Can't find services using ble_db_discovery_start()

RE: Can't find services using ble_db_discovery_start()

Randy Lee — Thu, 29 May 2025 13:16:21 GMT

Any hints out of this? I'm stumped at this point

RE: Can't find services using ble_db_discovery_start()

Randy Lee — Mon, 05 May 2025 15:11:21 GMT

Attached is a trace of a Samsung tablet (Android) running nRFconnect. I connect to the BP2 device, gather the schema from it and the read a characteristic from it at which point it wants to pair.. Towards the end I've subscribed to the pressure notifications and am receiving those and then disconnect from it. devzone.nordicsemi.com/.../nRFconnect-to-BP2.zip

BTW: A hearty thank you to the Nordic folk who made nRFconnect... fabulous...

RE: Can't find services using ble_db_discovery_start()

Sigurd — Sun, 04 May 2025 18:21:56 GMT

Hi!

Could you capture a trace where you use a different central, e.g. a phone , or another DK with the nRF Connect for Desktop BLE app as the central? Then we can compare the sniffer traces to a working and a non-working example.

RE: Can't find services using ble_db_discovery_start()

Randy Lee — Wed, 30 Apr 2025 16:21:23 GMT

OK, I think I figured out how to track connections and whatnot... So what I did here was to track my target instead of the central to see what it's doing. Looks like it's asking for this 0001 and getting it rejected. See starting at line 7563.

So that has me wondering about this whole, how you decide what you're looking after thing... I'm guessing I have this set up incorrectly some how... What's the sequence of calls with what values to get this looking correctly?

Also, I'm wanting to lok at a couple of services here.. Should I just add the UUIDs of things I'm looking for?

Looking at the particular record where it's asking about the UUID, it has the composite UUID correct as far as I can tell unless it needs to be asking in big endian order.

devzone.nordicsemi.com/.../BP2-connction-db-looking-for-services.zip

RE: Can't find services using ble_db_discovery_start()

Sigurd — Wed, 30 Apr 2025 11:19:23 GMT

Hi!

Right now the trace only have advertising data.

Make sure to select the device you want to follow into a connection here:

then you should be able to see the packets for the connection as well.

RE: Can't find services using ble_db_discovery_start()

Randy Lee — Mon, 28 Apr 2025 20:50:48 GMT

OK, I got wireshark running using a nRF52840DK board. [I programmed it using the embedded jLink (the end USB plug) but I had to run the side plug to get it show up on wireshark correctly -- don't recall seeing that step anywhere]

Included here is that full log (which apparently includes all kinds of irrelevant stuff but I'm hardly an expert in using wireshark so I figure more is better than the wrong things...

The top highlighted address (e8:b9:71;76:79:29) is the client here and the bottom highlighted address (c9:8b:ea:a8:49:eb) is the peripheral that I'm connecting to and attempting to index...

devzone.nordicsemi.com/.../cant-find-services.zip

RE: Can't find services using ble_db_discovery_start()

Randy Lee — Tue, 22 Apr 2025 13:30:52 GMT

oh yes... Using a nRFconnect mobile device, I can connect to the target, see all the services, and get notifications of the one I'm after just fine.. Looks and behaves completely normal in interaction there.

So I'm thinking that I'm somehow not doing it right on the client end.

RE: Can't find services using ble_db_discovery_start()

Sigurd — Tue, 22 Apr 2025 13:02:21 GMT

[quote user="Randy Lee"]Not just now, but I'll try to work to get that running on my machine... it'll take a few days tho I think. [/quote]

Ok.

Are you able to discover the service using e.g, nRF Connect for Mobile ?

https://www.nordicsemi.com/Products/Development-tools/nRF-Connect-for-mobile

RE: Can't find services using ble_db_discovery_start()

Randy Lee — Tue, 22 Apr 2025 12:41:39 GMT

Not just now, but I'll try to work to get that running on my machine... it'll take a few days tho I think.

RE: Can't find services using ble_db_discovery_start()

Sigurd — Tue, 22 Apr 2025 11:51:49 GMT

Hi!

Are you able to capture a sniffer log of this ? https://www.nordicsemi.com/Products/Development-tools/nRF-Sniffer-for-Bluetooth-LE