Smart Heart Monitoring System

#include <LTask.h>
#include <LWiFi.h>
#include <LWiFiClient.h>
#include <LFlash.h>
#include <LSD.h>
#include <LStorage.h>

#define WIFI_AP "NETGEAR" //connect to your Wifi network
#define WIFI_PASSWORD "123456"  //change the password
#define WIFI_AUTH LWIFI_WPA  // choose from LWIFI_OPEN, LWIFI_WPA, or LWIFI_WEP.
#define SITE_URL "http://52.91.67.155:8080/"
//#define Drv LFlash          // use Internal 10M Flash
#define Drv LSD           // use SD card
int i =0, sensor;
String val ="";
String lecg , ecg_data;
LWiFiClient c;
String dataStringfnl ;
void setup()
{
   //Serial.begin(9600);
Serial.begin(115200);

    while(!Serial.available());         // input any thing to start
Serial.println("1");


    Serial.print("Initializing SD card...");
    // make sure that the default chip select pin is set to
    // output, even if you don't use it:
    pinMode(10, OUTPUT);

    // see if the card is present and can be initialized:
    LTask.begin();
    Drv.begin();
    Serial.println("card initialized.");
    LFile dataFile = Drv.open("datalog.txt", FILE_WRITE);
     // make a string for assembling the data to log:
  String dataString = "";

  // read value from sensor and append to the string:
  for(i=0;i<500;i++){
     sensor = analogRead(A0);
      dataString += String(sensor);
      dataString += String(",");
      //dataFile.println(String(sensor));
      //dataString += "\n";
  }
  
Serial.println(dataString);
 
    dataFile.close();  
  Serial.println("data acquired");
 
  LWiFi.begin();
  // keep retrying until connected to AP
 Serial.println("Connecting to AP");
  while (0 == LWiFi.connect(WIFI_AP, LWiFiLoginInfo(WIFI_AUTH, WIFI_PASSWORD)))
  {
    delay(1000);
    Serial.println("2");
  }
String ecg_data = "ecg_data="+ dataString;
String lecg = String(ecg_data.length());
Serial.println(ecg_data);
  // keep retrying until connected to website
  Serial.println("Connecting to WebSite");
  while (0 == c.connect(SITE_URL, 8080))
  {
    Serial.println("Re-Connecting to WebSite");
    delay(1000);
  }
Serial.println("3");
  // send HTTP request, ends with 2 CR/LF
  Serial.println("send HTTP POST request");
  c.println("POST / HTTP/1.1");
  c.println("Host: " SITE_URL);
  c.println("Connection: keep-alive");
  c.println("Content-Type: application/x-www-form-urlencoded");
   c.print("Content-Length: ");
   c.println(ecg_data.length());
   c.println();
   c.println(ecg_data);
   
  // waiting for server response
  Serial.println("waiting HTTP response:");
  while (!c.available())
  {
    delay(100);
  }
  Serial.println("4");
}

boolean disconnectedMsg = false;



void loop()
{
  // Make sure we are connected, and the response content to Serial
  while (c)
  {
    int v = c.read();
    if (v != -1)
    {
      Serial.print((char)v);
    }
    else
    {
      Serial.println("no more content, disconnect");
      c.stop();
      while (1)
      {
        delay(1);
      }
    }
  }

  if (!disconnectedMsg)
  {
    Serial.println("disconnected by server");
    disconnectedMsg = true;
  }
  delay(500);
}