Simple app demonstrating the HTTP GET feature of the WiConnect Host Library.

Dependencies:   WiConnect mbed

example.cpp

Committer:
dan_ackme
Date:
2014-11-03
Revision:
11:b7a7a7d3b805
Parent:
6:f6cf38fba1d4

File content as of revision 11:b7a7a7d3b805:

/**
 * @example http_get/example.cpp
 *
 * This is an example of using the http socket API to
 * download a webpage.
 *
 * It works as follows:
 * 1. Instantiate the WiConnect Library
 * 2. Initiate Communication with WiFi Module
 * 3. Issue a HTTP GET request (Note: The module must have valid network credentials See @ref web_setup/example.cpp)
 * 4. Read the HTTP page and print
 * 5. That's it!
 *
 */


/******************************************************************************
 * Example Variables
 */

// the URL of the webpage to GET
#define HTTP_URL "http://mbed.org/"


// This is the name of your WiFi network
// Look for this name in your WiFi settings
// (e.g. your phone's list of WiFi networks in the WiFi settings menu)
// tip: add double-quotes around SSID to add spaces to name
#define NETWORK_SSID "<YOUR SSID>"

// This is the password of your WiFi network
// Leave as empty string (e.g "") to connect to OPEN network
#define NETWORK_PASSWORD "<YOUR PASSWORD>"


/******************************************************************************
 * Includes
 */

// include C library headers
#include <stdio.h> // needed for printf

// include target specific defines
#include "target_config.h"
// include the Wiconnect Host Library API header
#include "Wiconnect.h"




/******************************************************************************
 * Global Defines
 */


// Serial used for printfs to terminal (i.e. NOT used for WiConnect)
static Serial consoleSerial(STDIO_UART_TX, STDIO_UART_RX);



/******************************************************************************
 * Starting point of application
 */
int main(int argc, char **argv)
{
    consoleSerial.baud(115200); // console terminal to 115200 baud

    //-------------------------------------------------------------------------
    // STEP 1: Instantiate WiConnect Library
    //-------------------------------------------------------------------------

    // Setup  wiconnect serial interface configuration
    // Here we only specify the rx buffer size and not rx buffer pointer, this means
    // The serial RX buffer will be dynamically allocated
    SerialConfig serialConfig(WICONNECT_RX_PIN, WICONNECT_TX_PIN, 256, NULL);

    // Instantiate and initialize the Wiconnect library
    // Here we only specify the buffer size and not buffer pointer, this means
    // The internal buffer will be dynamically allocated
    Wiconnect wiconnect(serialConfig, 256, NULL, WICONNECT_RESET_PIN);

    // set the default timeout to 15s as some websites take awhile to respond
    wiconnect.setCommandDefaultTimeout(15000);

    //-------------------------------------------------------------------------
    // STEP 2: Initiate Communication with WiFi Module
    //-------------------------------------------------------------------------

    printf("Initializing WiConnect Library...\r\n");

    // Initialize communication with WiFi module
    if(wiconnect.init(true) != WICONNECT_SUCCESS)
    {
        printf("Failed to initialize communication with WiFi module!\r\n"
                "Make sure the wires are connected correctly\r\n");
        for(;;); // infinite loop
    }
    
    printf("Joining Wi-Fi network: %s\r\n", NETWORK_SSID);
    if(wiconnect.join(NETWORK_SSID, NETWORK_PASSWORD) != WICONNECT_SUCCESS)
    {
        NetworkJoinResult joinResult;
        wiconnect.getNetworkJoinResult(&joinResult);
        printf("Failed to send join command. Join result: %s\r\n", Wiconnect::networkJoinResultToStr(joinResult));
        for(;;); // infinite loop
    }


    //-------------------------------------------------------------------------
    // STEP 3: Issue a HTTP GET request
    //-------------------------------------------------------------------------

    // Initiate a socket with an RX buffer of 256 bytes
    // We're not specifying the rx buffer pointer so that means it's dynamically allocated
    WiconnectSocket socket(256);


    printf("Issuing HTTP Request: %s\r\n", HTTP_URL);

    // Issue HTTP request
    // NOTE: the module must have valid network credentials
    if(wiconnect.httpGet(socket, HTTP_URL) != WICONNECT_SUCCESS)
    {
        printf("Failed to issue HTTP request\r\n");
        for(;;); // infinite loop
    }

    //-------------------------------------------------------------------------
    // STEP 4: Read the HTTP page and print
    //-------------------------------------------------------------------------

    uint8_t *dataPtr;
    uint16_t dataLength;

    // while there's data to read, retreive and print it
    while(socket.read(&dataPtr, &dataLength) == WICONNECT_SUCCESS)
    {
        fwrite(dataPtr, 1, dataLength, stdout);
    }

    //-------------------------------------------------------------------------
    // STEP 5: Done!
    //-------------------------------------------------------------------------

    printf("HTTP GET example has completed!\r\n");

    while(true){} // infinite loop
}