NCS scan_adv example doesn't work on nrf52811

[Sam Lin]

Hi All,

I tried NCS example scan_adv to test nrf52811 however it's stopped on bt_enable()

the log as:

[16:36:13:020] *** Booting Zephyr OS build v2.4.0-ncs1-1699-gcdc4c217fbd0 ***␍␊

[16:36:13:025] Starting Scanner/Advertiser Demo␍␊

[16:36:13:028] Bluetooth init failed (err -35)␍␊

[16:36:13:031] [00:00:00.008,666] <0x1b>[0m<inf> sdc_hci_driver: SoftDevice Controller build revision: ␍␊

[16:36:13:039] d4 43 b5 cf 63 22 e9 d4 ed 8a 24 d0 4c a1 f7 b1 |.C..c".. ..$.L...␍␊

[16:36:13:048] a4 26 85 75 |.&.u <0x1b>[0m␍␊

[16:36:13:058] [00:00:00.008,697] <0x1b>[1;31m<err> bt_hci_core: HCI driver open failed (-35)<0x1b>[0m␍␊

I verified nrf52840 it's working.

Is there any issue to run scan_adv on nrf52811 ?

BR,

Sam

[Hung Bui]

Hi Sam, 

The reason you received error -35 (ENOTSUP) is that by default when you use nRF52811 chip, it will use the S112 controller stack by default. 

The S112 stack doesn't have data length extension support. 
You can have a look here.

I tested adding the following configuration into peripheral_lbs's prj.conf:

CONFIG_BT_DATA_LEN_UPDATE=n

And it worked with nRF52840dk_nRF52811 board. 

[Sam Lin]

Hi Hung,

I want to use nRF52811 with S140 (for coded phy scanner) what should I do ?

BR,

Sam

[Hung Bui]

Hi Sam, 
You can force the stack to use S140 by using this config:

CONFIG_SOFTDEVICE_CONTROLLER_S140=y

Please be aware that the flash and RAM size of NRF52811 is quite limited, you may need to build optimization and maybe turn off debugging info/logging.

[Sam Lin]

Hi Hung,

I can use S140 now.

For size optimization, if I don't use GATT (I only use ADVERTISER and OBSERVER) is there any option to trim down stack size ?

BR,

Sam

[Hung Bui]

Hi Sam, 

You can have a look here: https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/app_memory.html?highlight=size%20optimize#bluetooth

You should also use CONFIG_BT_CONN=n to remove any GATT server or connection code.