How to use nrf54L15-dk with external host through hci uart application

[Abhinav152]

Hi, 

I am trying to build an application using the nrf54L15-dk board and want to use the board as a controller. I run the application on the external host but got an error as controller responsive. Can you provide the details steps so that board can be use with external host.

[Simonr]

Hi

Can you share some details on what sample project you're based your own project on here? And what UART instance and pins on the nRF54L15 are you using for HCI UART here? Please note that some of the pins are not available on the DK, and the different instances have a set amount of pins that can be used (specific ports).

Is either of these the sample you've based your project on by chance?

• Bluetooth: HCI UART
• HCI UART

Best regards,

Simon

[Abhinav152]

Hi,
Thanks for your response.
i am using the hci_uart application of Zephyr.

Following is the nrf54l15dk_nrf54l15_cpuapp.overlay file i am using

&uart20 {

current-speed = <115200>;

hw-flow-control;

status = "okay";

};

&uart20_default {

group1 {

psels = <NRF_PSEL(UART_TX, 1, 11)>,

<NRF_PSEL(UART_RTS, 0, 2)>;

};

group2 {

psels = <NRF_PSEL(UART_RX, 1, 10)>,

<NRF_PSEL(UART_CTS, 0, 3)>;

bias-pull-up;

};

};



Also, i want to use a channel-sounding feature hence please suggest the necessary flag to enable this. Following is proj.conf file

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_ACL_RX_SIZE=255

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_CTLR_ADV_EXT=y

CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=512

[ivan iushkov]

https://docs.nordicsemi.com/bundle/ncs-latest/page/nrfxlib/softdevice_controller/doc/channel_sounding.html#developing_with_cs suggests the following KConfig option to enable Channel Sounding:

CONFIG_BT_CTLR_CHANNEL_SOUNDING=y

[Abhinav152]

Hi ivan iushkov,

I just tried these flags but giving a warning as the flag can't be enabled. Required BT_CTLR_CHANNEL_SOUNDING_SUPPORT  is warning. If i tried to allow this flag to but got an error that the flag is not user configurable  

[Simonr]

Hi

Regarding your pin selections for UART here, the UART20 instance should only be used with GPIO port P1, so please use pins on P1 for RTS and CTS as well. Do you have some more details on what error exactly you're seeing when the controller shows as unresponsive? Another important note is that by default P1.10 on the DK. So this pin by default is likely acting as an LED that is active high. You might need to change what pin LED1 uses to avoid conflicts on your end.

Best regards,

Simon