LWiFiClient c;

Initiate the setup() function

Now the setup() function is defined, to start the various services that will be used by the sketch.

1. Initiates Wi-Fi communication followed by Serial communication with a baud rate of 115200.

   void setup() 
   {
     LWiFi.begin(); 
     Serial.begin(115200);

2. Prints a message “Connecting to AP” to the serial output and in a while loop calls the connect() method of the LWiFi class every second until a connection is established.

     // keep retrying until connected to AP 
     Serial.println("Connecting to AP"); 
     while (0 == LWiFi.connect(WIFI_AP, LWiFiLoginInfo(WIFI_AUTH, WIFI_PASSWORD))) 
     { 
       delay(1000); 
     } 

3. In a while loop attempts to connect to the website once a second, by calling the connect() method of the LWiFiClient object c until a connection is established.

     // keep retrying until connected to website 
     Serial.println("Connecting to website");
     while (0 == c.connect(SITE_URL, 80))
     {
       Serial.println("Re-Connecting to website");
       delay(1000);
     } 

4. Sends the HTTP GET request. Here you’ll implement one of the three options for using the HTTP GET method in your Arduino sketch, as follows:
   1. Send a HTTP GET request to the defined URL using this code.

        Serial.println("send HTTP GET request");
        c.println("GET / HTTP/1.1");
        c.println("Host: " SITE_URL);
        c.println("Connection: close");
        c.println();

   2. Obtain a JSON object from the server using HTTP GET method, using this code.
   • Replace the SITE_URL (set up in Define the variables that configure the AP settings) with the following:

     #define SITE_URL "download.labs.mediatek.com "  //configure the hostname

   • Send a HTTP GET for a specific file to the defined URL using this code:

       Serial.println("send HTTP GET request");
       c.println("GET /package_mtk_linkit_index.json HTTP/1.1");//modify the GET path
       c.println("Host: " SITE_URL);
       c.println("Connection: close");
       c.println();

   3. Read and download a file from the server using HTTP GET method, using this code:
   • Replace the SITE_URL (set up in Define the variables that configure the AP settings) with the following:

     #define SITE_URL "textfiles.com"            //configure the hostname

   • Send a HTTP GET for a specific file to the defined URL using this code:

       // send HTTP request, ends with 2 CR/LF
       Serial.println("Connected. Sending HTTP GET Request ....");
       c.println("GET /100/ad.txt HTTP/1.1"); //modify the GET path
       c.println("Host: " SITE_URL);
       c.println("Connection: close");
       c.println();

   Once one of these options is implemented in your setup() function, proceed with the rest of the code.
   
   
5. The HTTP POST method.

   char thisData[128];                     //create a char array for sending data 
   //send the header
   c.println("POST / HTTP/1.1");           //define POST path
    
   c.println("Host: " SITE_URL);           //define hostname  
   c.println("Connection: close");
    
   c.println(“Content-Type: application/json”);     //define Content-Type 
   c.print("Content-Length: ");                     //define Content-Length 
   c.println(strlen(thisData));
   c.println();
    
   // send the body (variables)
   c.print(thisData);

6. Waits for the server to respond. Checks in the while loop if the LWiFiClient object is still available every 100 milliseconds.

     Serial.println("waiting HTTP response:");
     while (!c.available())
     {
       delay(100);
     }

Add the loop() function

Declare a global boolean variable that will be used later to indicate if the connection was disconnected.

boolean disconnectedMsg = false;

  // Make sure we are connected, and dump 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);
}

#define SITE_URL "httpbin.org"     //configure the hostname

int tempF = 50;
int tempC = 15;
int pressure = 15;
int humidity = 15;  

//build JSON method
String buildJson() {
  String data = "{";
  data+="\n";
  data+= "\"d\": {";
  data+="\n";
  data+="\"temperature (F)\": ";
  data+=tempF;
  data+= ",";
  data+="\n";
  data+="\"temperature (C)\": ";
  data+=tempC;
  data+= ",";
  data+="\n";
  data+="\"pressure\": ";
  data+=pressure;
  data+= ",";
  data+="\n";
  data+="\"humidity\": ";
  data+=humidity;
  data+="\n";
  data+="}";
  data+="\n";
  data+="}";
  return data;
}

  // send HTTP request, ends with 2 CR/LF
  String PostData = buildJson();
  Serial.println("Connected. Sending HTTP GET Request ...."); 
  c.println("POST /post HTTP/1.1");  //modify the POST path
  c.println("Host: " SITE_URL);
  c.println("Connection: close");
  c.print("Content-Length: ");
  c.println(PostData.length());
  c.println();
  c.println(PostData);  //send the HTTP POST body
   
  // waiting for server response
  Serial.println("waiting HTTP response:");
  while (!c.available())
  {
    delay(100);
  }
}