Library Description

Library provides functions for comunication via UART module, and contol over RE and DE pins.

Key functions:

• void rs4856_write_byte ( uint8_t input ) - Write single byte of data
• uint8_t rs4856_read_byte( ) - Read single byte of data
• uint8_t rs4856_byte_ready ( ) - .

Examples description

The application is composed of three sections :

• System Initialization - Intializes UART module
• Application Initialization - Driver intialization
• Application Task - Choose one mode (read or write) of task. If you reading it checks if data is ready to be read and then reads one byte and if you are wiriting send data via UART.

void application_task ( )
{
    char tmp;

    if ( app_mode == APP_MODE_RECEIVER )
    {
        // RECEIVER - UART polling 
        rs4856_re_pin_set( RS4856_PIN_STATE_LOW );
        rs4856_de_pin_set( RS4856_PIN_STATE_LOW );

        drdy_flag = rs4856_byte_ready( );

        if ( 1 == drdy_flag )
        {
            tmp = rs4856_read_byte( );
            mikrobus_logWrite( &tmp, _LOG_BYTE );
        }
    }
    else
    {
        // TRANSMITER - TX each 2 sec
        rs4856_re_pin_set( RS4856_PIN_STATE_HIGH );
        rs4856_de_pin_set( RS4856_PIN_STATE_HIGH );
      
        for ( tmp = 0; tmp < 9; tmp++ )
        {
            rs4856_write_byte( demo_message_data[ tmp ] );
        }
        Delay_ms( 2000 );
    }
}

Other mikroE Libraries used in the example:

• UART

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.