) / calibrationFactor;
    oldTime = millis();
    // convert to millilitres.
    flowMilliLitres = (flowRate / 60) * 1000;

    totalMilliLitresA += flowMilliLitres;

    if (display_run == 1) {
      total_litres = totalMilliLitresA / 1000;
    }
    pulseCount = 0;
    attachInterrupt(sensorInterrupt, pulseCounter, FALLING);
  }
  
  Serial.print ("display: ");
  Serial.print (display_run);
  Serial.print (" ml: ");
  Serial.print (totalMilliLitresA);
  Serial.print (" L ");
  Serial.print (total_litres);
  Serial.print (" setpoint ");
  Serial.println (set_point);
  
  if (prev_screen != screen) {
    lcd.clear();
  }

  lcd.setCursor(0, 0);
  switch (screen) {
    case 0:
      lcd.setCursor(0, 0);
      lcd.print("Flow: ");
      if (flowRate < 10){
        lcd.print(" ");}
      lcd.print(flowRate, 2);
      lcd.setCursor(12, 0);
      lcd.print(total_litres);
      lcd.print("L");
      lcd.setCursor(3, 1);
      lcd.print(set_point);
      lcd.print(" L");
      break;

    case 1:
      lcd.setCursor(0, 0);
      lcd.print(set_point);
      lcd.print(" L");
      lcd.setCursor(0, 1);
      lcd.print("select to set");
      break;
  }
  prev_screen = screen;
}

void pulseCounter()
{
  // Increment the pulse counter
  pulseCount++;
}