https://devzone.nordicsemi.com/f/nordic-q-a/95833/zephyr-rtos-and-some-other-question-on-bleI Have a peripheral over ble I have to question? When the peripherl send a message ,(send a Notify over ble) is possible to know when the device receive the Layer2 ACK ? In this way I can make a mesure of the time I need for the transmittion withen-USTelligent Community 13Thu, 19 Jan 2023 13:36:30 GMThttps://devzone.nordicsemi.com/thread/405688?ContentTypeID=1Thu, 19 Jan 2023 13:36:30 GMT137ad170-7792-4731-bb38-c0d22fbe4515:f56f6459-5548-4519-9330-082ab423d7a8Kenneth[quote user=""]When the peripherl send a message ,(send a Notify&nbsp; over ble) is possible to know&nbsp; when the device&nbsp; receive the Layer2&nbsp; ACK ?[/quote] <p>The answer depends a bit on how low level you want to go, but from the documentation you can find for instance:</p> <p><span>Attribute value changes can be notified using&nbsp;</span><a title="bt_gatt_notify" href="https://docs.zephyrproject.org/3.2.0/connectivity/bluetooth/api/gatt.html#c.bt_gatt_notify"><code><span>bt_gatt_notify()</span></code></a><span>&nbsp;API, alternatively there is&nbsp;</span><a title="bt_gatt_notify_cb" href="https://docs.zephyrproject.org/3.2.0/connectivity/bluetooth/api/gatt.html#c.bt_gatt_notify_cb"><code><span>bt_gatt_notify_cb()</span></code></a><span>&nbsp;where is is possible to pass a callback to be called when it is necessary to know the exact instant when the data has been transmitted over the air.</span></p> [quote user=""]Is possible for&nbsp; a peripheral to be connected from with a Central only if a central have a Particular &quot;Name&quot; ? So I can accept e/o filter the connection ?[/quote] <p>The peripheral can not do filtering on cental device name, the reason thsi is not possible is that there is no information in the packets (scan request and/or connect request) from the central that may provide information about the name of the central device.&nbsp;</p> <p>Kenneth</p> <p></p><div style="clear:both;"></div>