Table of Contents

Overview

The HTTP client library can be used to communicate and exchange data with a HTTP web server. The HTTP client library support two modes:

1. Minimum mode: HTTP client library in minimum mode supports synchronous mode, redirection handling, chunked transfer encoding, proxy and TLS. HTTPCli_LIBTYPE_MIN flag should be used to build the library in minimum mode.
2. Full Mode: HTTP Client library in full mode supports all the features of the minimal mode along with asynchronous mode and content handling and requires RTOS support. HTTPCli_LIBTYPE_FULL flag should be used to build the library in full mode.

Application details

This application demonstrates HTTP Client library APIs for HTTP-based application development in minimum mode. This application demonstrates how to:

• Connect to an access point
• Connect to a HTTP Server with and without proxy
• Do POST, GET, PUT and DELETE
• Parse JSON data

This example requires an Access Point with internet connectivity.

To enable a secure connection, user must add the following code snippets to the HTTP connection section to set the device date and time and configure a certificate.

    SlDateTime\_t dt;
    struct HTTPCli_SecureParams sparams;       
    /* Set current date to validate certificate */
    dt.sl_tm_day = DATE;  
    dt.sl_tm_mon = MONTH; 
    dt.sl_tm_year = YEAR;  
    dt.sl_tm_hour = HOUR;  
    dt.sl_tm_min = MINUTE;  
    dt.sl_tm_sec = SECOND;  
    sl_DevSet(SL_DEVICE_GENERAL_CONFIGURATION, 
    SL_DEVICE_GENERAL_CONFIGURATION_DATE_TIME, 
    sizeof(SlDateTime_t), (unsigned char *)(&dt)); 
    
    /* Security parameters */
    sparams.method.secureMethod = SL_SO_SEC_METHOD_TLSV1_2;
    sparams.mask.secureMask  = SL_SEC_MASK_TLS_RSA_WITH_AES_256_CBC_SHA;
    strncpy(sparams.cafile, SL_SSL_CA_CERT, sizeof(SL_SSL_CA_CERT));
    sparams.privkey[0] = 0;
    sparams.cert[0] = 0;
    sparams.dhkey[0] = 0;  
    HTTPCli_setSecureParams(&sparams);

HTTPCli\_connect function should also be called with the HTTPCli\_TYPE\_TLS option.:

    HTTPCli_connect(&cli, (struct sockaddr *)&addr, HTTPCli_TYPE_TLS, NULL);

User can change the proxy by editing the macros PROXY\_IP and PROXY\_PORT in main.c and defining the symbol USE\_PROXY.

HTTP Client library API details are provided in SDK in the docs folder.

Usage

1. Setup a serial communication application. Open a serial terminal on a PC with the following settings:
   • Port: Enumerated COM port
   • Baud rate: 115200
   • Data: 8 bit
   • Parity: None
   • Stop: 1 bit
   • Flow control: None

2. Edit common.h and modify the values of the below macros for the device to connect to the AP:

   #define SSID_NAME           "<ap_name>"         /* AP SSID */
   #define SECURITY_TYPE       SL_SEC_TYPE_OPEN    /* Security type (OPEN or WEP or WPA*/
   #define SECURITY_KEY        ""                  /* Password of the secured AP */

3. Run the reference application.
   • Open the project in CCS/IAR. Build the application and debug to load to the device, or flash the binary using UniFlash.

4. The device will try to connect to the Access Point and then the HTTP server. Upon successful connection, application will send POST, DELETE, PUT and GET requests and check and parse the response.

Limitations/Known Issues

- HTTP connection timeout is not supported.
- Only IPV4 is supported