#include <LiquidCrystal.h>
#include <OneWire.h>

// LCD=======================================================
//initialize the library with the numbers of the interface pins
 LiquidCrystal lcd(12, 11, 5, 4, 3, 2); // Defines LCD pins
#define LCD_WIDTH 20
#define LCD_HEIGHT 2

const int compStart = 9;    // Defines Compressor pin
const int fanStart = 8;    // Defines fan-pin

const int lowThresh = 2640;   //sets temp when compressor stops
const int highThresh = 2650;  //sets temp when compressor starts

const int lowFan = 2600;      //sets temp when fan starts
const int highFan = 2630;      //sets temp when fan stops


// DS18S20 Temperature chip i/o
OneWire ds(10);  // on pin 10

void setup(void) {
  // initialize inputs/outputs
  // start serial port
  Serial.begin(9600);

  //Setup LCD 16x2 and display startup message
  lcd.begin(16, 2);
  lcd.print("  Smart Fridge");
  lcd.setCursor(0,1);
  lcd.print("  Starting Up");
  delay(1000);
  lcd.clear();

}

void loop(void) {

  int HighByte, LowByte, TReading, SignBit, Tc_100, Whole, Fract;

  byte i;
  byte present = 0;
  byte data[12];
  byte addr[8];
  char* current_ds_addr = "";

  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(4000);     // 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(" ");
  }
  Serial.print(" CRC=");
  Serial.print( OneWire::crc8( data, 8), HEX);
  Serial.println();

  LowByte = data[0];
  HighByte = data[1];
  TReading = (HighByte << 8) + LowByte;
  SignBit = TReading & 0x8000;  // test most sig bit
  if (SignBit) // negative
  {
    TReading = (TReading ^ 0xffff) + 1; // 2's comp
  }
  Tc_100 = (6 * TReading) + TReading / 4;    // multiply by (100 * 0.0625) or 6.25

  Whole = Tc_100 / 100;  // separate off the whole and fractional portions
  Fract = Tc_100 % 100;


  if (SignBit) // If its negative
  {
     Serial.print("-");
  }
  Serial.print(Whole);
  Serial.print(".");
  if (Fract < 10)
  {
     Serial.print("0");
  }
  Serial.print(Fract);

  Serial.print("\n");

  //print onto LCD
    lcd.setCursor(0,0);
    lcd.print("Tmp:");
    lcd.print(Whole);
    lcd.print(".");
    lcd.print(Fract);
    lcd.setCursor(0,1);
    lcd.print("Fan:");

  lcd.setCursor(10,0);
  for( i = 0; i < 8; i++) {
    lcd.print(addr[i], HEX);

  if (Tc_100 > highThresh) {
  digitalWrite(compStart,HIGH);
  }
  else if (Tc_100 < lowThresh)
  digitalWrite(compStart,LOW);
  }
  if (Tc_100 < lowFan) {
  digitalWrite(fanStart,HIGH);
  }
  else if (Tc_100 > highFan) {
  digitalWrite(fanStart,LOW);
}
}