/*
I2C-LCD and Web Temperature monitor utilizes Dallas Semiconductor / Maxim DS18B20
One-Wire Digital Temperature sensors to monitor two freezers used as beer storage coolers.
The temperatures are available from a 20x4 LCD and by accessing a small text based web page
generated in response to a "GET" command.


One-Wire data channel is on digital pin 8, which is pulled up to +5v with a 4K7 resistor.

The ethernet interface is the Wiznet W5100 based Ethernet Shield.

If you are using multiple Arduino/Ethernet shields, each one must have a unique MAC address and
IP Address.

*/

// include the library code:
#include <Wire.h>
#include <LCD.h>
#include <LiquidCrystal_I2C.h>
#include <SPI.h>
#include <Ethernet.h>
#include <OneWire.h>

// Debug defines
// #define SerialDebug

// I2C LCD Defines
#define I2C_ADDR    0x27  // Define I2C Address where the PCF8574A is
#define BACKLIGHT_PIN     3
#define En_pin  2
#define Rw_pin  1
#define Rs_pin  0
#define D4_pin  4
#define D5_pin  5
#define D6_pin  6
#define D7_pin  7

int n = 1;

LiquidCrystal_I2C	lcd(I2C_ADDR,En_pin,Rw_pin,Rs_pin,D4_pin,D5_pin,D6_pin,D7_pin);


#define backLightPin 3


const int cols        = 20;
const int rows        = 4;
const int tooCold     = 45;
const int tooHot      = 60;
const byte nbsp       = 0x20; //space character
const byte zeroChar   = 0x30; // zero character
const int maxSensors  = 4;
const int dsDataPin = 8;


// Enter a MAC address and IP address for your controller below.
// The IP address will be dependent on your local network:

byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
IPAddress ip(192,168,1,177);

// Initialize the Ethernet server library
// with the IP address and port you want to use 
// (port 80 is default for HTTP):
EthernetServer server(80);

/********** OneWire Stuff ************/
OneWire  ds(dsDataPin); // OneWire data bus
float fahrenheit[4];
int cnt = 0;
int maxCnt = 0;


void setup()
{
  // set up the LCD's number of columns and rows: 
  lcd.begin(cols, rows);
  lcd.setBacklightPin(BACKLIGHT_PIN,POSITIVE);
  lcd.setBacklight(HIGH);
  lcd.clear();
  lcd.home();

  // Print a message to the LCD.

// Open serial communications and wait for port to open:
  Serial.begin(9600);
 #if defined SerialDebug
  Serial.println(F("Checking for OneWire Devices"));
 #endif

 byte addr[8];
 
  while ( ds.search(addr)) {
    cnt++;
    delay(500);
  }
  
  ds.reset_search();

  maxCnt = cnt;
  cnt=0;

#if defined SerialDebug
  Serial.println(F("No more addresses."));
  Serial.print(F("maxCnt = "));
  Serial.println(maxCnt);
#endif

  // start the Ethernet connection and the server:
  Ethernet.begin(mac, ip);
  server.begin();
#if defined SerialDebug
  Serial.print("server is at ");
  Serial.println(Ethernet.localIP());
#endif
}

void getOneWire(void)
{
  byte i;
  byte present = 0;
  byte type_s;
  byte data[12];
  byte addr[8];
  
#if defined SerialDebug
  Serial.println(F("Checking for OneWire Devices"));
#endif
 
  if (!ds.search(addr))
  {
    maxCnt = cnt;
    cnt=0;
    ds.reset_search();
    delay(500);
#if defined SerialDebug
    Serial.println(F("No more addresses."));
#endif
   return;
  }

#if defined SerialDebug
  Serial.print(F("ROM "));
  Serial.print(cnt);
  Serial.print(F(" = "));
  for( i = 0; i < 8; i++)
  {
    Serial.write(nbsp);
    if(addr[i] < 16){Serial.write(zeroChar);} // prepend hex 0-15 with a 0
    Serial.print(addr[i], HEX);
  }

  if (OneWire::crc8(addr, 7) != addr[7]) {
      Serial.println(F("CRC is not valid!"));
      return;
  }
  Serial.println();
#endif

  // the first ROM byte indicates which chip
  switch (addr[0]) {
    case 0x10:
#if defined SerialDebug
      Serial.println(F("Chip = DS18S20"));  // or old DS1820
#endif
      type_s = 1;
      break;
    case 0x28:
#if defined SerialDebug
      Serial.println(F("Chip = DS18B20"));
#endif
      type_s = 0;
      break;
    case 0x22:
#if defined SerialDebug
      Serial.println(F("Chip = DS1822"));
#endif
      type_s = 0;
      break;
    default:
      Serial.println(F("Not a DS18x20"));
      return;
  } 

  ds.reset();
  ds.select(addr);
  ds.write(0x44,1);         // start conversion, with parasite power on at the end
  
  delay(750);     // 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

#if defined SerialDebug
  Serial.print(F("  Data = "));
  if(present < 16){Serial.write(zeroChar);} // prepend hex 0-15 with a 0
  Serial.print(present, HEX);
  Serial.write(nbsp);
#endif
  for ( i = 0; i < 9; i++) {           // we need 9 bytes
    data[i] = ds.read();
#if defined SerialDebug
    if(data[i] < 16){Serial.write(zeroChar);} // prepend hex 0-15 with a 0
    Serial.print(data[i], HEX);
    Serial.write(nbsp);
#endif
  }
#if defined SerialDebug
  Serial.print(F(" CRC="));
  Serial.print(OneWire::crc8(data, 8), HEX);
  Serial.println();
#endif
  // convert the data to actual temperature

  unsigned int raw = (data[1] << 8) | data[0];
  if (type_s) {
    raw = raw << 3; // 9 bit resolution default
    if (data[7] == 0x10) {
      // count remain gives full 12 bit resolution
      raw = (raw & 0xFFF0) + 12 - data[6];
    }
  } else {
    unsigned char t_mask[4] = {0x7, 0x3, 0x1, 0x0};
    byte cfg = (data[4] & 0x60) >> 5;
    raw &= ~t_mask[cfg];
  }
  fahrenheit[cnt] = ((((float)raw / 16.0) * 1.8) + 31.0); //the raw value is Celsius, convert to Fahrenheit
#if defined SerialDebug
  Serial.print("  Temperature = ");
  Serial.print(fahrenheit[cnt]);
  Serial.println(" Fahrenheit");
#endif
  cnt++;
}

void checkEthernet(void)
{
 // listen for incoming clients
  EthernetClient client = server.available();
  if (client) {
    Serial.println("new client");
    // an http request ends with a blank line
    boolean currentLineIsBlank = true;
    while (client.connected()) {
      if (client.available()) {
        char c = client.read();
        Serial.write(c);
        // if you've gotten to the end of the line (received a newline
        // character) and the line is blank, the http request has ended,
        // so you can send a reply
        if (c == '\n' && currentLineIsBlank) {
          // send a standard http response header
          client.println(F("HTTP/1.1 200 OK"));
          client.println(F("Content-Type: text/html"));
          client.println(F("Connnection: close"));
          client.println();
          client.println(F("<!DOCTYPE HTML>"));
          client.println("<html><head>");
                    // add a meta refresh tag, so the browser pulls again every 5 seconds:
          client.println(F("<meta http-equiv=\"refresh\" content=\"5\">"));
          client.println(F("</head>"));
          // output the value of each analog input pin
          client.println(F("<body><table border=\"5\" align=\"center\"><tr>"));
          switch(maxCnt)
          {
            case 0:
             client.println(F("<td align=\"center\" valign=\"center\"><font size=\"10\" color=\"red\">SENSOR FAILURE<br />OR<br />POWER FAILURE!!</td>"));
             break;
             
            case 1:
            case 2:
            case 3:
            case 4:
              for (int n=1; n<=maxSensors; n++)
              {
                if(n<=maxCnt)
                {
                  client.print(F("<td align=\"center\" valign=\"center\"><font size=\"10\">&nbsp;&nbsp;Freezer "));
                  client.print(n);
                  client.print(F("&nbsp;&nbsp;<br />"));
                  if((int)fahrenheit[n-1] > tooHot)
                    {
                      client.print(F("<font color=\"red\">"));
                    }else if((int)fahrenheit[n-1] < tooCold){
                      client.print(F("<font color=\"blue\">"));
                    }else{
                      client.print(F("<font color=\"green\">"));
                    }
                  client.print(fahrenheit[n-1], 0);
                  client.println(F("&deg;F</font></font></td>"));
                }else{
                  client.println(F("<td align=\"center\" valign=\"center\"><font size=\"10\" color=\"red\">SENSOR<br />FAILURE</font></td>"));
                }
              }
              break;

            default:
              client.println(F("<td align=\"center\" valign=\"center\"><font size=\"10\" color=\"red\">SOMETHING IS NOT RIGHT!<br /> TOO MANY SENSORS!!</td>"));
              break;
          }
          client.println(F("</tr></table></body>"));
          client.println(F("</html>"));
          break;
        }
        if (c == '\n') {
          // you're starting a new line
          currentLineIsBlank = true;
        } 
        else if (c != '\r') {
          // you've gotten a character on the current line
          currentLineIsBlank = false;
        }
      }
    }
    // give the web browser time to receive the data
    delay(1);
    // close the connection:
    client.stop();
#if defined SerialDebug
    Serial.println(F("client disonnected"));
#endif
  }
}

void displayLCDTemp()
{
  lcd.home();

  switch(maxCnt)
  {
    case 0:
      lcd.print(F("Sensor Failure!!"));
      lcd.setCursor(0, 1);
      lcd.print(F("Sensor Failure!!"));
      lcd.setCursor(0, 2);
      lcd.print(F("Sensor Failure!!"));
      lcd.setCursor(0, 3);
      lcd.print(F("Sensor Failure!!"));
      break;

    case 1:
    case 2:
    case 3:
    case 4:
      for(int n=1;n<=maxSensors;n++)
      {
        if(n<=maxCnt)
        {
          lcd.setCursor(0, n-1);
          lcd.print(F("Freezer "));
          lcd.print(n);
          lcd.print(F(" = "));
          lcd.print(fahrenheit[n-1],0);
          lcd.print(F("     "));
        }else{
          lcd.setCursor(0,n-1);
          lcd.print(F("Sensor Failure!!"));
        }
      }
     break;

    default:
      lcd.print(F("    SOMETHING IS    "));
      lcd.setCursor(0, 1);
      lcd.print(F("     NOT RIGHT!     "));
      lcd.setCursor(0, 2);
      lcd.print(F("      TOO MANY      "));
      lcd.setCursor(0, 3);
      lcd.print(F("      SENSORS!      "));
    }

}

void loop()
{
  getOneWire();
  checkEthernet();
  displayLCDTemp();
  delay(250);
}