.. _set_on_mastering_need:

set_on_mastering_need
------------------------------------------
This function registers a callback function that automatically checks whether the robot’s axes have been twisted by an external force. Use it to run your own code automatically when this event occurs.

**Definition** |br|
``DRFLEx.h`` within class `CDRFLEx`, public section

.. code-block:: cpp

    void set_on_mastering_need(TOnMasteringNeedCB pCallbackFunc) { 
        _set_on_mastering_need(_rbtCtrl, pCallbackFunc); 
    };

**Parameter**

.. list-table::
   :widths: 20 20 20 40
   :header-rows: 1

   * - **Parameter Name**
     - **Data Type**
     - **Default Value**
     - **Description**
   * - pCallbackFunc
     - :ref:`TOnMasteringNeedCB <cb_tonmasteringneedcb>`
     - -
     - Refer to definition of callback function

**Return** |br|
None

**Example**

.. code-block:: cpp

   std::atomic<bool> g_bNeedHoming(false);

   void OnMasteringNeedCB()
   {
       // Request homing from the main loop
       g_bNeedHoming = true;
   }

   drfl.set_on_mastering_need(OnMasteringNeedCB);

   // Main loop: call move_home outside the callback
   while (true) {
       if (g_bNeedHoming) {
           g_bNeedHoming = false;
           // Starts the homing mode for the alignment of the robot’s axes
           drfl.move_home(MOVE_HOME_MECHANIC, 1);
       }
       std::this_thread::sleep_for(std::chrono::milliseconds(100));
   }

When registered, this callback is executed automatically  
if the controller detects **axis misalignment caused by external force**.  
The callback sets a flag, and the main loop then starts the **homing procedure** to realign all robot joints,  
ensuring proper position calibration before resuming normal operation. Call move_home outside the callback; see :ref:`Rules for callback functions <callback_rules>`.