#include <SoftwareSerial.h>       //Software Serial library
#include "DHT.h"                  // připojení knihovny DHT
#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

SoftwareSerial espSerial(10, 11);   //Pin 2 and 3 act as RX and TX. Connect them to TX and RX of ESP8266      
#define DEBUG true
#define pinDHT 5
#define typDHT11 DHT11     // DHT 11

#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels

// Declaration for SSD1306 display connected using software SPI (default case):
#define OLED_MOSI   9
#define OLED_CLK   10
#define OLED_DC    11
#define OLED_CS    12
#define OLED_RESET 13
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT,
  OLED_MOSI, OLED_CLK, OLED_DC, OLED_RESET, OLED_CS);
  
String mySSID = "******";       // WiFi SSID
String myPWD = "*******"; // WiFi Password
String myAPI = "*********";   // API Key
String myHOST = "api.thingspeak.com";
String myPORT = "80";
String tepFIELD = "field1"; 
String humField = "field2";
int teplota;
int vlhkost;

DHT mojeDHT(pinDHT, typDHT11);

void setup()
{
  Serial.begin(9600);

  // SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
  if(!display.begin(SSD1306_SWITCHCAPVCC)) {
    Serial.println(F("SSD1306 allocation failed"));
    for(;;); // Don't proceed, loop forever
  }
  mojeDHT.begin();
  espSerial.begin(115200);

  vypsani_hodnot_na_display();    // Draw 'stylized' characters
  
  espData("AT+RST", 1000, DEBUG);                      //Reset the ESP8266 module
  espData("AT+CWMODE=1", 1000, DEBUG);                 //Set the ESP mode as station mode
  espData("AT+CWJAP=\""+ mySSID +"\",\""+ myPWD +"\"", 1000, DEBUG);   //Connect to WiFi network
  /*while(!esp.find("OK")) 
  {          
      //Wait for connection
  }*/
  delay(1000);
  
}

  void loop()
  {
    /* Here, I'm using the function random(range) to send a random value to the 
     ThingSpeak API. You can change this value to any sensor data
     so that the API will show the sensor data  
    */
      // cidloDHT11
      float tep = mojeDHT.readTemperature();
      float vlh = mojeDHT.readHumidity();
      // kontrola, jestli jsou načtené hodnoty čísla pomocí funkce isnan
     if (isnan(tep) || isnan(vlh)) {
      // při chybném čtení vypiš hlášku
      Serial.println("Chyba při čtení z DHT senzoru!");
      } else {
      // pokud jsou hodnoty v pořádku, 
      // vypiš je po sériové lince
      Serial.print("Teplota: "); 
      Serial.print(tep);
      Serial.print(" stupnu Celsia, ");
      Serial.print("vlhkost: "); 
      Serial.print(vlh);
       Serial.println("  %");
      }
      // pauza pro přehlednější výpis
      delay(2000);
    // cidlo DHT11
    teplota = (tep); // Send a random number between 1 and 1000
    vlhkost = (vlh);
    String sendData = "GET /update?api_key="+ myAPI +"&"+ tepFIELD +"="+String(teplota) +","+ "&field2" +"=" +String(vlhkost);
    // String sendData = "GET /update?api_key="+ myAPI + "&field1" +"="+String(t) +","+ "&field2" +"=" +String(h);
    Serial.print(sendData);
    espData("AT+CIPMUX=1", 1000, DEBUG);       //Allow multiple connections
    espData("AT+CIPSTART=0,\"TCP\",\""+ myHOST +"\","+ myPORT, 1000, DEBUG);
    espData("AT+CIPSEND=0," +String(sendData.length()+4),1000,DEBUG);  
    espSerial.find(">"); 
    espSerial.println(sendData);
    Serial.print("Value to be sent: ");
    Serial.println(teplota);
    Serial.println(vlhkost);

     
    espData("AT+CIPCLOSE=0",1000,DEBUG);
    delay(10000);
  }

  void vypsani_hodnot_na_display(void) {
  display.clearDisplay();

  display.setTextSize(3);             // Normal 1:1 pixel scale
  display.setTextColor(SSD1306_WHITE);        // Draw white text
  display.setCursor(0,0);             // Start at top-left corner
  display.println(F("We Can Do it!"));

  display.setTextSize(1);             // Draw 2X-scale text
  display.setTextColor(SSD1306_BLACK, SSD1306_WHITE); // Draw 'inverse' text
  display.println(3.141592);

  display.setTextSize(1);             // Draw 2X-scale text
  display.setTextColor(SSD1306_WHITE);
  display.print(F("0x")); display.println(0xDEADBEEF, HEX);

  display.display();
  delay(2000);
}


  String espData(String command, const int timeout, boolean debug)
{
  Serial.print("AT Command ==> ");
  Serial.print(command);
  Serial.println("     ");
  
  String response = "";
  espSerial.println(command);
  long int time = millis();
  while ( (time + timeout) > millis())
  {
    while (espSerial.available())
    {
      char c = espSerial.read();
      response += c;
    }
  }
  if (debug)
  {
    //Serial.print(response);
  }
  return response;
}