[FreeRTOS] Summary of common functions

1. xTaskCreate()：

   • usage:

   xTaskCreate(taskFunction, taskName, stackSize, parameters, priority, taskHandle)
   

   • parameter:
     • taskFunction: Task function, that is, the entry function of the task.
     • taskName: The name of the task.
     • stackSize: The size of the task stack.
     • parameters: The parameter passed to the task function.
     • priority: The priority of the task.
     • taskHandle: Task handle, used to refer to the created task.
   • Return value: Return if the task is created successfully, pdPASSotherwise return errCOULD_NOT_ALLOCATE_REQUIRED_MEMORY.

2. vTaskDelay()：

   • usage:

vTaskDelay(delay)

• parameter:
  • delay: Delay time, in ticks of the system clock.
• Return value: None.

3. xQueueCreate()：

   • Usage: xQueueCreate(queueLength, itemSize)
   • parameter:
     • queueLength: The length of the queue, that is, the number of elements that can be stored.
     • itemSize: The size of each queue element.
   • Return value: If the queue is successfully created, a handle to the queue is returned, otherwise NULL is returned.

4. xQueueSend()：

   • usage:

xQueueSend(queueHandle, item, waitTime)

• parameter:
  • queueHandle: The handle to the queue.
  • item: The data to send.
  • waitTime: The time to wait for the queue to be available, in ticks of the system clock.
• Return value: Return if the data was successfully sent to the queue, pdPASSotherwise return errQUEUE_FULL.

5. xQueueReceive()：
   • usage:

xQueueReceive(queueHandle, buffer, waitTime)

• parameter:
  • queueHandle: The handle to the queue.
  • buffer: Buffer for receiving data.
  • waitTime: The time to wait for the queue to be available, in ticks of the system clock.
• Return value: Return if the data is successfully received, pdPASSotherwise return errQUEUE_EMPTY.

6. xSemaphoreCreateBinary()：
   • usage:

xSemaphoreCreateBinary()

• Parameters: none
• Return value: If the binary semaphore is created successfully, it returns a handle pointing to the semaphore, otherwise it returns NULL.

7. xSemaphoreTake()：
   • usage:

xSemaphoreTake(semaphoreHandle, waitTime)

• parameter:
  • semaphoreHandle: Handle to the semaphore.
  • waitTime: The time to wait for the semaphore to be available, in ticks of the system clock.
• Return value: Return if the semaphore is successfully obtained, otherwise pdPASSreturn errQUEUE_EMPTY.

8. xSemaphoreGive()：
   • usage:

xSemaphoreGive(semaphoreHandle)

• parameter:
  • semaphoreHandle: Handle to the semaphore.
• Return value: Return if the semaphore is successfully released, pdPASSotherwise return errQUEUE_FULL.

9. xEventGroupCreate()：
   • usage:

xEventGroupCreate()

• Parameters: none
• Return value: If the event group is created successfully, it returns a handle pointing to the event group, otherwise it returns NULL.

10. xEventGroupSetBits()：
    • usage:

xEventGroupSetBits(eventGroupHandle, eventBits)

• parameter:
  • eventGroupHandle: Handle to the event group.
  • eventBits: The event bit to set.
• Return value: The event bit that was set.

11. xEventGroupWaitBits()：
    • usage:

    xEventGroupWaitBits(eventGroupHandle, bitsToWaitFor, clearOnExit, waitForAllBits, waitTime)
    

    • parameter:
      • eventGroupHandle: Handle to the event group.
      • bitsToWaitFor: Waiting event bit.
      • clearOnExit: Whether to clear the event bit when exiting the wait.
      • waitForAllBits: Whether to wait for all event bits to be set.
      • waitTime: The time to wait for the event bit to be set, in ticks of the system clock.
    • Return value: The event bit that was set.