include <ESP8266WiFi.h>
#include <WiFiClient.h>
#include <ESP8266WebServer.h>
#include <DHT.h>
#define DHTTYPE DHT22
#define DHTPIN  2

// vytvoření proměnné s naším API klíčem z Thingspeak - viz návod
String apiKlic = "******";
// vytvoření proměnné s názvem serveru Thingspeaku
const char* server_ths = "api.thingspeak.com";
const char* ssid     = "mojewifi";
const char* password = "******";
WiFiClient client;

ESP8266WebServer server(80);

DHT dht(DHTPIN, DHTTYPE, 22);

float humidity, temp_f;
String webString="";

unsigned long previousMillis = 0;
const long interval = 2000;

void handle_root() {
 
   gettemperature();
   webString="Teplota:"+String(temp_f)+"C | Vlhkost:"+String((int)humidity)+"%";

   server.send(200, "text/plain", webString);

  delay(100);
  
}

void setup(void)
{

  pinMode(LED_BUILTIN, OUTPUT);
 
  Serial.begin(57600);
  dht.begin();

  WiFi.softAPdisconnect(true);
  WiFi.begin(ssid, password);
  
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    if (WiFi.status() == WL_CONNECTED) {digitalWrite(LED_BUILTIN, LOW);digitalWrite(LED_BUILTIN, HIGH);}
    if (WiFi.status() == WL_DISCONNECTED) {digitalWrite(LED_BUILTIN, HIGH);digitalWrite(LED_BUILTIN, LOW);}
  
  }
  server.on("/", handle_root);
  server.begin();
}

void loop(void)
{
 server.handleClient();
//  připojení na server Thingspeak pro odeslání dat
 if (client.connect(server_ths,80)) {
   String zprava = apiKlic;
   zprava +="&field5=";
   zprava += String(temp_f);
   zprava +="&field6=";
   zprava += String(humidity);
   zprava += "\r\n\r\n";
   client.print("POST /update HTTP/1.1\n");
   client.print("Host: api.thingspeak.com\n");
   client.print("Connection: close\n");
   client.print("X-THINGSPEAKAPIKEY: "+apiKlic+"\n");
   client.print("Content-Type: application/x-www-form-urlencoded\n");
   client.print("Content-Length: ");
   client.print(zprava.length());
   client.print("\n\n");
   client.print(zprava);
 }
  client.stop();
  delay(30000);  
}




void gettemperature() {
  unsigned long currentMillis = millis();
  if(currentMillis - previousMillis >= interval) {
    previousMillis = currentMillis;
    humidity = dht.readHumidity();
    temp_f = dht.readTemperature();
    }
  }