Bluetooth master-slave start scan failed

RE: Bluetooth master-slave start scan failed

Edvin — Mon, 13 Mar 2023 13:37:28 GMT

Hello,

Andreas is out of office, so I will look into this ticket.

Is this something that I would be able to reproduce on the nRF52840 DK?

[quote user="Magdalena"]2. Use Nordic Controller: Failed to start advertiser[/quote]

What value does the advertising start function return?

Best regards,

Edvin

RE: Bluetooth master-slave start scan failed

Harvey Zheng — Wed, 08 Mar 2023 01:54:14 GMT

[quote user="AHaug"]Scan timeout = 2
CONFIG_BT_EXT_ADV_MAX_ADV_SET=2
CONFIG_BT_MAX_CONN=3[/quote]

I have tested it in two situations and it does not work.

1. Use Zephyr Controller: Scanning failed to start

2. Use Nordic Controller: Failed to start advertiser

[quote user="AHaug"]It looks like that there could be an implied dependency that increases BT_MAX_CONN to 3 if BT_EXT_ADV_MAX_ADV_SET is set to 3 which might be why the scanning starts with the last configuration.[/quote]

When CONFIG_BT_EXT_ADV_MAX_ADV_SET=3, after compilation, CONFIG_BT_MAX_CONN is not increased to 3

[quote user="AHaug"]Having both Central and peripheral support = 2 connections. If you add scanning this will require BT_MAX_CONN = 3 to run.[/quote]

Scan timeout = 0
CONFIG_BT_EXT_ADV_MAX_ADV_SET=2
CONFIG_BT_MAX_CONN=2

What I can't understand is that the above configuration works fine when the scan timeout is 0. According to you, doesn't it need to set CONFIG_BT_EXT_ADV_MAX_ADV_SET or CONFIG_BT_MAX_CONN to 3?

RE: Bluetooth master-slave start scan failed

AHaug — Tue, 07 Mar 2023 14:08:58 GMT

It looks like this is correct.

From what I have seen in other similar cases and discussion, the fix is to either increase the CONFIG_BT_MAX_CONN=3 or disable BT_CENTRAL, which should give you two advertising sets and one scan. When you set the number of slave connections to 2, you will need to disable the central role support or to increase the maximum allowed BT_CONN. Having both Central and peripheral support = 2 connections. If you add scanning this will require BT_MAX_CONN = 3 to run.

Could you try with the following configuration and report back to me what you see?

Scan timeout = 2
CONFIG_BT_EXT_ADV_MAX_ADV_SET=2
CONFIG_BT_MAX_CONN=3

Kind regards,
Andreas

RE: Bluetooth master-slave start scan failed

Harvey Zheng — Tue, 07 Mar 2023 00:59:38 GMT

1. These configurations can run:

Scan timeout = 0
CONFIG_BT_EXT_ADV_MAX_ADV_SET=2
CONFIG_BT_MAX_CONN=2

2. These configurations cannot run:

Scan timeout = 2
CONFIG_BT_EXT_ADV_MAX_ADV_SET=2
CONFIG_BT_MAX_CONN=2

3. These configurations can run:

Scan timeout = 2
CONFIG_BT_EXT_ADV_MAX_ADV_SET=3
CONFIG_BT_MAX_CONN=2

RE: Bluetooth master-slave start scan failed

Harvey Zheng — Tue, 07 Mar 2023 00:54:29 GMT

[quote user="AHaug"]

Just to clarify:

Scan timeout = 0
CONFIG_BT_EXT_ADV_MAX_ADV_SET=2
CONFIG_BT_MAX_CONN=2
Scan timeout = 2
CONFIG_BT_EXT_ADV_MAX_ADV_SET=2
CONFIG_BT_MAX_CONN=2

These configurations does not work?

Scan timeout = 2
CONFIG_BT_EXT_ADV_MAX_ADV_SET=3
CONFIG_BT_MAX_CONN=2

[/quote]

Hi,

Yes, my samp do run like this.

RE: Bluetooth master-slave start scan failed

AHaug — Mon, 06 Mar 2023 14:14:24 GMT

Hi,

Just to clarify:

Scan timeout = 0
CONFIG_BT_EXT_ADV_MAX_ADV_SET=2
CONFIG_BT_MAX_CONN=2
Scan timeout = 2
CONFIG_BT_EXT_ADV_MAX_ADV_SET=2
CONFIG_BT_MAX_CONN=2

These configurations does not work?

Scan timeout = 2
CONFIG_BT_EXT_ADV_MAX_ADV_SET=3
CONFIG_BT_MAX_CONN=2

This configuration does work?

It looks like that there could be an implied dependency that increases BT_MAX_CONN to 3 if BT_EXT_ADV_MAX_ADV_SET is set to 3 which might be why the scanning starts with the last configuration.

Let me know about the clarification question above, and I'll have a closer look

Kind regards,
Andreas