/* Arduino+esp8266 thingSpeak example
 * Example name = "Write temperature and humidity to Thingspeak channel"
 * Created by Ilias Lamprou
 * Updated Oct 30 2016
 *
 * Download latest Virtuino android app from the link:https://play.google.com/store/apps/details?id=com.virtuino_automations.virtuino&hl
 * Video tutorial link: https://youtu.be/4XEe0HY0j6k
 * Contact address for questions or comments: iliaslampr@gmail.com
 */

// Code to use SoftwareSerial
#include <SoftwareSerial.h>
SoftwareSerial espSerial =  SoftwareSerial(2,3);      // arduino RX pin=2  arduino TX pin=3    connect the arduino RX pin to esp8266 module TX pin   -  connect the arduino TX pin to esp8266 module RX pin

#define anInput     A0                        //analog feed from MQ135
#define co2Zero     55                        //calibrated CO2 0 level

String apiKey = "WR24HU4MCYDRHBQH";     // replace with your channel's thingspeak WRITE API key

String ssid="Honor";    // Wifi network SSID
String password ="qwertyuiop";  // Wifi network password

boolean DEBUG=true;

//======================================================================== showResponce
void showResponse(int waitTime){
    long t=millis();
    char c;
    while (t+waitTime>millis()){
      if (espSerial.available()){
        c=espSerial.read();
        if (DEBUG) Serial.print(c);
      }
    }

}

//========================================================================
boolean thingSpeakWrite(float value1){
  String cmd = "AT+CIPSTART=\"TCP\",\"";                  // TCP connection
  cmd += "184.106.153.149";                               // api.thingspeak.com
  cmd += "\",80";
  espSerial.println(cmd);
  if (DEBUG) Serial.println(cmd);
  if(espSerial.find("Error")){
    if (DEBUG) Serial.println("AT+CIPSTART error");
    return false;
  }


  String getStr = "GET /update?api_key=";   // prepare GET string
  getStr += apiKey;

  getStr +="&field1=";
  getStr += String(value1);
  //getStr +="&field2=";
  //getStr += String(value2);
  //getStr +="&field3=";
  //getStr += String(value3);
  //getStr +="&field4=";
  //getStr += String(value4);
  // ...
  getStr += "\r\n";

  // send data length
  cmd = "AT+CIPSEND=";
  cmd += String(getStr.length());
  espSerial.println(cmd);
  if (DEBUG)  Serial.println(cmd);

  delay(100);
  if(espSerial.find(">")){
    espSerial.print(getStr);
    if (DEBUG)  Serial.print(getStr);
  }
  else{
    espSerial.println("AT+CIPCLOSE");
    // alert user
    if (DEBUG)   Serial.println("AT+CIPCLOSE");
    return false;
  }
  return true;
}
//================================================================================ setup
void setup() {
  DEBUG=true;           // enable debug serial
  Serial.begin(9600);

  pinMode(anInput,INPUT);                     //MQ135 analog feed set for input


  espSerial.begin(9600);  // enable software serial
                          // Your esp8266 module's speed is probably at 115200.
                          // For this reason the first time set the speed to 115200 or to your esp8266 configured speed
                          // and upload. Then change to 9600 and upload again

  //espSerial.println("AT+RST");         // Enable this line to reset the module;
  //showResponse(1000);

  //espSerial.println("AT+UART_CUR=9600,8,1,0,0");    // Enable this line to set esp8266 serial speed to 9600 bps
  //showResponse(1000);



  espSerial.println("AT+CWMODE=1");   // set esp8266 as client
  showResponse(1000);

  espSerial.println("AT+CWJAP=\""+ssid+"\",\""+password+"\"");  // set your home router SSID and password
  showResponse(5000);

   if (DEBUG)  Serial.println("Setup completed");


}


// ====================================================================== loop
void loop() {
//+++++++++++++++++++++++++++MQ135+++++++++++++++++++++++
int co2now[10];                               //int array for co2 readings
int co2raw = 0;                               //int for raw value of co2
int co2comp = 0;                              //int for compensated co2
int co2ppm = 0;                               //int for calculated ppm
int zzz = 0;                                  //int for averaging
int grafX = 0;                                //int for x value of graph


  for (int x = 0;x<10;x++){                   //samplpe co2 10x over 2 seconds
    co2now[x]=analogRead(A0);
    delay(200);
  }

for (int x = 0;x<10;x++){                     //add samples together
    zzz=zzz + co2now[x];

  }
  co2raw = zzz/10;                            //divide samples by 10
  co2comp = co2raw - co2Zero;                 //get compensated value
  co2ppm = map(co2comp,0,1023,400,5000);      //map value for atmospheric levels
 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

thingSpeakWrite(co2ppm);
//============================================================
  // thingspeak needs 15 sec delay between updates,
  delay(20000);
}