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Notifications from SimpleBLEPeripheral to SimpleBLECentral (CC2640)

Hello,

When do the notifications get sent exactly? Does it get sent if the Central calls for a write to a characteristic value in the  Peripheral?

What I mean is, say the Central calls for a value update to a characteristic value. The callback for write is called at the peripheral side. But, what if the write callback does not actually change the value of the characteristic. Instead it just does, something like a print of the new value sent from the central. In such a case, would the notification be sent?

I am talking about a case where the characteristic is something like a command and a write is not actually meant to change the value, rather it is meant to use the sent value(command) to do some processing.

Regards,

Shyam

  • Hi,

    Notifications are different than characteristic writes/reads. They are a part of the BLE specification. It may be useful for you to review BLE 4.2 Specification Vol 3, part G Section 4.10 "Characteristic Value Notification" to read more about notifications.

    To when they are sent, first notifications must be enabled, but they are sent asynchronously.
  • Hello,
    Thank you for the reply.
    I have enabled the notifications and am aware that the notifications are sent asynchronously.
    My question was whether the notification would be sent if : "write callback does not actually change the value of the characteristic"

    If I call the GATTServApp_ProcessCharCfg() , will the noification be sent irrespective of whether i have changed the characteristic value or not (IF I HAVE ENABLED NOTIFICATION, of course, And so has the central).