How to configure hci_uart to scan and connect to Coded PHY (S=8) ADV_EXT_IND on nRF54L15-DK

[Lee1823]

Hello,

I am using the nRF54L15-DK development board running the official hci_uart example as the BLE controller. My own Linux system acts as the host using BlueZ to control the board.

I have found that with the default hci_uart example, it cannot scan ADV_EXT_IND packets with Coded PHY (S=8). Could you please advise what configurations I need to modify to successfully scan and connect to such devices?

Thank you!

[Ressa]

Hi,

Add the following configurations to your hci_uart project prj.conf:

CONFIG_BT_CTLR_PHY_CODED=y
CONFIG_BT_CTLR_ADV_EXT=y
CONFIG_BT_EXT_ADV=y

[Lee1823]

Hello,

I added the above configuration items as you suggested, but I still cannot scan BLE devices that send ADV_EXT_IND with Coded PHY (S=8) using bluetoothctl on my Linux host. Below is my modified configuration. Is there anything wrong with it? Thank you!

CONFIG_CONSOLE=n

CONFIG_STDOUT_CONSOLE=n

CONFIG_UART_CONSOLE=n

CONFIG_GPIO=y

CONFIG_SERIAL=y

CONFIG_UART_INTERRUPT_DRIVEN=y

CONFIG_BT=y

CONFIG_BT_HCI_RAW=y

CONFIG_BT_HCI_RAW_H4=y

CONFIG_BT_HCI_RAW_H4_ENABLE=y

CONFIG_BT_BUF_CMD_TX_SIZE=255

CONFIG_BT_BUF_EVT_DISCARDABLE_SIZE=255

CONFIG_BT_CTLR_ASSERT_HANDLER=y

CONFIG_BT_MAX_CONN=16

CONFIG_BT_CTLR_DTM_HCI=y

CONFIG_BT_DEVICE_NAME="nRF54-HCI"

CONFIG_BT_CTLR_PHY_CODED=y

CONFIG_BT_CTLR_PHY_2M=y

CONFIG_BT_CTLR_DATA_LENGTH_MAX=251

CONFIG_BT_BUF_ACL_RX_SIZE=255

CONFIG_BT_BUF_ACL_TX_SIZE=255

CONFIG_BT_CTLR_SDC_RX_PACKET_COUNT=10

CONFIG_BT_CTLR_SDC_TX_PACKET_COUNT=10

CONFIG_BT_L2CAP_TX_MTU=247

CONFIG_BT_GATT_AUTO_UPDATE_MTU=y

CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=512

# Scan Coded Adv

CONFIG_BT_CTLR_ADV_EXT=y

CONFIG_BT_EXT_ADV=y

[Ressa]

Hi,

Try to increase scan data length and RX buffers for extended adv packets (you might need to tune them a bit):

CONFIG_BT_CTLR_SCAN_DATA_LEN_MAX=191

Also if below line didn't help try to add below lines for RF buffers:

CONFIG_BT_EXT_SCAN_BUF_SIZE=1650
CONFIG_BT_BUF_EVT_RX_COUNT=16
CONFIG_BT_CTLR_RX_BUFFERS=9


(+) Cannot scan extended adv for packets > legacy length in zephyr - Nordic Q&A - Nordic DevZone - Nordic DevZone

[Lee1823]

Thank you for your help. I can now scan the extended advertisements of Coded normally as per your instructions.