Library Description

Initializes and defines UART bus driver, and defines drivers for reading, writing and check for new data between RS485 Isolator 2 clicks. User can also enable or disable both transmiter and receiver, and to invert receiving or transmitting data.

Key functions:

• void rs485isolator2_write_byte ( uint8_t input ) - Writes single byte.
• uint8_t rs485isolator2_read_byte( ) - Read received byte.
• uint8_t rs485isolator2_byte_ready ( ) - Checks is there a new byte received.

Examples description

The application is composed of three sections :

• System Initialization - Initializes UART module and sets RST, CS, PWM and INT pins as an output.
• Application Initialization - Initalizes UART driver and makes an initial log.
• Application Task - (code snippet) This example covers two cases. First case (receiver mode): checks for new data and, if available, reads one byte from rx buffer. Second case (transmiter mode): writes message via UART. An example is setup for noninverted data transmision and receiving.

void application_task ( )
{
    char tmp;
    uint8_t drdy_flag;

    if ( app_mode == APP_MODE_RECEIVER )
    {
        // RECEIVER - UART polling 
        rs485isolator2_re_state( RS485ISOLATOR2_ENABLE_RE );
        drdy_flag = rs485isolator2_byte_ready( );

        if ( 1 == drdy_flag )
        {
            tmp = rs485isolator2_read_byte( );
            mikrobus_logWrite( &tmp, _LOG_BYTE );
        }
        rs485isolator2_re_state( RS485ISOLATOR2_DISABLE_RE );
    }
    else
    {
        // TRANSMITER - TX each 2 sec
        rs485isolator2_de_state( RS485ISOLATOR2_ENABLE_DE );
        for ( tmp = 0; tmp < demo_message_lenght; tmp++ )
        {
            rs485isolator2_write_byte( demo_message_data[ tmp ] );
        }
        rs485isolator2_de_state( RS485ISOLATOR2_DISABLE_DE );
        Delay_ms( 2000 );
    }
}

Other mikroE Libraries used in the example:

• UART
• Conversion

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.