Library Description

Library provides function for initializing device and control over GPIO pin states.

Key functions:

• void ismrx2_initialize_device ( void ) - Function for waking up device and reseting it
• uint8_t ismrx2_get_data_pin_state ( void ) - Function for getting data pin pin state

Examples description

The application is composed of three sections :

• System Initialization - Initialize GPIO pins and LOG module
• Application Initialization - Initilize device
• Application Task - Wait for data pin to go down and starts sampling and waiting for sync word if it's received collect data to buffer till it receive 0 byte

void application_task ( )
{
//---------------------------------------------------------Manchester example
    if ( MANCHESTER_EXAMPLE == example_type )
    {
        if ( ISMRX2_PIN_STATE_LOW == ismrx2_get_data_pin_state() )
        {
            //Collecting data till timeout
            sample_collecter();
            //Filtering data for validation
            filter_sample();
            
            if ( ISMRX2_DEV_OK == valid_data )
            {
                //Extracting manchester data
                man_sort();
                //Extracting bit data
                bit_sort();
                //Extracting decoded data
                data_sort();
                //Logs result if valid data received ( first byte 0xFF )
                if ( ISMRX2_DEV_OK == valid_data )
                {
                    data_tmp =  &data_buf[ 1 ];
                    mikrobus_logWrite( " - RX data: ", _LOG_TEXT );
                    mikrobus_logWrite( data_tmp, _LOG_LINE );
                    mikrobus_logWrite( "*********************", _LOG_LINE );
                }

                Delay_ms( 50 );
            }
            //Resets every counter and flag
            reset_to_default(  );
        }
    }
//-----------------------------------------------------------------------------

//--------------------------------------------------------------- Basic example
    if ( DEFAULT_EXAMPLE == example_type )
    {
        if ( ISMRX2_PIN_STATE_LOW == ismrx2_get_data_pin_state() )
        {
            state = read_rf_data( &data_buf[ 0 ] );
            if ( ISMRX2_DEV_OK == state )
            {
                mikrobus_logWrite( " - RX data: ", _LOG_TEXT );
                mikrobus_logWrite( data_buf, _LOG_LINE );
                mikrobus_logWrite( "*********************", _LOG_LINE );
                Delay_ms( 50 );
            }
        }
    }
//-----------------------------------------------------------------------------
}

Additional Functions :

• uint8_t read_rf_data ( uint8_t *read_buff ) - Function for reading data from RF antenna till you get 0 byte.
• void min_max_check ( uint8_t check_b ) - Function for getting max and min sample data values.
• void bit_sort ( ) - Extracting bit data from manchester buffer.
• void data_sort ( ) - Extracting data from bit buffer.
• void man_set_data ( uint16_t smp_cnt, uint8_t man_data ) - Function that sets data to manchester buffer
• void man_sort ( ) - Function for extracting data from sample buffer.
• void sample_collecter ( ) - Collecting data from pin.
• void filter_sample ( ) - Filtering collected data.
• void reset_to_default ( ) - Resets flags and counters to default values.

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.