Arduino code

#include <SoftwareSerial.h>
//Setting Up port, Wifi Id,Pass, server address etc.
#define RX 2
#define TX 3
String AP = "invalid";       // AP NAME
String PASS = "029144653Ss@$#"; // AP PASSWORD
String API = "WEO2LZHKNHV1ABR9";   // Write API KEY
String HOST = "api.thingspeak.com";
String PORT = "80";
String field = "field2";
int countTrueCommand;
int countTimeCommand;
boolean found = false;
float valSensor = 1;
int measurePin = A0;
int ledPower = 12;

int samplingTime = 280;
int deltaTime = 40;
int sleepTime = 9680;

float voMeasured = 0;
float calcVoltage = 0;
float dustDensity = 0;
SoftwareSerial esp8266(RX, TX);

#Begin the Wifi connectivity 
void setup() {
  Serial.begin(9600);
  pinMode(ledPower, OUTPUT);
  esp8266.begin(115200);
  sendCommand("AT", 5, "OK");
  sendCommand("AT+CWMODE=1", 5, "OK");
  sendCommand("AT+CWJAP=\"" + AP + "\",\"" + PASS + "\"", 20, "OK");
}

# Send the data into the server
void loop() {
  valSensor = getSensorData();
  String getData = "GET /update?api_key=" + API + "&" + field + "=" + String(valSensor);
  sendCommand("AT+CIPMUX=1", 5, "OK");
  sendCommand("AT+CIPSTART=0,\"TCP\",\"" + HOST + "\"," + PORT, 15, "OK");
  sendCommand("AT+CIPSEND=0," + String(getData.length() + 4), 4, ">");
  esp8266.println(getData); delay(1500); countTrueCommand++;
  sendCommand("AT+CIPCLOSE=0", 5, "OK");
  delay(60000);
}


#get the sensor data

float getSensorData() {
  
  digitalWrite(ledPower, LOW); // power on the LED
  delayMicroseconds(samplingTime);

  voMeasured = analogRead(measurePin); // read the dust value

  delayMicroseconds(deltaTime);
  digitalWrite(ledPower, HIGH); // turn the LED off
  delayMicroseconds(sleepTime);

  calcVoltage = voMeasured * (5.0 / 1024);

  dustDensity = 0.17 * calcVoltage - 0.1;
  dustDensity *= 1000;
  Serial.print("Raw Signal Value (0-1023): ");
  Serial.print(voMeasured);

  Serial.print(" - Voltage: ");
  Serial.print(calcVoltage);

  Serial.print(" - Dust Density: ");
  Serial.println(dustDensity);
  return dustDensity;
}



#check whatif the data was send successfully or not
void sendCommand(String command, int maxTime, char readReplay[]) {
  Serial.print(countTrueCommand);
  Serial.print(". at command => ");
  Serial.print(command);
  Serial.print(" ");
  while (countTimeCommand < (maxTime * 1))
  {
    esp8266.println(command);//at+cipsend
    if (esp8266.find(readReplay)) //ok
    {
      found = true;
      break;
    }

    countTimeCommand++;
  }

  if (found == true)
  {
    Serial.println("OYI");
    countTrueCommand++;
    countTimeCommand = 0;
  }

  if (found == false)
  {
    Serial.println("Fail");
    countTrueCommand = 0;
    countTimeCommand = 0;
  }

  found = false;
}