crDELAY

croutine. More...

croutine.

h

crDELAY( CoRoutineHandle_t xHandle, TickType_t xTicksToDelay );

Delay a co-routine for a fixed period of time.

crDELAY can only be called from the co-routine function itself - not from within a function called by the co-routine function. This is because co-routines do not maintain their own stack.

Parameters
xHandleThe handle of the co-routine to delay. This is the xHandle parameter of the co-routine function.
xTickToDelayThe number of ticks that the co-routine should delay for. The actual amount of time this equates to is defined by configTICK_RATE_HZ (set in FreeRTOSConfig.h). The constant portTICK_PERIOD_MS can be used to convert ticks to milliseconds.

Example usage:

// Co-routine to be created.
void vACoRoutine( CoRoutineHandle_t xHandle, UBaseType_t uxIndex )
{
// Variables in co-routines must be declared static if they must maintain value across a blocking call.
// This may not be necessary for const variables.
// We are to delay for 200ms.
static const xTickType xDelayTime = 200 / portTICK_PERIOD_MS;
// Must start every co-routine with a call to crSTART();
crSTART( xHandle );

for( ;; )
{
   // Delay for 200ms.
   crDELAY( xHandle, xDelayTime );

   // Do something here.
}

// Must end every co-routine with a call to crEND();
crEND();
}