The difference between bt_gatt_notify and bt_gatt_notify_cb

[Junbo-Zheng]

I am confused about the two functions for between bt_gatt_notify and bt_gatt_notify_cb. I have checked some information, but I still don't understand the difference. Let me talk about my understanding first, If I have something wrong with the description, I hope I can get a correct explanation:

1. The meaning of the bt_gatt_notify is just to put data in the tx queue of the bluetooth stack. If the queue is full, it will block. Only when the queue is not full, can refill the data to be sent. In other words , the return value of the bt_gatt_notify function does not actually send the data to the air interface through the bluetooth stack controller.
2. The meaning of the bt_gatt_notify_cb is similar to the above function. For the user, when the callback(bt_gatt_notify_params ---> bt_gatt_complete_func_t) of this function is called, it will indicate us that the data has been sent out in the form of notify via bluetooth stack controller.

Therefore, if want to know whether the data has been sent to the air interface through the bluetooth controller, it is best to use the bt_gatt_notify_cb function and perform subsequent processing in the callback function.

Please correct me if my description is wrong, thank you