btstack/test/le_audio/README.md

These samples are meant to be used with the PTS Dongel or an equivalent setup like the one described in here using a nrf5340dk.

nrf5340dk as HCI dongle

for this a working Zephyr build environment is required, where the setup of Zephyr is beyond the scope of this document.

The nrf5340 is a dual core SOC for which the network core handles the low level radio control and the application core handles the actual application. So to make a working dongle the network core and the application core need to be programmed.

network core / Packetcraft LL

for nrf5340 the latest netcore firmware is located at sdk-nrf to program it:

nrfjprog --program ble5-ctr-rpmsg_<version number>.hex --chiperase --coprocessor CP_NETWORK -r

application core

the hci_uart sample is used here over USB CDC build using:

west build -b nrf5340dk_nrf5340_cpuapp -- -DDTC_OVERLAY_FILE=usb.overlay -DOVERLAY_CONFIG=overlay-usb.conf

with usb.overlay specifying to use USB CDC instead of a physical UART

/*
 * Copyright (c) 2021 Nordic Semiconductor ASA
 *
 * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
 */

/ {
	chosen {
		zephyr,bt-c2h-uart = &cdc_acm_uart0;
	};
};

&zephyr_udc0 {
	cdc_acm_uart0: cdc_acm_uart0 {
		compatible = "zephyr,cdc-acm-uart";
	};
};

and overlay-usb.conf to enable USB

CONFIG_USB_DEVICE_STACK=y
CONFIG_USB_DEVICE_PRODUCT="Zephyr HCI UART sample"
CONFIG_USB_CDC_ACM=y
CONFIG_USB_DEVICE_INITIALIZE_AT_BOOT=n