hrs example with btuuid128

RE: hrs example with btuuid128

Hung Bui — Thu, 09 Mar 2023 08:18:06 GMT

Hi Boris,
I'm sorry for late reply. You are right on the fact that the callback will be called for each element found in the advertising data. The BT_DATA_UUID16_ALL and BT_DATA_UUID16_SOME are considered a element but as the name suggest (all or some), they may contain multiple UUIDs inside.

This is why we need to go through it to find if the HRS UUID is inside.

RE: hrs example with btuuid128

boris bergman1 — Tue, 07 Mar 2023 11:09:42 GMT

Sorry I made an mistake, the discover_func callback needs an 16bit uuid for BT_UUID_GATT_CCC. I changed that now it works. Resides one more question:

Why does eir_found loops through the data in the hr_central example. bt_data_parse function explanations says: "Callback function which will be called for each element that's found in the data. The callback should return true to continue parsing, or false to stop parsing.".

RE: hrs example with btuuid128

Hung Bui — Tue, 07 Mar 2023 08:58:30 GMT

Hi Boris,

If you don't want to use Nordic library, you still can have a look at the gatt_dm.c and see how we used

Zephyr's bt_gatt_discover() library inside that.

From what I can see it's not much different from the central_hr example. What you need to check is to see when discover_func() returned if it managed to find the NUS service or not (please try to test your application using NUS UUID first). If not then you would need to check what's the difference in central_nus example that it managed to discover the service. Make sure you declare the exact same UUID on both the central and peripheral.

RE: hrs example with btuuid128

boris bergman1 — Mon, 06 Mar 2023 13:26:15 GMT

I knew you would come up with nordic uart, but that example uses a lot of nordic libraries, I just want to use a custom uuid in the zephyr example. discover_func is called, once. I'll try the sniffer.

RE: hrs example with btuuid128

Hung Bui — Mon, 06 Mar 2023 11:52:47 GMT

Hi Boris,

I would suggest to use a nRF Sniffer to track what happen over the air so we can have better understanding on what the central and peripheral is doing.

Have you checked if the central managed to do service discovery and the discover_func() callback is called ? And how many times it has been called ?

I would suggest to have a look into our central_uart (and peripheral_uart) sample. The examples show how to use a 128 bits UUID proprietary service/characteristic.