Monitor Who's Checking In or Checking Out on Your Desktop

#include <SoftwareSerial.h>
SoftwareSerial mySerial(12, 13); // RX, TX

#include <ESP8266WiFi.h>          //https://github.com/esp8266/Arduino
#include <DNSServer.h>
#include <ESP8266WebServer.h>
#include "WiFiManager.h"          //https://github.com/tzapu/WiFiManager
#include <WiFiClientSecure.h>

int count=0,i,m,j,k;

#define SS_PIN 4  //D2
#define RST_PIN 5 //D1

#include <SPI.h>
#include <MFRC522.h>

MFRC522 mfrc522(SS_PIN, RST_PIN);   // Create MFRC522 instance.
int statuss = 0;
int out = 0;
String name1,name2;

//////////////////////////////////////// ALL DECLARATIONS for CLOUD //////////////////////////////
const char* host = "api.thingsai.io";                                 // OR host = devapi2.thethingscloud.com
const char* post_url = "/devices/deviceData";       // OR /api/v2/thingscloud2/_table/data_ac
const char* time_server = "baas.thethingscloud.com";             //this is to convert timestamp
const int httpPort = 80;
const int httpsPort = 443;
const char*  server = "api.thingsai.io";  // Server URL

char timestamp[10];

WiFiClient client;


/////////////////////////////////////////////////////////////////////////////////////////////////////////
void configModeCallback (WiFiManager *myWiFiManager) 
{
  Serial.println("Entered config mode");             //*-*-*-*-*-*-*-*-*-*-*-*-*-*if control enters this function then net is not connected
  Serial.println(WiFi.softAPIP());                  // "WiFi.softAPIP() is for AP" , "WiFi.localIP() is for STA",
                                                                
  Serial.println(myWiFiManager->getConfigPortalSSID());             //if you used auto generated SSID, print it
}
/////////////////////////////////////// TIMESTAMP CALCULATION function///////////////////////////////////////
int GiveMeTimestamp()
{
  unsigned long timeout = millis();

  while (client.available() == 0)
  {
    if (millis() - timeout > 50000)
    {
      client.stop();
      return 0;
    }
  }

while (client.available())
      {
        String line = client.readStringUntil('\r');                    //indexOf() is a funtion to search for smthng , it returns -1 if not found
        int pos = line.indexOf("\"timestamp\"");                       //search for "\"timestamp\"" from beginning of response got and copy all data after that , it'll be your timestamp
        if (pos >= 0)                                                     
        {
          int j = 0;
          for(j=0;j<10;j++)
          {
            timestamp[j] = line[pos + 12 + j];
          }
        }
      }
}  
////////////////////////////////////////////////////////////////////////////////////////////////////////

void setup() 
{
  Serial.begin(115200);     //(19200,SERIAL_8E1) - data size = 8 bits , parity = Even , stop bit =  1bit
  mySerial.begin(115200);
  WiFiManager wifiManager;

  SPI.begin();      // Initiate  SPI bus
  mfrc522.PCD_Init();   // Initiate MFRC522
 
  wifiManager.setAPCallback(configModeCallback);
                                                                                                    
  if(!wifiManager.autoConnect("123456789","dhrumil16999"))                   //wifiManager.autoConnect("AP-NAME", "AP-PASSWORD"); (OR) wifiManager.autoConnect("AP-NAME"); only ID no password (OR) wifiManager.autoConnect(); this will generate a ID by itself
  {
    Serial.println("failed to connect and hit timeout");     //control comes here after long time of creating Access point "NodeMCU" by NodeMCU and still it has not connected
    //reset and try again, or maybe put it to deep sleep
    ESP.reset();
    delay(1000);
  } 

  //if you come here you have connected to the WiFi
  Serial.println("connected...");
 
}

void loop() 
{

 
  
/////////////////////////////////////// SEND THE QUERY AND RECEIVE THE RESPONSE///////////////////////  

  // Look for new cards
  if ( ! mfrc522.PICC_IsNewCardPresent()) 
  {
    return;
  }
  // Select one of the cards
  if ( ! mfrc522.PICC_ReadCardSerial()) 
  {
    return;
  }
  //Show UID on serial monitor
  Serial.println();
  Serial.print(" UID tag :");
  String content= "";
  byte letter;
  for (byte i = 0; i < mfrc522.uid.size; i++) 
  {
     Serial.print(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " ");
     Serial.print(mfrc522.uid.uidByte[i], HEX);
     content.concat(String(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " "));
     content.concat(String(mfrc522.uid.uidByte[i], HEX));
  }
  content.toUpperCase();
  Serial.println();
  if (content.substring(1) == "A0 60 65 A3") //change UID of the card that you want to give access
  {
    Serial.println(" Access Granted ");
    Serial.println(" See you soon xx. xxxxx. ");
    delay(1000);
    Serial.println(" Have FUN ");
    Serial.println();
    statuss = 1;
    name1 = "xx. xxxxx.";
    name2 = '"' + name1 + '"';
  }
  else if (content.substring(1) == "E8 30 75 B3") //change UID of the card that you want to give access
  {
    Serial.println(" Access Granted ");
    Serial.println(" See you soon yy. yyyyy.");
    delay(1000);
    Serial.println(" Have FUN ");
    Serial.println();
    statuss = 1;
    name1 = "yy. yyyyy.";
    name2 = '"' + name1 + '"';
  }
  else   {
    name1 = "Access Denied";
    name2 = '"' + name1 + '"';
    Serial.println("Access Denied");
    delay(3000);
  }

       

       
  Serial.print("connecting to ");
  Serial.println(host);                          //defined upside :- host = devapi2.thethingscloud.com or 139.59.26.117

///////////////////////////////////// TIMESTAMP CODE SNIPPET /////////////////////////
Serial.println("inside get timestamp\n");
  if (!client.connect(time_server, httpPort)) 
  {
    return;                                                        //*-*-*-*-*-*-*-*-*-*
  }

  client.println("GET /api/timestamp HTTP/1.1");                            //Whats this part doing, i didnt get
  client.println("Host: baas.thethingscloud.com");
  client.println("Cache-Control: no-cache");
  client.println("Postman-Token: ea3c18c6-09ba-d049-ccf3-369a22a284b8");
  client.println();

GiveMeTimestamp();                        //it'll call the function which will get the timestamp response from the server
Serial.println("timestamp receieved");
Serial.println(timestamp);
///////////////////////////////////////////////////////////////////////////////

  Serial.println("inside ThingsCloudPost");

 
  String PostValue = "{\"device_id\":  61121695941, \"slave_id\": 1";
         PostValue = PostValue + ",\"dts\":" +timestamp;
   PostValue = PostValue +",\"data\":{\"Check Out\":" + name2 +"}"+"}";
  
  
  Serial.println(PostValue);

/* create an instance of WiFiClientSecure */
    WiFiClientSecure client;
    
    Serial.println("Connect to server via port 443");
    if (!client.connect(server, 443)){
        Serial.println("Connection failed!");
    } else {
        Serial.println("Connected to server!");
        /* create HTTP request */

        client.println("POST /devices/deviceData HTTP/1.1");
        client.println("Host: api.thingsai.io");
        //client.println("Connection: close");
        client.println("Content-Type: application/json");
        client.println("cache-control: no-cache");
        client.println("Authorization: Bearer eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.IjVhMzBkZDFkN2QwYjNhNGQzODkwYzQ4OSI.kaY6OMj5cYlWNqC2PNTkXs9PKy6_m9tdW5AG7ajfVlY");
        client.print("Content-Length: ");
        client.println(PostValue.length());
        client.println();
        client.println(PostValue);
//////////////////////////////////POSTING the data on to the cloud is done and now get the response form cloud server//////////////////
 Serial.print("Waiting for response ");
        while (!client.available()){
            delay(50); //
            Serial.print(".");
        }  
        /* if data is available then receive and print to Terminal */
        while (client.available()) {
            char c = client.read();
            Serial.write(c);
        }

        /* if the server disconnected, stop the client */
        if (!client.connected()) {
            Serial.println();
            Serial.println("Server disconnected");
            client.stop();
        }
    }
Serial.println("//////////////////////    THE END     /////////////////////");
delay(3000);
}