RN4870 click

RN4870 click carries the RN4870 Bluetooth® 4.2 low energy module from Microchip.The click is designed to run on a 3.3V power supply. It uses ASCII Command Interface over UART for communication with target microcontroller, with additional functionality provided by the following pins on the mikroBUS™ line: RST, CS, and INT.

click Product page

Click library

• Author : MikroE Team
• Date : jun 2020.
• Type : UART GSM/IOT type

Software Support

We provide a library for the Rn4870 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 form compilers IDE(recommended way), or downloaded from our LibStock, or found on mikroE github account.

Library Description

This library contains API for Rn4870 Click driver.

Standard key functions :

• Config Object Initialization function.

  void rn4870_cfg_setup ( rn4870_cfg_t *cfg );

• Initialization function.

  RN4870_RETVAL rn4870_init ( rn4870_t ctx, rn4870_cfg_t cfg );

Example key functions :

• This function gets message from 'void rn4870_receive function if flag was set. This function replaces '*' (character with end of string) with '0x00' and stores received message to process_buffer

  uint8_t rn4870_read ( rn4870_t ctx, uint8_t process_buffer );

• The function receives character by waits for '#' - character to start parsing message, waits for '*' - character to stop parsing message and sets flag if whole and properly formated message is received.

  void rn4870_receive ( rn4870_t *ctx, char tmp );

• The function connects to slave device with desired register address by secures the connection and entering data stream mode.

  void rn4870_connect ( rn4870_t ctx, char p_addr );

Examples Description

This example reads and processes data from RN4870 clicks.

The demo application is composed of two sections :

Application Init

Initializes UART driver. Initializes device and parser.

void application_init ( void )
{
    log_cfg_t log_cfg;
    rn4870_cfg_t cfg;

    /** 
     * 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 );
    log_info( &logger, "---- Application Init ----" );

    //  Click initialization.

    rn4870_cfg_setup( &cfg );
    RN4870_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    rn4870_init( &rn4870, &cfg );

    dev_type = RN4870_DEVICETYPE_MASTER;

    if ( dev_type == RN4870_DEVICETYPE_MASTER )
    {
        rn4870_initialize( &rn4870, &RN4870_ADDR_MASTER[ 0 ] );
    }
    else if ( dev_type == RN4870_DEVICETYPE_SLAVE )
    {
        rn4870_initialize( &rn4870, &RN4870_ADDR_SLAVE[ 0 ] );
        ptr = &receive_buffer[ 7 ];
    }

    memset( &rn4870.device_buffer, 0, 255 );
    log_printf( &logger, " >>> app init done <<<  \r\n" );
}

Application Task

If 'MASTER' - connects to 'SLAVE', sends message and disconnects. If 'SLAVE' - waits for connect request and message from 'MASTER' and LOGs received message.

void application_task ( void )
{
    rn4870_process(  );
    if ( dev_type == RN4870_DEVICETYPE_MASTER )
    {
        rn4870_connect( &rn4870, &RN4870_ADDR_SLAVE[ 0 ] );
        log_printf( &logger, ">>> sending data  <<<\r\n" );
        rn4870_send( &rn4870, RN4870_MTYPE_MSG, RN4870_DTYPE_STRING, RN4870_ID_MASTER, &message_payload[ 0 ] );
        rn4870_disconnect( &rn4870 );
    }
    else if ( dev_type == RN4870_DEVICETYPE_SLAVE )
    {
        msg_flag = rn4870_read( &rn4870, &receive_buffer[ 0 ] );

        if ( msg_flag == 1 )
        {
            log_printf( &logger, ">>> data received <<<\r\n" );
            log_printf( &logger, ">>> data : " );
            log_printf( &logger, "%s\r\n", ptr );     
        }
    }
}  

The full application code, and ready to use projects can be installed directly form compilers IDE(recommneded) or found on LibStock page or mikroE GitHub accaunt.

Other mikroE Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.Rn4870

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. The terminal available in all Mikroelektronika compilers, or any other terminal application of your choice, can be used to read the message.