#include <SoftwareSerial.h> //Software Serial library
SoftwareSerial espSerial(2, 3);//Pin 2 and 3 act as RX and TX.
#define DEBUG true
String mySSID = "xxxx";       // WiFi SSID
String myPWD = "yyyyyy"; // WiFi Password
String myAPI = "xyxyxyyxxyyxxxyy";   // API Key
String myHOST = "api.thingspeak.com";
String myPORT = "80";
String myFIELD = "field1";
int sendVal;


void setup()
{
  Serial.begin(9600);
  espSerial.begin(115200);
  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);

  delay(1000);

}
void loop(){
sendVal = random(1000); // Send a random number between 1 and 1000
String sendData = "GET /update?api_key="+ myAPI +"&"+myFIELD+"="+String(sendVal);
    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(sendVal);

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

  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;
}