I'm having some issues getting NFC to work properly in SDK 3.3.1. The demo apps (snip.nfc.tag_reader and snip.nfc.tag_writer) work properly on my BCM943341 development board. However, these example apps call the wiced_nfc_read_tag and wiced_nfc_write_tag APIs forever in a while (1) loop. I would like to implement these calls in an interrupt-driven fashion, starting by using the two buttons on the demo board. I placed these two calls in a routine assigned to the hardware worker thread as follows - this routine is called once a second and checks the status of the two buttons:
| // Fire up the worker thread for NFC read and write |
| wiced_rtos_register_timed_event( &nfc_worker_event, WICED_HARDWARE_IO_WORKER_THREAD, nfc_worker, 1000, 0 ); |
....
static void nfc_worker ( )
{
wiced_result_t result;
int i;
WPRINT_APP_INFO (("NFC worker called. %d\n", timeout++));
wiced_gpio_output_low( WICED_LED1 );
wiced_gpio_output_low( WICED_LED2 );
// NFC Read
if (start_nfc_read == WICED_TRUE)
{
start_nfc_read = WICED_FALSE;
wiced_gpio_output_high( WICED_LED2 );
WPRINT_APP_INFO (("Starting NFC Read.\n"));
/* Reset the buffer_length variable. Note that this is used for both input and output */
buffer_length = NFC_DATA_LENGTH;
/* Wait for, and read, and NFC tag */
result = wiced_nfc_read_tag( buffer, &buffer_length, NFC_READ_TIMEOUT );
if ( result != WICED_SUCCESS )
{
if ( result == WICED_TIMEOUT )
{
WPRINT_APP_INFO( ( "Tag not detected\n" ) );
}
return;
}
WPRINT_APP_INFO( ( "Received %lu bytes:\n", buffer_length ) );
/* Print the contents of the NFC tag */
for ( i = 0; i < buffer_length; i++ )
{
/* Check if the character is printable, otherwise use hex notation*/
if ( buffer[ i ] >= 0x20 && buffer[ i ] <= 0x7E )
{
WPRINT_APP_INFO( ( "%c", buffer ) );
}
else
{
WPRINT_APP_INFO( ( "\\%02x", buffer ) );
}
}
WPRINT_APP_INFO( ( "\n" ) );
}
else if (start_nfc_write == WICED_TRUE)
{
start_nfc_write = WICED_FALSE;
wiced_gpio_output_high( WICED_LED1 );
WPRINT_APP_INFO (("Starting NFC Write.\n"));
WPRINT_APP_INFO( ("\nWaiting for tag...\n") );
result = wiced_nfc_write_tag( &tag_write_message, NFC_WRITE_TIMEOUT );
if ( result == WICED_SUCCESS )
{
WPRINT_APP_INFO( ("Tag write successful\n") );
/* Delay for a short time to allow tag to be removed */
//wiced_rtos_delay_milliseconds( 1000 );
}
else if ( result == WICED_TIMEOUT )
{
WPRINT_APP_INFO( ( "Tag not detected\n" ) );
}
}
}
Ultimately the hardware works and I can read or write an NFC tag but it only works once: It gets stuck somewhere in the above routine and the design crashes.
Is there a recommended way of calling the NFC tag read and write API? The NFC stuff appears to run within a separate thread of its own.
