Resume advertising is not working

RE: Resume advertising is not working

Hieu — Mon, 07 Nov 2022 15:54:34 GMT

Hi Thomas,

I will follow up with your colleague (and you?) in that ticket.

For this current case, I have suggested my answers for regular BLE and LE Audio as the answers. If you agree, please verify it and the question will be automatically closed. Or I can close it manually in a few days, as I believe we are at a good place to stop as far as the original question is concerned.

Best regards,

Hieu.

RE: Resume advertising is not working

ThomasW — Mon, 07 Nov 2022 07:46:56 GMT

Hi,

One of my colleague opened a private ticket: devzone.nordicsemi.com/.../298027

Could you have a look ?

Thanks

RE: Resume advertising is not working

Hieu — Thu, 03 Nov 2022 18:53:18 GMT

Hi ThomasW,

It seems that, at least as of NCS 2.1.1 multiple centrals and LE Audio is just not possible.

Could you please let us know your use case? While unlikely, perhaps we can recommend a workaround. If such sharing is sensitive, we could provide support in a private ticket.

Best regards,

Hieu

RE: Resume advertising is not working

ThomasW — Wed, 02 Nov 2022 12:39:08 GMT

Hi,

The product I'm developing needs this feature (BLE Audio and multiple centrals connection on its GATT server). How can we solve this issue ?

Thanks

RE: Resume advertising is not working

Hieu — Wed, 02 Nov 2022 10:09:26 GMT

Hi ThomasW,

The CONFIG_BT_CTLR_SDC_PERIPHERAL_COUNT we talked about is to configure the SoftDevice Controller in normal BLE applications.

The Audio application uses a different BLE Controller, the LE Audio Controller Subsystem, so the above configuration does not take effect.
This controller, as included in the precompiled binary, unfortunately can only support as followed:
- As central, connects to two peripherals
- As peripheral, connects to one central

Best regards,

Hieu

RE: Resume advertising is not working

ThomasW — Tue, 01 Nov 2022 16:16:50 GMT

Hi,

Thanks for this answer, I'll try it and check it's working.

Using this sample, I was able to reproduce an issue I have with the firmware provided by the audio samples, so it's not in the real condition.

Giving your answer and the fact that I don't have the source code for the binary provided for the audio application (https://github.com/nrfconnect/sdk-nrf/blob/v2.1.0/applications/nrf5340_audio/bin/ble5-ctr-rpmsg_3303.hex), can you check the value of "CONFIG_BT_CTLR_SDC_PERIPHERAL_COUNT" for this firmware ?

Thank you.

RE: Resume advertising is not working

Hieu — Mon, 31 Oct 2022 15:49:57 GMT

Hi ThomasW,

I think I found the problem.

In the nRF5340, you also need to configure the NetCore. Therefore, you need to create/update <Project Root>/child_image/hci_rpmsg.conf as followed:

CONFIG_BT_CTLR_SDC_PERIPHERAL_COUNT=<Your maximum number of connections as peripheral>

Remember to perform a pristine build so that the build system picks up your new .conf file.

Regarding the LED, please forget about it. Even though the documentation says it blinks while the device is advertising, it just blinks forever.
I will have to check with SDK/documentation teams, but that is irrelevant to our discussion here.

Best regard,

Hieu

RE: Resume advertising is not working

ThomasW — Thu, 27 Oct 2022 14:23:26 GMT

Hi,

I don't have a board to check the LED, sorry.

The matter is pretty urgent, I was hoping to have an answer before the end of next week, but I'll try to find a workaround if it's not possible. Can you let me know please ?

Thanks.

RE: Resume advertising is not working

Hieu — Mon, 24 Oct 2022 13:43:26 GMT

Hi ThomasW,

Just want to let you know that today I have reproduced your observation on my nRF5340 DK, both with your files and with simply changing CONFIG_BT_MAX_CONN to something >1.
I would like to believe I didn't see this last week, but it is not like I recorded a video or anything... On the bright side, we are now on the same page and that is better.

It is worth noting that the LED which indicate that the nRF5340 is advertising is indeed blinking, just no advertisement comes out. Do you see the same behavior on your end?

By the way, with the same project files I don't see the problem on the nRF52 DK.

That's all I have for today. But given what I have seen so far, I am afraid I won't be back with an answer tomorrow, or even not in two days. If that is a problem, please let me know.

Best regards,

Hieu

RE: Resume advertising is not working

ThomasW — Sun, 23 Oct 2022 16:49:14 GMT

Hi,

You can find enclosed the desired files.

Since I use the sample, I don't change anything from the sample (except changing BT_MAX_CONN to 10 but I have the same behaviour if I don't change it)

devzone.nordicsemi.com/.../0044.peripheral_5F00_bms.zip devzone.nordicsemi.com/.../0458.Kconfig.zip

Let me know if you need anything else.

Thanks for the support.

RE: Resume advertising is not working

Hieu — Fri, 21 Oct 2022 13:23:30 GMT

Hi ThomasW,

Sorry, something comes up and I am a little flooded right now. I will come back with you next week, hopefully Monday, latest Tuesday.

Meanwhile, would you mind sharing me your final compiled Kconfig?
That, or could you please share your peripheral_bms folder as it is before building?
I understand that your setup is supposed to be the SDK untouched. However, as I have trouble reproducing the problem with an equivalent setup, that might help.

Finally, what advertising parameters were the bt_le_adv_start() called with?

Best regards,

Hieu

RE: Resume advertising is not working

ThomasW — Wed, 19 Oct 2022 15:46:38 GMT

Hi,

I tried again the `bluetooth/peripheral_bms` sample on sdk-nrf repository using tag v2.1.0, and I have the same behavior: Advertising does not restart.

This is exactly the steps I followed:

- west init -m github.com/.../sdk-nrf --mr v2.1.0

- west update

- cd nrf/samples/bluetooth/peripheral_bms

- west build -d build -b nrf5340dk_nrf5340_cpuapp .

- nrfjprog -e

- west flash -d build

- I use `nRF Connect` on my phone, I run a scan and then I connect to `Nordic_BMS`

- I use a SECOND phone, I run a scan, and I can't see any devices `Nordic_BMS`

- If I disconnect from my first phone, I can see the `Nordic_BMS` device advertising on my SECOND phone.

No reason to use a branch, it's a mistake, So like you suggested I switch on a tag instead.

RE: Resume advertising is not working

Hieu — Wed, 19 Oct 2022 15:13:31 GMT

Hi ThomasW,

I just run the samples and look at their main.c codes; and it seems that you are right that advertising is automatically resume when a connection is established, and the device is capable for more connections.

I have updated my previous reply in order to prevent spreading of misinformation. I'm sorry about that. It was wrong of me to assume my knowledge from nRF5 SDK holds true in NCS...

In any cases, I also observed that advertisement starts again on its own just fine in both the GATT DM and BMS samples.
I can connect a device to both my computer and my phone, and the only modification is CONFIG_BT_MAX_CONN=2 or 10.

Thus, I don't have an immediate idea why you were successful with Zephyr but not with NCS...
I have one idea, but I will need more time to check, so I will get back to you latest on Friday.

Meanwhile. this is unlikely but perhaps your NCS installation is corrupted?
How did you install it?
Your question mentioned you are working on a sdk-nrf branch. Is there a reason you don't work on a tagged release instead?

Best regards,

Hieu

RE: Resume advertising is not working

ThomasW — Wed, 19 Oct 2022 14:14:17 GMT

Hi,

I tried the `bluetooth/peripheral_bms` sample but once I connect to it (using my phone), it does not start advertising again.

FYI, it's my own instruction:

If I'm not mistaken, once a device is connected, bt_le_adv_resume will be automatically called by bt_hci_le_enh_conn_complete. But maybe setting CONFIG_BT_MAX_CONN > 1 is not enough. Maybe you can help me with that ?

I tried the `bluetooth/peripheral` sample on Zephyr (v3.2.0) with the same patch and advertising restarts again after a connection.

Do you know where the problem comes from ?

Thanks

RE: Resume advertising is not working

Hieu — Wed, 19 Oct 2022 13:02:08 GMT

Hello ThomasW,

I think there might be a misunderstanding here.

I can't replicate your patch action, but from the log I assume the only change is adding CONFIG_BT_MAX_CONN=10 to proj.conf, right?
This change only configures the sample setup to support 10 connections. It doesn't make the device advertise again.

Meanwhile, the sample you are working on, Peripheral GATT Device Manager (DM), is a sample designed to connect to one central, and therefore also doesn't have any code to advertise again.

If you wish to see advertisement starts again, you could check out the Peripheral Bond Management Service (BMS) sample, which is designed to connect two central devices out of the box.

If you wish to see the behavior in the Peripheral GATT DM sample, you need to write your own behavior. You could refer to the BMS sample for how to do so.

Out of curiosity, where did you find the instruction to patch the sample like you did?

Best regards,

Hieu

Edit: The information provided above regarding advertisement auto restart is incorrect and therefore I have editted it into strikethrough format.