samples/bluetooth/peripheral_nus/src/main.c

/*
 * Copyright (c) 2024 Croxel, Inc.
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <zephyr/kernel.h>
#include <zephyr/bluetooth/bluetooth.h>
#include <zephyr/bluetooth/services/nus.h>

#define DEVICE_NAME		CONFIG_BT_DEVICE_NAME
#define DEVICE_NAME_LEN		(sizeof(DEVICE_NAME) - 1)

static const struct bt_data ad[] = {
	BT_DATA_BYTES(BT_DATA_FLAGS, (BT_LE_AD_GENERAL | BT_LE_AD_NO_BREDR)),
	BT_DATA(BT_DATA_NAME_COMPLETE, DEVICE_NAME, DEVICE_NAME_LEN),
};

static const struct bt_data sd[] = {
	BT_DATA_BYTES(BT_DATA_UUID128_ALL, BT_UUID_NUS_SRV_VAL),
};

static void notif_enabled(bool enabled, void *ctx)
{
	ARG_UNUSED(ctx);

	printk("%s() - %s\n", __func__, (enabled ? "Enabled" : "Disabled"));
}

static void received(struct bt_conn *conn, const void *data, uint16_t len, void *ctx)
{
	char message[CONFIG_BT_L2CAP_TX_MTU + 1] = "";

	ARG_UNUSED(conn);
	ARG_UNUSED(ctx);

	memcpy(message, data, MIN(sizeof(message) - 1, len));
	printk("%s() - Len: %d, Message: %s\n", __func__, len, message);
}

struct bt_nus_cb nus_listener = {
	.notif_enabled = notif_enabled,
	.received = received,
};

int main(void)
{
	int err;

	printk("Sample - Bluetooth Peripheral NUS\n");

	err = bt_nus_cb_register(&nus_listener, NULL);
	if (err) {
		printk("Failed to register NUS callback: %d\n", err);
		return err;
	}

	err = bt_enable(NULL);
	if (err) {
		printk("Failed to enable bluetooth: %d\n", err);
		return err;
	}

	err = bt_le_adv_start(BT_LE_ADV_CONN_FAST_1, ad, ARRAY_SIZE(ad), sd, ARRAY_SIZE(sd));
	if (err) {
		printk("Failed to start advertising: %d\n", err);
		return err;
	}

	printk("Initialization complete\n");

	while (true) {
		const char *hello_world = "Hello World!\n";

		k_sleep(K_SECONDS(3));

		err = bt_nus_send(NULL, hello_world, strlen(hello_world));
		printk("Data send - Result: %d\n", err);

		if (err < 0 && (err != -EAGAIN) && (err != -ENOTCONN)) {
			return err;
		}
	}

	return 0;
}