RE: Device unable advertise after disconnecting from host

cscase — Fri, 20 Oct 2023 19:41:48 GMT

Thank you, Vidar.

Your response was very helpful and I think helped me get to a resolution.

I believe the idea you presented in your item #1 may have hit close to the truth. You said:

"My idea with this is that there may be an internal state flag that is not cleared by the time advertising start is called making the stack try to configure a new advertisement set."

This got me thinking and looking. I found that in addition to the callback I mentioned above, there was other code calling for advertising to restart following a disconnect event. Maybe these two pieces of code, both calling for advertising restart in short succession, sometimes aligned in a way that created that bad state? At any rate, once I had removed that other code, this problem SEEMS to have gone away. I'm going to do more extensive testing to verify, but it certainly seems to be fixed.

Thanks again! I'm very grateful for your help on this.

Scott

RE: Device unable advertise after disconnecting from host

Vidar Berg — Fri, 20 Oct 2023 14:06:26 GMT

Hi Scott,

I don't have any good ideas as to why the advertiser fails to start other than that it sounds like it may be timing related. Logging over RTT could be an alternative to using UART for figuring out what the error code is. However, there is a chance that RTT logging may mask the problem too considering it's using the same logging infrastructure.

To troubleshoot this, I recommend you try one of the following steps:

1. Increase the max. number of advertisement sets supported in the hci_rpsmg sample (BT controller) running on the network core through the CONFIG_BT_CTLR_ADV_SET symbol. It should be '1' by default. My idea with this is that there may be an internal state flag that is not cleared by the time advertising start is called making the stack try to configure a new advertisement set.

2. Increase the max. number of supported BLE connections in the app with CONFIG_BT_MAX_CONN assuming the current limit is 1.

3. Place a breakpoint that will be hit if bt_le_ext_adv_start() returns with an error. Then use the debugger to check the error code.

Kconfig settings to enable RTT logging

CONFIG_LOG=y
CONFIG_USE_SEGGER_RTT=y
CONFIG_LOG_BACKEND_RTT=y
CONFIG_LOG_BACKEND_UART=n

I would also recommend upgrading to a more recent SDK version if possible. While I can't guarantee it will resolve the specific issue you're encountering, there have been numerous improvements and bug fixes since v1.7.0.

Best regards,

Vidar