/*

 Arduino --> ThingSpeak Channel via Ethernet

 The ThingSpeak Client sketch is designed for the Arduino and Ethernet.
 This sketch updates a channel feed with an analog input reading via the
 ThingSpeak API (http://community.thingspeak.com/documentation/)
 using HTTP POST. The Arduino uses DHCP and DNS for a simpler network setup.
 The sketch also includes a Watchdog / Reset function to make sure the
 Arduino stays connected and/or regains connectivity after a network outage.
 Use the Serial Monitor on the Arduino IDE to see verbose network feedback
 and ThingSpeak connectivity status.

 Getting Started with ThingSpeak:

   * Sign Up for New User Account - https://www.thingspeak.com/users/new
   * Register your Arduino by selecting Devices, Add New Device
   * Once the Arduino is registered, click Generate Unique MAC Address
   * Enter the new MAC Address in this sketch under "Local Network Settings"
   * Create a new Channel by selecting Channels and then Create New Channel
   * Enter the Write API Key in this sketch under "ThingSpeak Settings"

 Arduino Requirements:

   * Arduino with Ethernet Shield or Arduino Ethernet
   * Arduino 1.0 IDE

  Network Requirements:

   * Ethernet port on Router
   * DHCP enabled on Router
   * Unique MAC Address for Arduino

 Created: October 17, 2011 by Hans Scharler (http://www.iamshadowlord.com)

 Additional Credits:
 Example sketches from Arduino team, Ethernet by Adrian McEwen

updated by Rick Klink to read DS18B20 temperatures and upload to thingspeak
updated by Ondrej Gottwald to read 4 DS18B20 temperatures and upload to thingspeak


*/
#include <OneWire.h>
#include <DallasTemperature.h>
#include <SPI.h>
#include <Ethernet.h>

// Local Network Settings
byte mac[] = { 0xD4, 0x28, 0xB2, 0xFF, 0xD5, 0x63 }; // Must be unique on local network

// ThingSpeak Settings
char thingSpeakAddress[] = "api.thingspeak.com";
//**********************************************
// Tady zadejte writeAPIkey získaný z ThingSpeak
//**********************************************
String writeAPIKey = "XXXXXXXXXXXXXXXX";

const int updateThingSpeakInterval = 30 * 1000;      // Time interval in milliseconds to update ThingSpeak (number of seconds * 1000 = interval)

// Variable Setup
long lastConnectionTime = 0;
boolean lastConnected = false;
int failedCounter = 0;

// Initialize Arduino Ethernet Client
EthernetClient client;

// Data wire is plugged into pin 3 on the Arduino
#define ONE_WIRE_BUS 3
#define TempRes 10  // set the resolution to 10 bit (resolution for ds18b20 9, 10, 11, 12)

// Setup a oneWire instance to communicate with any OneWire devices
OneWire oneWire(ONE_WIRE_BUS);
// Pass our oneWire reference to Dallas Temperature.
DallasTemperature sensors(&oneWire);
// Assign the addresses of 1-Wire temp sensors.
                                                                                 // Tady zadejte vlastni adresy cidel DS18B20
DeviceAddress RedTemp = { 0x28, 0xD2, 0xCA, 0xF3, 0x00, 0x00, 0x00, 0xD2 };      // ruda,   adresa: 0x28, 0xD2, 0xCA, 0xF3, 0x00, 0x00, 0x00, 0xD2
DeviceAddress YellowTemp = {  0x28, 0x7E, 0x22, 0xF9, 0x03, 0x00, 0x00, 0xE8 };  // zluta,  adresa: 0x28, 0x7E, 0x22, 0xF9, 0x03, 0x00, 0x00, 0xE8
DeviceAddress BlueTemp = {  0x28, 0x37, 0xBF, 0x50, 0x03, 0x00, 0x00, 0x6A };    // modra,  adresa: 0x28, 0x37, 0xBF, 0x50, 0x03, 0x00, 0x00, 0x6A
DeviceAddress GreenTemp = {  0x28, 0xBC, 0x28, 0xF9, 0x03, 0x00, 0x00, 0xA4 };   // zelena, adresa: 0x28, 0xBC, 0x28, 0xF9, 0x03, 0x00, 0x00, 0xA4



void setup()
{
  // Start Serial for debugging on the Serial Monitor
  Serial.begin(9600);

  // Start Ethernet on Arduino
  startEthernet();
  sensors.begin();
  // set the resolution to TempRes value
  sensors.setResolution(RedTemp, TempRes);
  sensors.setResolution(YellowTemp, TempRes);
  sensors.setResolution(BlueTemp, TempRes);
  sensors.setResolution(GreenTemp, TempRes);
}

void loop(void)
{
  // Read value from Analog Input Pin 0
  //String analogPin0 = String(analogRead(A0), DEC);

  // Print Update Response to Serial Monitor
  if (client.available())
  {
    char c = client.read();
    Serial.print(c);
  }

  // Disconnect from ThingSpeak
  if (!client.connected() && lastConnected)
  {
    Serial.println("...disconnected");
    Serial.println();

    client.stop();
  }

  //******************
  //Print Temperatures
  //******************
  Serial.print("Getting temperatures...\n\r");
  sensors.requestTemperatures();
  float RT = sensors.getTempC(RedTemp);  //float = xx,xx ; int = xx
  Serial.print("Red Temp is: ");
  Serial.print(RT);
  Serial.print("C: ");
  Serial.print("\n\r");
  float YT = sensors.getTempC(YellowTemp); //float = xx,xx ; int = xx
  Serial.print("Yellow Temp is: ");
  Serial.print(YT);
  Serial.print("C: ");
  Serial.print("\n\r");
  float BT = sensors.getTempC(BlueTemp); //float = xx,xx ; int = xx
  Serial.print("Blue Temp is: ");
  Serial.print(BT);
  Serial.print("C: ");
  Serial.print("\n\r");
  float GT = sensors.getTempC(GreenTemp);  //float = xx,xx ; int = xx
  Serial.print("Green Temp is: ");
  Serial.print(GT);
  Serial.print("C: ");
  Serial.print("\n\r");

  // Update ThingSpeak
  if(!client.connected() && (millis() - lastConnectionTime > updateThingSpeakInterval))
  {
  updateThingSpeak("field1="+String(RT, DEC)+"&field2="+String(YT, DEC)+"&field3="+String(BT, DEC)+"&field4="+String(GT, DEC));
  }

  // Check if Arduino Ethernet needs to be restarted
  if (failedCounter > 3 ) {startEthernet();}

  lastConnected = client.connected();
}

void updateThingSpeak(String tsData)
{
  if (client.connect(thingSpeakAddress, 80))
  {
    client.print("POST /update HTTP/1.1\n");
    client.print("Host: api.thingspeak.com\n");
    client.print("Connection: close\n");
    client.print("X-THINGSPEAKAPIKEY: "+writeAPIKey+"\n");
    client.print("Content-Type: application/x-www-form-urlencoded\n");
    client.print("Content-Length: ");
    client.print(tsData.length());
    client.print("\n\n");

    client.print(tsData);

    lastConnectionTime = millis();

    if (client.connected())
    {
      Serial.println("Connecting to ThingSpeak...");
      Serial.println();

      failedCounter = 0;
    }
    else
    {
      failedCounter++;

      Serial.println("Connection to ThingSpeak failed ("+String(failedCounter, DEC)+")");
      Serial.println();
    }

  }
  else
  {
    failedCounter++;

    Serial.println("Connection to ThingSpeak Failed ("+String(failedCounter, DEC)+")");
    Serial.println();

    lastConnectionTime = millis();
  }
}

void startEthernet()
{

  client.stop();

  Serial.println("Connecting Arduino to network...");
  Serial.println();

  delay(1000);

  // Connect to network amd obtain an IP address using DHCP
  if (Ethernet.begin(mac) == 0)
  {
    Serial.println("DHCP Failed, reset Arduino to try again");
    Serial.println();
  }
  else
  {
    Serial.println("Arduino connected to network using DHCP");
    Serial.println();
  }

  delay(1000);
}