What are the STM32WB Custom Template Notify functions for?

[mbedt]

I've noticed that when I create a notify characteristic, two functions are created each time: one is called Custom_<name of char>_Send_Notication(), the other is Custom_<name of char>_Update_Char(). What is the difference? They both end up calling the same function, Custom_STM_App_Update_Char(CUSTOM_STM_PINGRESPONSE, (uint8_t *)NotifyCharData), but point to different arrays - why different arrays / what is their purpose?

[STTwo-32 · Accepted solution]

Hello @mbedt 

The functions Custom_<name of char>_Send_Notication()and Custom_<name of char>_Update_Char()serve different purposes in the context of handling BLE characteristics:

1. Custom__Send_Notification():

   • This function is specifically designed to send notifications to the client. Notifications are a way for the server to inform the client about changes in the characteristic value without the client having to request it.
   • The function typically prepares the data to be sent and calls Custom_STM_App_Update_Char with the appropriate parameters to trigger the notification.

2. Custom__Update_Char():

   • This function is used to update the characteristic value on the server side. It does not necessarily trigger a notification to the client. Instead, it updates the value stored in the server's GATT database.
   • This function also calls Custom_STM_App_Update_Char to update the characteristic value, but it may be used in contexts where a notification is not required.

More details are available on the chapter 2.5.6 of the Introduction to STM32WB Bluetooth® Low Energy wireless interface - Application note 

Best Regards.

STTwo-32