event_groups.h More...

event_groups.h

   EventBits_t xEventGroupClearBits( EventGroupHandle_t xEventGroup, const EventBits_t uxBitsToClear );

Clear bits within an event group. This function cannot be called from an interrupt.

Parameters

xEventGroup	The event group in which the bits are to be cleared.
uxBitsToClear	A bitwise value that indicates the bit or bits to clear in the event group. For example, to clear bit 3 only, set uxBitsToClear to 0x08. To clear bit 3 and bit 0 set uxBitsToClear to 0x09.

Returns: The value of the event group before the specified bits were cleared.

Example usage:

  #define BIT_0 ( 1 << 0 )
  #define BIT_4 ( 1 << 4 )

  void aFunction( EventGroupHandle_t xEventGroup )
  {
  EventBits_t uxBits;

    // Clear bit 0 and bit 4 in xEventGroup.
    uxBits = xEventGroupClearBits(
                            xEventGroup,    // The event group being updated.
                            BIT_0 | BIT_4 );// The bits being cleared.

    if( ( uxBits & ( BIT_0 | BIT_4 ) ) == ( BIT_0 | BIT_4 ) )
    {
        // Both bit 0 and bit 4 were set before xEventGroupClearBits() was
        // called.  Both will now be clear (not set).
    }
    else if( ( uxBits & BIT_0 ) != 0 )
    {
        // Bit 0 was set before xEventGroupClearBits() was called.  It will
        // now be clear.
    }
    else if( ( uxBits & BIT_4 ) != 0 )
    {
        // Bit 4 was set before xEventGroupClearBits() was called.  It will
        // now be clear.
    }
    else
    {
        // Neither bit 0 nor bit 4 were set in the first place.
    }
  }