Impossible to scan extended advertising data when the data size is bigger than 31 Bytes.

[j_delsol_catie]

Hello,

I need to scan the advertising data of my peripheral wich advertise with extended advertsing and LE coded PHY.

I use zephyr 3.7, and I work if I use the BLE controller from Zephyr but that doesn't work with SoftDevice controller... I'm limited to 31 Bytes.

If my advertising data is smaller than 32 Bytes, it works.

here my scan config.

struct bt_le_scan_param scan_param = {

.type = BT_LE_SCAN_TYPE_PASSIVE,

.options = BT_LE_SCAN_OPT_CODED,

.interval = BT_GAP_SCAN_FAST_INTERVAL,

.window = BT_GAP_SCAN_FAST_WINDOW,

};

my prj.conf for my cpunet firmware:

CONFIG_HEAP_MEM_POOL_SIZE=8192

CONFIG_MAIN_STACK_SIZE=2048

CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=2048

CONFIG_MBOX=y

CONFIG_IPC_SERVICE=y

CONFIG_BT=y

CONFIG_BT_HCI_RAW=y

CONFIG_BT_CTLR_ASSERT_HANDLER=y

CONFIG_BT_MAX_CONN=16

# Enable and adjust the below value as necessary

# CONFIG_BT_BUF_EVT_RX_COUNT=16

# CONFIG_BT_BUF_EVT_RX_SIZE=255

# CONFIG_BT_BUF_ACL_RX_SIZE=255

# CONFIG_BT_BUF_ACL_TX_SIZE=251

# CONFIG_BT_BUF_CMD_TX_SIZE=255

CONFIG_BT_EXT_ADV=y

CONFIG_BT_CTLR_ADV_EXT=y

CONFIG_BT_CTLR_PHY_CODED=y

CONFIG_BT_CTLR_ADV_DATA_LEN_MAX=250

CONFIG_BT_CTLR_SCAN_DATA_LEN_MAX=255

CONFIG_ASSERT=y

CONFIG_DEBUG_INFO=y

CONFIG_EXCEPTION_STACK_TRACE=y

CONFIG_IPC_RADIO_BT=y

CONFIG_IPC_RADIO_BT_HCI_IPC=y

and my prj.conf for my cpuapp:

CONFIG_LOG=y

CONFIG_DK_LIBRARY=y

CONFIG_NCS_SAMPLES_DEFAULTS=y

CONFIG_HEAP_MEM_POOL_SIZE=4096

CONFIG_BT=y

CONFIG_BT_CENTRAL=y

CONFIG_BT_GATT_CLIENT=n

CONFIG_BT_HRS_CLIENT=n

CONFIG_BT_GATT_DM=n

CONFIG_BT_SCAN=y

CONFIG_BT_OBSERVER=y

CONFIG_BT_SCAN_FILTER_ENABLE=y

# CONFIG_BT_SCAN_UUID_CNT=1

CONFIG_BT_SCAN_MANUFACTURER_DATA_CNT=3

CONFIG_BT_SCAN_MANUFACTURER_DATA_MAX_LEN=255

CONFIG_BT_EXT_ADV=y

CONFIG_BT_USER_PHY_UPDATE=y

Do you have an idea ?

Thanks in advance.

Best regards,

julien

[dejans]

Hi Julien,

Are you limited to 31 bytes of advertising data when using SoftDevice Controller but not limited to 31 bytes if you use Zephyr controller?

Best regards,
Dejan

[j_delsol_catie]

Hi Dejan,

I'm limited only on the scanner device.
My advertiser device send 235 Bytes on the advertising data (I use MANUFACTURER_SPECIFIC_DATA type) with extended adv but my scanner device don't see them... however if I reduce, for example, the advertising data size to 31 Bytes, I see them with my scanner device.

If I use the Zephyr BLE controller for my advertiser device, I can't increase the adv_data size more than 191 Bytes (it's limited by the Zephyr BLE controller). So I use the SoftDevice controller.


Regards,

Julien

[j_delsol_catie]

Finally I can see 191 Bytes maximum on my scanner device but I have to configure the advertiser to send only 191 Bytes max else it doesn't work.

However, on my smartphone, I can see correctly the totality of adv_data (when my advertiser send  more than 191 Bytes).

Regards,

Julien

[j_delsol_catie]

[dejans]

Hi Julien,

Does scanning with both controllers work fine up until advertisement data length of 191 bytes? 

Does the problem occur only when scanning for advertisement data of the length 192 bytes and more in case when SoftDevice Controller is used?

Best regards,
Dejan