BLE Sniffer shows ATT write but no UUIDS?

RE: BLE Sniffer shows ATT write but no UUIDS?

bao008 — Thu, 16 May 2024 02:12:16 GMT

I have also encountered this problem. My 52832 is connected to BLE4.0, and the MTU is 23B. How did you solve it? Thank you!

RE: BLE Sniffer shows ATT write but no UUIDS?

Kenneth — Tue, 05 Apr 2022 09:33:28 GMT

The sniffer will typically only show what is on-air, and the UUID is not sent on-air during normal write, read and notifications. However I do believe that if during the same connection there was a database discovery prior, the sniffer software may be able to find which UUID the handle belong to, and display it alongside the handle.

Kenneth

RE: BLE Sniffer shows ATT write but no UUIDS?

AndrewMohawk — Mon, 04 Apr 2022 17:22:10 GMT

Hi Kenneth,

I am not following how this would relate to why I dont see the UUIDs. If you look at this guide here: https://daniellethurow.com/blog/2021/9/22/using-adafruits-bluetooth-sniffer

You see the following screenshot (and is similar across many other guides as well):

RE: BLE Sniffer shows ATT write but no UUIDS?

Kenneth — Mon, 04 Apr 2022 12:31:34 GMT

The GATT database server will have a lot of services and characteristics with different UUID's. Typically when a peer is doing a database discovery it will receive all the UUID's with a unique 16-bit handle for each "entry" in the GATT database, the handle is typically an incrementally ordered value for each service and characteristic in the GATT database. All communication (write, read, notifications) will be done using the 16-bit handle, this according to BT specifications.

Kenneth