Extended Advertising with FEM/MPSL

RE: Extended Advertising with FEM/MPSL

Einar Thorsrud — Tue, 04 Feb 2025 13:36:27 GMT

Hi,

I am glad to hear it is working. Regarding the error, it is printed here in conn.c. This is only calle dwith CONFIG_BT_AUTO_PHY_UPDATE, and if that is not something you need or want (it is handled explicitly by the application or the peer,), you can set CONFIG_BT_AUTO_PHY_UPDATE=n in your project configuration. That said, following this further down I think it comes from here, but it could be interesting to confirm that with a debugger, and see what else you can find that way if you want CONFIG_BT_AUTO_PHY_UPDATE enabled.

RE: Extended Advertising with FEM/MPSL

LukeC — Tue, 04 Feb 2025 05:49:39 GMT

I only enabled the SW_SPLIT because I thought I needed this to enable two advertising sets, one for standard 1mbps phy and one for coded phy. Per the warning below:

warning: BT_CTLR_ADV_AUX_SET (defined at subsys/bluetooth/controller/Kconfig.ll_sw_split:319) was
assigned the value '2' but got the value ''. Check these unsatisfied dependencies: BT_LL_SW_SPLIT
(=n). See http://docs.zephyrproject.org/latest/kconfig.html#CONFIG_BT_CTLR_ADV_AUX_SET and/or look
up BT_CTLR_ADV_AUX_SET in the menuconfig/guiconfig interface. The Application Development Primer,
Setting Configuration Values, and Kconfig - Tips and Best Practices sections of the manual might be
helpful too.

Perhaps it will work just with the following settings and not need the SW_SPLIT?

CONFIG_BT_EXT_ADV_MAX_ADV_SET=2
CONFIG_BT_EXT_ADV=y
CONFIG_BT_CTLR_PHY_CODED=y

Update:

Removing the SW_SPLIT and CONFIG_BT_CTLR_ADV_AUX_SET seems to still allow both standard and coded phy advertising on two different advertising sets. I can find the device scanning on LE 1M and coded phy.

I do get this odd error message that setting the phy fails "Failed LE Set PHY (-5)". This may not be a problem because the phy update reports the connection is using the coded phy. It might be coming from

bt_conn_le_phy_update call. I would like to request the coded phy even if the connection was initiated on the 1Mbps phy.

Connection (1) - Initial Tx Power = 8
[00:00:27.780,364] <inf> ble_periph: Gap connected peripheral id: 0, handle: 1.
[00:00:27.780,975] <wrn> bt_hci_core: opcode 0x2032 status 0x3a
[00:00:27.780,975] <err> bt_hci_core: Failed LE Set PHY (-5)
[00:00:28.023,986] <inf> main: Conn 0 RSSI is -30 db.
[00:00:28.697,235] <inf> ble_main: Phy Updated to RX=4 TX=4
[00:00:29.024,353] <inf> main: Conn 0 RSSI is -32 db.
Updated MTU: TX: 517 RX: 498 bytes
[00:00:30.024,810] <inf> main: Conn 0 RSSI is -35 db.
[00:00:31.025,177] <inf> main: Conn 0 RSSI is -35 db.

RE: Extended Advertising with FEM/MPSL

Einar Thorsrud — Mon, 03 Feb 2025 13:46:24 GMT

Hi,

[quote user=""](2.9 seems to give an HCI build error , undefined reference to `__device_dts_ord_135',[/quote]

It would be interesting to solve this issue instead of using an old SDK, see here.

[quote user=""]when enabled CONFIG_BT_LL_SW_SPLIT,[/quote]

This config is used to enable the Zephyr BLE link layer, and that is not supported.

[quote user=""]If i disable CONFIG_MPSL_FEM, and CONFIG_MPSL, the extended advertising works well.[/quote]

If you are trying to use CONFIG_BT_LL_SW_SPLIT that will not work in combination with the MPSL, the MPSL only works with the SoftDevice Controller (which is the one you should use).

[quote user=""]Is there a way to allow both Coded Phy advertising to work with FEM? Thanks![/quote]

Yes, that should not be a problem. But make sure you do not change to Zephyr LL. See Enabling support for front-end modules using Simple GPIO interface.