samples/bluetooth/central/src/main.c

/* main.c - Application main entry point */

/*
 * Copyright (c) 2015-2016 Intel Corporation
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <zephyr/types.h>
#include <stddef.h>
#include <errno.h>
#include <zephyr.h>
#include <misc/printk.h>

#include <bluetooth/bluetooth.h>
#include <bluetooth/hci.h>
#include <bluetooth/conn.h>
#include <bluetooth/uuid.h>
#include <bluetooth/gatt.h>
#include <misc/byteorder.h>

static struct bt_conn *default_conn;

static void device_found(const bt_addr_le_t *addr, s8_t rssi, u8_t type,
			 struct net_buf_simple *ad)
{
	char addr_str[BT_ADDR_LE_STR_LEN];

	if (default_conn) {
		return;
	}

	/* We're only interested in connectable events */
	if (type != BT_LE_ADV_IND && type != BT_LE_ADV_DIRECT_IND) {
		return;
	}

	bt_addr_le_to_str(addr, addr_str, sizeof(addr_str));
	printk("Device found: %s (RSSI %d)\n", addr_str, rssi);

	/* connect only to devices in close proximity */
	if (rssi < -70) {
		return;
	}

	if (bt_le_scan_stop()) {
		return;
	}

	default_conn = bt_conn_create_le(addr, BT_LE_CONN_PARAM_DEFAULT);
}

static void connected(struct bt_conn *conn, u8_t err)
{
	char addr[BT_ADDR_LE_STR_LEN];

	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));

	if (err) {
		printk("Failed to connect to %s (%u)\n", addr, err);
		return;
	}

	if (conn != default_conn) {
		return;
	}

	printk("Connected: %s\n", addr);

	bt_conn_disconnect(conn, BT_HCI_ERR_REMOTE_USER_TERM_CONN);
}

static void disconnected(struct bt_conn *conn, u8_t reason)
{
	char addr[BT_ADDR_LE_STR_LEN];
	int err;

	if (conn != default_conn) {
		return;
	}

	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));

	printk("Disconnected: %s (reason %u)\n", addr, reason);

	bt_conn_unref(default_conn);
	default_conn = NULL;

	/* This demo doesn't require active scan */
	err = bt_le_scan_start(BT_LE_SCAN_PASSIVE, device_found);
	if (err) {
		printk("Scanning failed to start (err %d)\n", err);
	}
}

static struct bt_conn_cb conn_callbacks = {
		.connected = connected,
		.disconnected = disconnected,
};

void main(void)
{
	int err;

	err = bt_enable(NULL);
	if (err) {
		printk("Bluetooth init failed (err %d)\n", err);
		return;
	}

	printk("Bluetooth initialized\n");

	bt_conn_cb_register(&conn_callbacks);

	err = bt_le_scan_start(BT_LE_SCAN_ACTIVE, device_found);
	if (err) {
		printk("Scanning failed to start (err %d)\n", err);
		return;
	}

	printk("Scanning successfully started\n");
}