blob: 74462a737d7b48466c7d232407e6b3f53137e0b9 [file] [log] [blame]
/** @file
* @brief Bluetooth Object Transfer Client Sample
*
* Copyright (c) 2022 Nordic Semiconductor ASA
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <errno.h>
#include <stddef.h>
#include <zephyr/bluetooth/bluetooth.h>
#include <zephyr/bluetooth/conn.h>
#include <zephyr/bluetooth/gatt.h>
#include <zephyr/bluetooth/hci.h>
#include <zephyr/bluetooth/services/ots.h>
#include <zephyr/bluetooth/uuid.h>
#include <zephyr/device.h>
#include <zephyr/drivers/gpio.h>
#include <zephyr/sys/byteorder.h>
#include <zephyr/sys/printk.h>
#include <zephyr/types.h>
#include <zephyr/kernel.h>
#define OBJ_MAX_SIZE 1024
/* Hardcoded here since definition is in internal header */
#define BT_GATT_OTS_OLCP_RES_OPERATION_FAILED 0x04
#define BT_GATT_OTS_OLCP_RES_OUT_OF_BONDS 0x05
static struct bt_ots_client otc;
static struct bt_ots_client_cb otc_cb;
static struct bt_gatt_discover_params discover_params;
static struct bt_gatt_subscribe_params *oacp_sub_params;
static struct bt_gatt_subscribe_params *olcp_sub_params;
static unsigned char obj_data_buf[OBJ_MAX_SIZE];
static uint32_t last_checksum;
static bool first_selected;
static void on_obj_selected(struct bt_ots_client *ots_inst, struct bt_conn *conn, int err);
static void on_obj_metadata_read(struct bt_ots_client *ots_inst, struct bt_conn *conn, int err,
uint8_t metadata_read);
static int on_obj_data_read(struct bt_ots_client *ots_inst, struct bt_conn *conn, uint32_t offset,
uint32_t len, uint8_t *data_p, bool is_complete);
static void start_scan(void);
static struct bt_uuid_16 uuid = BT_UUID_INIT_16(0);
static struct bt_conn *default_conn;
static atomic_t discovery_state;
enum OTS_SERVICE_DISCOVERY_STATE_BIT {
DISC_OTS_FEATURE,
DISC_OTS_NAME,
DISC_OTS_TYPE,
DISC_OTS_SIZE,
DISC_OTS_ID,
DISC_OTS_PROPERTIES,
DISC_OTS_ACTION_CP,
DISC_OTS_LIST_CP,
};
static void print_hex_number(const uint8_t *num, size_t len)
{
printk("0x");
for (size_t i = 0; i < len; i++) {
printk("%02x ", num[i]);
}
printk("\n");
}
/*
* Get buttons configuration from the devicetree sw0~sw3 alias. This is mandatory.
*/
#define SW0_NODE DT_ALIAS(sw0)
#define SW1_NODE DT_ALIAS(sw1)
#define SW2_NODE DT_ALIAS(sw2)
#define SW3_NODE DT_ALIAS(sw3)
#if !DT_NODE_HAS_STATUS(SW0_NODE, okay) || !DT_NODE_HAS_STATUS(SW1_NODE, okay) || \
!DT_NODE_HAS_STATUS(SW2_NODE, okay) || !DT_NODE_HAS_STATUS(SW3_NODE, okay)
#error "Unsupported board: This sample need 4 buttons to run"
#endif
static const struct gpio_dt_spec button0 = GPIO_DT_SPEC_GET_OR(SW0_NODE, gpios, {0});
static const struct gpio_dt_spec button1 = GPIO_DT_SPEC_GET_OR(SW1_NODE, gpios, {0});
static const struct gpio_dt_spec button2 = GPIO_DT_SPEC_GET_OR(SW2_NODE, gpios, {0});
static const struct gpio_dt_spec button3 = GPIO_DT_SPEC_GET_OR(SW3_NODE, gpios, {0});
#define BTN_COUNT 4
static const struct gpio_dt_spec btns[BTN_COUNT] = {button0, button1, button2, button3};
static struct gpio_callback button_cb_data;
struct otc_btn_work_info {
struct k_work_delayable work;
uint32_t pins;
} otc_btn_work;
struct otc_checksum_work_info {
struct k_work_delayable work;
off_t offset;
size_t len;
} otc_checksum_work;
static void otc_btn_work_fn(struct k_work *work)
{
struct k_work_delayable *dwork = k_work_delayable_from_work(work);
struct otc_btn_work_info *btn_work = CONTAINER_OF(dwork, struct otc_btn_work_info, work);
int err;
size_t size_to_write;
if (btn_work->pins == BIT(button0.pin)) {
if (!first_selected) {
err = bt_ots_client_select_id(&otc, default_conn, BT_OTS_OBJ_ID_MIN);
first_selected = true;
} else {
printk("select next\n");
err = bt_ots_client_select_next(&otc, default_conn);
}
if (err != 0) {
printk("Failed to select object (err %d)\n", err);
}
printk("Selecting object succeeded\n");
} else if (btn_work->pins == BIT(button1.pin)) {
printk("read OTS object meta\n");
err = bt_ots_client_read_object_metadata(&otc, default_conn,
BT_OTS_METADATA_REQ_ALL);
if (err != 0) {
printk("Failed to read object metadata (err %d)\n", err);
}
} else if (btn_work->pins == BIT(button2.pin)) {
if (BT_OTS_OBJ_GET_PROP_WRITE(otc.cur_object.props)) {
size_to_write = MIN(OBJ_MAX_SIZE, otc.cur_object.size.alloc);
(void)memset(obj_data_buf, 0, size_to_write);
printk("Going to write OTS object len %d\n", size_to_write);
for (uint32_t idx = 0; idx < size_to_write; idx++) {
obj_data_buf[idx] = UINT8_MAX - (idx % UINT8_MAX);
}
last_checksum = bt_ots_client_calc_checksum(obj_data_buf, size_to_write);
printk("Data sent checksum 0x%08x\n", last_checksum);
err = bt_ots_client_write_object_data(&otc, default_conn, obj_data_buf,
size_to_write, 0,
BT_OTS_OACP_WRITE_OP_MODE_NONE);
if (err != 0) {
printk("Failed to write object (err %d)\n", err);
}
} else {
printk("This OBJ does not support WRITE OP\n");
}
} else if (btn_work->pins == BIT(button3.pin)) {
if (BT_OTS_OBJ_GET_PROP_READ(otc.cur_object.props)) {
printk("read OTS object\n");
err = bt_ots_client_read_object_data(&otc, default_conn);
if (err != 0) {
printk("Failed to read object %d\n", err);
}
} else {
printk("This OBJ does not support READ OP\n");
}
}
}
static void otc_checksum_work_fn(struct k_work *work)
{
struct k_work_delayable *dwork = k_work_delayable_from_work(work);
struct otc_checksum_work_info *checksum_work =
CONTAINER_OF(dwork, struct otc_checksum_work_info, work);
int err;
err = bt_ots_client_get_object_checksum(&otc, default_conn, checksum_work->offset,
checksum_work->len);
if (err != 0) {
printk("bt_ots_client_get_object_checksum failed (%d)\n", err);
}
}
static void button_pressed(const struct device *dev, struct gpio_callback *cb, uint32_t pins)
{
otc_btn_work.pins = pins;
k_work_schedule(&otc_btn_work.work, K_MSEC(100));
}
static void configure_button_irq(const struct gpio_dt_spec btn)
{
int ret;
if (!device_is_ready(btn.port)) {
printk("Error: button device %s is not ready\n", btn.port->name);
return;
}
ret = gpio_pin_configure_dt(&btn, GPIO_INPUT);
if (ret != 0) {
printk("Error %d: failed to configure %s pin %d\n", ret, btn.port->name, btn.pin);
return;
}
ret = gpio_pin_interrupt_configure_dt(&btn, GPIO_INT_EDGE_TO_ACTIVE);
if (ret != 0) {
printk("Error %d: failed to configure interrupt on %s pin %d\n", ret,
btn.port->name, btn.pin);
return;
}
button_cb_data.pin_mask |= BIT(btn.pin);
gpio_add_callback(btn.port, &button_cb_data);
printk("Set up button at %s pin %d\n", btn.port->name, btn.pin);
}
static void configure_buttons(void)
{
gpio_init_callback(&button_cb_data, button_pressed, 0);
for (int idx = 0; idx < BTN_COUNT; idx++) {
configure_button_irq(btns[idx]);
}
}
static bool eir_found(struct bt_data *data, void *user_data)
{
bt_addr_le_t *addr = user_data;
int i;
switch (data->type) {
case BT_DATA_UUID16_SOME:
case BT_DATA_UUID16_ALL:
if (data->data_len % sizeof(uint16_t) != 0U) {
printk("AD malformed\n");
return true;
}
for (i = 0; i < data->data_len; i += sizeof(uint16_t)) {
struct bt_le_conn_param *param;
struct bt_uuid *uuid;
uint16_t u16;
int err;
(void)memcpy(&u16, &data->data[i], sizeof(u16));
uuid = BT_UUID_DECLARE_16(sys_le16_to_cpu(u16));
if (bt_uuid_cmp(uuid, BT_UUID_OTS) != 0) {
continue;
}
err = bt_le_scan_stop();
if (err != 0) {
printk("Stop LE scan failed (err %d)\n", err);
continue;
}
param = BT_LE_CONN_PARAM_DEFAULT;
err = bt_conn_le_create(addr, BT_CONN_LE_CREATE_CONN, param, &default_conn);
if (err != 0) {
printk("Create conn failed (err %d)\n", err);
start_scan();
}
return false;
}
}
return true;
}
static void device_found(const bt_addr_le_t *addr, int8_t rssi, uint8_t type,
struct net_buf_simple *ad)
{
char dev[BT_ADDR_LE_STR_LEN];
bt_addr_le_to_str(addr, dev, sizeof(dev));
/* We're only interested in connectable events and scan response
* because service UUID is in sd of sample peripheral_ots.
*/
if (type == BT_GAP_ADV_TYPE_ADV_IND || type == BT_GAP_ADV_TYPE_ADV_DIRECT_IND ||
type == BT_GAP_ADV_TYPE_SCAN_RSP) {
bt_data_parse(ad, eir_found, (void *)addr);
}
}
static void start_scan(void)
{
int err;
/* Use active scanning and disable duplicate filtering to handle any
* devices that might update their advertising data at runtime.
*/
struct bt_le_scan_param scan_param = {
.type = BT_LE_SCAN_TYPE_ACTIVE,
.options = BT_LE_SCAN_OPT_NONE,
.interval = BT_GAP_SCAN_FAST_INTERVAL,
.window = BT_GAP_SCAN_FAST_WINDOW,
};
err = bt_le_scan_start(&scan_param, device_found);
if (err != 0) {
printk("Scanning OTS TAG failed to start (err %d)\n", err);
return;
}
printk("Scanning successfully started\n");
}
static int subscribe_func(void)
{
int ret;
printk("Subscribe OACP and OLCP Indication\n");
oacp_sub_params = &otc.oacp_sub_params;
oacp_sub_params->disc_params = &otc.oacp_sub_disc_params;
if (oacp_sub_params) {
/* With ccc_handle == 0 it will use auto discovery */
oacp_sub_params->ccc_handle = 0;
oacp_sub_params->end_handle = otc.end_handle;
oacp_sub_params->value = BT_GATT_CCC_INDICATE;
oacp_sub_params->value_handle = otc.oacp_handle;
oacp_sub_params->notify = bt_ots_client_indicate_handler;
ret = bt_gatt_subscribe(default_conn, oacp_sub_params);
if (ret != 0) {
printk("Subscribe OACP failed %d\n", ret);
return ret;
}
}
olcp_sub_params = &otc.olcp_sub_params;
olcp_sub_params->disc_params = &otc.olcp_sub_disc_params;
if (olcp_sub_params) {
/* With ccc_handle == 0 it will use auto discovery */
olcp_sub_params->ccc_handle = 0;
olcp_sub_params->end_handle = otc.end_handle;
olcp_sub_params->value = BT_GATT_CCC_INDICATE;
olcp_sub_params->value_handle = otc.olcp_handle;
olcp_sub_params->notify = bt_ots_client_indicate_handler;
ret = bt_gatt_subscribe(default_conn, olcp_sub_params);
if (ret != 0) {
printk("Subscribe OLCP failed %d\n", ret);
return ret;
}
}
return ret;
}
static bool is_discovery_complete(void)
{
return (atomic_test_bit(&discovery_state, DISC_OTS_FEATURE) &&
atomic_test_bit(&discovery_state, DISC_OTS_NAME) &&
atomic_test_bit(&discovery_state, DISC_OTS_TYPE) &&
atomic_test_bit(&discovery_state, DISC_OTS_SIZE) &&
atomic_test_bit(&discovery_state, DISC_OTS_ID) &&
atomic_test_bit(&discovery_state, DISC_OTS_PROPERTIES) &&
atomic_test_bit(&discovery_state, DISC_OTS_ACTION_CP) &&
atomic_test_bit(&discovery_state, DISC_OTS_LIST_CP));
}
static uint8_t discover_func(struct bt_conn *conn, const struct bt_gatt_attr *attr,
struct bt_gatt_discover_params *params)
{
int err;
if (!attr) {
printk("Discover complete\n");
(void)memset(params, 0, sizeof(*params));
return BT_GATT_ITER_STOP;
}
if (bt_uuid_cmp(discover_params.uuid, BT_UUID_OTS) == 0) {
(void)memcpy(&uuid, BT_UUID_OTS_FEATURE, sizeof(uuid));
discover_params.uuid = &uuid.uuid;
discover_params.start_handle = attr->handle + 1;
discover_params.type = BT_GATT_DISCOVER_CHARACTERISTIC;
err = bt_gatt_discover(conn, &discover_params);
if (err != 0) {
printk("Discover failed (err %d)\n", err);
}
} else if (bt_uuid_cmp(discover_params.uuid, BT_UUID_OTS_FEATURE) == 0) {
atomic_set_bit(&discovery_state, DISC_OTS_FEATURE);
otc.feature_handle = bt_gatt_attr_value_handle(attr);
(void)memcpy(&uuid, BT_UUID_OTS_NAME, sizeof(uuid));
discover_params.uuid = &uuid.uuid;
discover_params.start_handle = attr->handle + 1;
discover_params.type = BT_GATT_DISCOVER_CHARACTERISTIC;
err = bt_gatt_discover(conn, &discover_params);
if (err != 0) {
printk("Discover failed (err %d)\n", err);
}
} else if (bt_uuid_cmp(discover_params.uuid, BT_UUID_OTS_NAME) == 0) {
atomic_set_bit(&discovery_state, DISC_OTS_NAME);
otc.obj_name_handle = bt_gatt_attr_value_handle(attr);
(void)memcpy(&uuid, BT_UUID_OTS_TYPE, sizeof(uuid));
discover_params.uuid = &uuid.uuid;
discover_params.start_handle = attr->handle + 1;
discover_params.type = BT_GATT_DISCOVER_CHARACTERISTIC;
err = bt_gatt_discover(conn, &discover_params);
if (err != 0) {
printk("Discover failed (err %d)\n", err);
}
} else if (bt_uuid_cmp(discover_params.uuid, BT_UUID_OTS_TYPE) == 0) {
atomic_set_bit(&discovery_state, DISC_OTS_TYPE);
otc.obj_type_handle = bt_gatt_attr_value_handle(attr);
(void)memcpy(&uuid, BT_UUID_OTS_SIZE, sizeof(uuid));
discover_params.uuid = &uuid.uuid;
discover_params.start_handle = attr->handle + 1;
discover_params.type = BT_GATT_DISCOVER_CHARACTERISTIC;
err = bt_gatt_discover(conn, &discover_params);
if (err != 0) {
printk("Discover failed (err %d)\n", err);
}
} else if (bt_uuid_cmp(discover_params.uuid, BT_UUID_OTS_SIZE) == 0) {
atomic_set_bit(&discovery_state, DISC_OTS_SIZE);
otc.obj_size_handle = bt_gatt_attr_value_handle(attr);
(void)memcpy(&uuid, BT_UUID_OTS_ID, sizeof(uuid));
discover_params.uuid = &uuid.uuid;
discover_params.start_handle = attr->handle + 1;
discover_params.type = BT_GATT_DISCOVER_CHARACTERISTIC;
err = bt_gatt_discover(conn, &discover_params);
if (err != 0) {
printk("Discover failed (err %d)\n", err);
}
} else if (bt_uuid_cmp(discover_params.uuid, BT_UUID_OTS_ID) == 0) {
atomic_set_bit(&discovery_state, DISC_OTS_ID);
otc.obj_id_handle = bt_gatt_attr_value_handle(attr);
(void)memcpy(&uuid, BT_UUID_OTS_PROPERTIES, sizeof(uuid));
discover_params.uuid = &uuid.uuid;
discover_params.start_handle = attr->handle + 1;
discover_params.type = BT_GATT_DISCOVER_CHARACTERISTIC;
err = bt_gatt_discover(conn, &discover_params);
if (err != 0) {
printk("Discover failed (err %d)\n", err);
}
} else if (bt_uuid_cmp(discover_params.uuid, BT_UUID_OTS_PROPERTIES) == 0) {
atomic_set_bit(&discovery_state, DISC_OTS_PROPERTIES);
otc.obj_properties_handle = bt_gatt_attr_value_handle(attr);
(void)memcpy(&uuid, BT_UUID_OTS_ACTION_CP, sizeof(uuid));
discover_params.uuid = &uuid.uuid;
discover_params.start_handle = attr->handle + 1;
discover_params.type = BT_GATT_DISCOVER_CHARACTERISTIC;
err = bt_gatt_discover(conn, &discover_params);
if (err != 0) {
printk("Discover failed (err %d)\n", err);
}
} else if (bt_uuid_cmp(discover_params.uuid, BT_UUID_OTS_ACTION_CP) == 0) {
atomic_set_bit(&discovery_state, DISC_OTS_ACTION_CP);
otc.oacp_handle = bt_gatt_attr_value_handle(attr);
(void)memcpy(&uuid, BT_UUID_OTS_LIST_CP, sizeof(uuid));
discover_params.uuid = &uuid.uuid;
discover_params.start_handle = attr->handle + 1;
discover_params.type = BT_GATT_DISCOVER_CHARACTERISTIC;
err = bt_gatt_discover(conn, &discover_params);
if (err != 0) {
printk("Discover failed (err %d)\n", err);
}
} else if (bt_uuid_cmp(discover_params.uuid, BT_UUID_OTS_LIST_CP) == 0) {
atomic_set_bit(&discovery_state, DISC_OTS_LIST_CP);
otc.olcp_handle = bt_gatt_attr_value_handle(attr);
} else {
return BT_GATT_ITER_STOP;
}
if (is_discovery_complete()) {
printk("Discovery complete for OTS Client\n");
err = subscribe_func();
if (err != 0) {
return BT_GATT_ITER_STOP;
}
/* Read feature of OTS server*/
err = bt_ots_client_read_feature(&otc, default_conn);
if (err != 0) {
printk("bt_ots_client_read_feature failed (err %d)", err);
}
}
return BT_GATT_ITER_STOP;
}
static void connected(struct bt_conn *conn, uint8_t err)
{
char addr[BT_ADDR_LE_STR_LEN];
bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));
first_selected = false;
if (err != 0) {
printk("Failed to connect to %s (%u)\n", addr, err);
bt_conn_unref(default_conn);
default_conn = NULL;
start_scan();
return;
}
if (conn != default_conn) {
return;
}
printk("Connected: %s\n", addr);
if (conn == default_conn) {
(void)memcpy(&uuid, BT_UUID_OTS, sizeof(uuid));
discover_params.uuid = &uuid.uuid;
discover_params.func = discover_func;
discover_params.start_handle = BT_ATT_FIRST_ATTRIBUTE_HANDLE;
discover_params.end_handle = BT_ATT_LAST_ATTRIBUTE_HANDLE;
discover_params.type = BT_GATT_DISCOVER_PRIMARY;
err = bt_gatt_discover(default_conn, &discover_params);
if (err != 0) {
printk("Discover failed(err %d)\n", err);
return;
}
}
}
static void disconnected(struct bt_conn *conn, uint8_t reason)
{
char addr[BT_ADDR_LE_STR_LEN];
if (conn != default_conn) {
return;
}
bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));
printk("Disconnected: %s (reason 0x%02x)\n", addr, reason);
bt_conn_unref(default_conn);
default_conn = NULL;
discovery_state = ATOMIC_INIT(0);
start_scan();
}
BT_CONN_CB_DEFINE(conn_callbacks) = {
.connected = connected,
.disconnected = disconnected,
};
static void on_obj_selected(struct bt_ots_client *ots_inst, struct bt_conn *conn, int err)
{
printk("Current object selected cb OLCP result (%d)\n", err);
if (err == BT_GATT_OTS_OLCP_RES_OPERATION_FAILED) {
printk("BT_GATT_OTS_OLCP_RES_OPERATION_FAILED %d\n", err);
first_selected = false;
} else if (err == BT_GATT_OTS_OLCP_RES_OUT_OF_BONDS) {
printk("BT_GATT_OTS_OLCP_RES_OUT_OF_BONDS %d. Select first valid instead\n", err);
(void)bt_ots_client_select_id(&otc, default_conn, BT_OTS_OBJ_ID_MIN);
}
(void)memset(obj_data_buf, 0, OBJ_MAX_SIZE);
}
static int on_obj_data_read(struct bt_ots_client *ots_inst, struct bt_conn *conn, uint32_t offset,
uint32_t len, uint8_t *data_p, bool is_complete)
{
printk("Received OTS Object content, %i bytes at offset %i\n", len, offset);
print_hex_number(data_p, len);
if ((offset + len) > OBJ_MAX_SIZE) {
printk("Can not fit whole object, drop the rest of data\n");
} else {
(void)memcpy((obj_data_buf + offset), data_p, MIN((OBJ_MAX_SIZE - offset), len));
}
if (is_complete) {
printk("Object total received %d\n", len + offset);
print_hex_number(obj_data_buf, len + offset);
(void)memset(obj_data_buf, 0, OBJ_MAX_SIZE);
otc_checksum_work.offset = 0;
otc_checksum_work.len = otc.cur_object.size.cur;
k_work_schedule(&otc_checksum_work.work, K_NO_WAIT);
return BT_OTS_STOP;
}
return BT_OTS_CONTINUE;
}
static void on_obj_metadata_read(struct bt_ots_client *ots_inst, struct bt_conn *conn, int err,
uint8_t metadata_read)
{
printk("Object's meta data:\n");
printk("\tCurrent size\t:%u", ots_inst->cur_object.size.cur);
printk("\tAlloc size\t:%u\n", ots_inst->cur_object.size.alloc);
if (ots_inst->cur_object.size.cur > OBJ_MAX_SIZE) {
printk("Object larger than allocated buffer\n");
}
bt_ots_metadata_display(&ots_inst->cur_object, 1);
}
static void on_obj_data_written(struct bt_ots_client *ots_inst, struct bt_conn *conn, size_t len)
{
int err;
printk("Object been written %d\n", len);
/* Update object size after write done*/
err = bt_ots_client_read_object_metadata(&otc, default_conn,
BT_OTS_METADATA_REQ_ALL);
if (err != 0) {
printk("Failed to read object metadata (err %d)\n", err);
}
}
void on_obj_checksum_calculated(struct bt_ots_client *ots_inst,
struct bt_conn *conn, int err, uint32_t checksum)
{
printk("Object Calculate checksum OACP result (%d)\nChecksum 0x%08x last sent 0x%08x %s\n",
err, checksum, last_checksum, (checksum == last_checksum) ? "match" : "not match");
}
static void bt_otc_init(void)
{
otc_cb.obj_data_read = on_obj_data_read;
otc_cb.obj_selected = on_obj_selected;
otc_cb.obj_metadata_read = on_obj_metadata_read;
otc_cb.obj_data_written = on_obj_data_written;
otc_cb.obj_checksum_calculated = on_obj_checksum_calculated;
otc.start_handle = BT_ATT_FIRST_ATTRIBUTE_HANDLE;
otc.end_handle = BT_ATT_LAST_ATTRIBUTE_HANDLE;
printk("Current object selected callback: %p\n", otc_cb.obj_selected);
printk("Content callback: %p\n", otc_cb.obj_data_read);
printk("Metadata callback: %p\n", otc_cb.obj_metadata_read);
otc.cb = &otc_cb;
bt_ots_client_register(&otc);
}
int main(void)
{
int err;
first_selected = false;
discovery_state = ATOMIC_INIT(0);
k_work_init_delayable(&otc_btn_work.work, otc_btn_work_fn);
k_work_init_delayable(&otc_checksum_work.work, otc_checksum_work_fn);
configure_buttons();
err = bt_enable(NULL);
if (err != 0) {
printk("Bluetooth init failed (err %d)\n", err);
return 0;
}
bt_otc_init();
printk("Bluetooth OTS client sample running\n");
start_scan();
return 0;
}