RE: Send a response directly in the same "connection interval" in Bluetooth

QuentinD — Wed, 24 Feb 2021 14:53:00 GMT

Thank you very much for your explanations :)

RE: Send a response directly in the same "connection interval" in Bluetooth

Vidar Berg — Wed, 24 Feb 2021 14:46:02 GMT

This is the main reason we are using Write commands and not Write requests to transfer FW images our BLE DFU protocol. It's simply too slow.

You can read more about our dfu protocol here if you are interested: DFU protocol

RE: Send a response directly in the same "connection interval" in Bluetooth

daviddedwin — Tue, 23 Feb 2021 18:19:12 GMT

Getting an application level ACK using a GATT procedure will not be possible in the same connection interval as there is not enough time for the response to get to the event before it closes (it has only 150us) and additionally the Radio buffer needs to be filled for the response before the event starts which would be impossible , so the short answer to your question is No.

However you are getting the Radio level acknowledgements for the Write Commands and the Handle Value Notifications and you can use them as acknowledgements.
Handle Value Notifications will generate a BLE_GATTS_EVT_HVN_TX_COMPLETE and Write Command will generate a BLE_GATTC_EVT_WRITE_CMD_TX_COMPLETE.

This means that you can send a lot of your packets and then get the acknowledgement events as they arrive. This will allow you to send a lot lot of packets in a single event and also get acks in the same event. Will this work for you ?