What's the CORRECT way to send a Queue message from another module?

Kernel
1

groger57 wrote on Friday, May 01, 2015:

Instead of asking what’s WRONG with my code, can someone please point me to an example, or provide an example, of the correct way to use xQueueSend from a module other than where the queue handle and function handler are defined?

I’m using FreeeRTOS 8.2.0, in IAR EWARM 7.3, on an STM32F4 controller. I am unable to find an example on the entire web that shows this, and it just happens to be giving me a big headache right now.

Thank you…

2

rtel wrote on Friday, May 01, 2015:

It shouldn’t make any difference which module the queue handle is defined in. A queue handle is just a variable, so it can be declared in one C file, and then extern’ed in another C file, just like any other variable.

File1.c


/* Declared globally. */
QueueHandle_t xQueue = NULL;

int main( void )
{
   . . .

   xQueue = xQueueCreate( 5, sizeof( uint32_t ) );

   . . .

   /* Start tasks. */

   . . .


   /* Start scheduler. */
}

void vTask1InFile1( void *pvParameters )
{
uint32_t DataToSend = 0, DataToReceive;
const TickType_t xBlockTime = pdMS_TO_TICKS( 200 );

    for( ;; )
    {
        . . .

        xQueueSend( xQueue, &DataToSend, xBlockTime );

        . . .

        xQueueReceive( xQueue, &DataToReceive, xBlockTime );
    }
}

File2.c


void vTask2InFile2( void *pvParameters )
{
/* Here the queue handle is extern. */
extern QueueHandle_t xQueue;

uint32_t DataToSend = 0, DataToReceive;
const TickType_t xBlockTime = pdMS_TO_TICKS( 200 );

    for( ;; )
    {
        . . .

        xQueueSend( xQueue, &DataToSend, xBlockTime );

        . . .

        xQueueReceive( xQueue, &DataToReceive, xBlockTime );
    }
}

Regards.