BT Click

BT Click is a compact add-on board targeted for applications that require both Bluetooth Smart and Classic connectivity. This board features the BT121, a dual-mode Bluetooth Smart Ready module solution that gives unparalleled flexibility to integrate both Bluetooth Smart and Bluetooth Basic Rate/Enhanced Data Rate (BR/EDR) wireless technologies from Silicon Labs.

Click Product page

Click library

• Author : Stefan Filipovic
• Date : Jun 2021.
• Type : UART type

Software Support

We provide a library for the BT Click as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.

Package can be downloaded/installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Library Description

This library contains API for BT Click driver.

Standard key functions :

• bt_cfg_setup Config Object Initialization function.

  void bt_cfg_setup ( bt_cfg_t *cfg );

• bt_init Initialization function.

  err_t bt_init ( bt_t *ctx, bt_cfg_t *cfg );

• bt_default_cfg Click Default Configuration function.

  err_t bt_default_cfg ( bt_t *ctx );

Example key functions :

• bt_set_local_name This function sets the local name of the device.

  err_t bt_set_local_name ( bt_t *ctx, char *name );

• bt_send_package This function sends a data package to the Click board.

  err_t bt_send_package ( bt_t *ctx, bt_package_t pkg );

• bt_read_package This function waits for the command or event type of message to arrive and then reads the complete message and stores it to pkg structure.

  err_t bt_read_package ( bt_t *ctx, bt_package_t *pkg );

Example Description

This example demonstrates the use of BT Click board.

The demo application is composed of two sections :

Application Init

Initializes the driver and configures the Click board.

void application_init ( void )
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    bt_cfg_t bt_cfg;    /**< Click config object. */

    /** 
     * Logger initialization.
     * Default baud rate: 115200
     * Default log level: LOG_LEVEL_DEBUG
     * @note If USB_UART_RX and USB_UART_TX 
     * are defined as HAL_PIN_NC, you will 
     * need to define them manually for log to work. 
     * See @b LOG_MAP_USB_UART macro definition for detailed explanation.
     */
    LOG_MAP_USB_UART( log_cfg );
    log_init( &logger, &log_cfg );
    Delay_ms ( 100 );
    log_info( &logger, " Application Init " );

    // Click initialization.

    bt_cfg_setup( &bt_cfg );
    BT_MAP_MIKROBUS( bt_cfg, MIKROBUS_1 );
    err_t init_flag  = bt_init( &bt, &bt_cfg );
    if ( UART_ERROR == init_flag ) 
    {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    }

    log_printf( &logger, " Default Config : %s\r\n\n", ( char * )
                         ( BT_OK == bt_default_cfg ( &bt ) ? "OK" : "FAIL" ) );

    log_printf( &logger, " Set Local Name : %s\r\n\n", ( char * )
                        ( BT_OK == bt_set_local_name ( &bt, "MikroE - BT Click" ) ? "OK" : "FAIL" ) );

    log_printf( &logger, " Delete Bondings : %s\r\n\n", ( char * )
                        ( BT_OK == bt_delete_bondings ( &bt ) ? "OK" : "FAIL" ) );

    log_printf( &logger, " Set Bondable Mode : %s\r\n\n", ( char * )
                        ( BT_OK == bt_set_bondable_mode ( &bt, BT_SM_SET_BONDABLE_ALLOWED ) ? "OK" : "FAIL" ) );

    log_printf( &logger, " Set GAP Mode : %s\r\n\n", ( char * )
                        ( BT_OK == bt_set_gap_mode ( &bt, BT_GAP_MODE_CONNECTABLE, 
                                                          BT_GAP_MODE_DISCOVERABLE, 
                                                          BT_GAP_MODE_NOT_LIMITED ) ? "OK" : "FAIL" ) );

    log_printf( &logger, " RFCOMM Start Server : %s\r\n\n", ( char * )
                        ( BT_OK == bt_rfcomm_start_server ( &bt, BT_RFCOMM_SERVER_DEF_SDP_ID, 
                                                                 BT_RFCOMM_SERVER_DEF_STREAM_DEST ) ? "OK" : "FAIL" ) );

    log_info( &logger, " Application Task " );
}

Application Task

Handles most of the events required for this example, the packages of events not supported in this example will be just displayed on the USB UART. The event handler will display all messages sent from the remote device on the USB UART and send back the predefined response message "DONE". There are two specific commands which can be sent from the remote device: "led blink" - calls bt_led_blink function for a 5 seconds time period. "check buttons" - calls bt_check_buttons function.

void application_task ( void )
{
    bt_event_handler( &bt );
}

Note

We have used the Serial Bluetooth Terminal smartphone application for the test. A smartphone and the Click board must be paired in order to exchange messages with each other.

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on Mikroe github account.

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.BT

Additional notes and informations

Depending on the development board you are using, you may need USB UART Click, USB UART 2 Click or RS232 Click to connect to your PC, for development systems with no UART to USB interface available on the board. UART terminal is available in all MikroElektronika compilers.