shoes_project/touch_floor_by_imu/ble_cfg/host.c

#include "ble_comm.h"

#if USENAMEFR
char Target_scan[TARFET_LEN_MAX] = "SH_E9F4";
#else
char Target_scan[TARFET_LEN_MAX] = {0x01, 0xf9, 0x84, 0x6a, 0x83, 0xeb};
#endif

static Ble_receive_handler_t Rec_h = NULL;

#define APP_BLE_CONN_CFG_TAG 1                           /**< Tag that refers to the BLE stack configuration set with @ref sd_ble_cfg_set. The default tag is @ref BLE_CONN_CFG_TAG_DEFAULT. */
#define APP_BLE_OBSERVER_PRIO 3                          /**< BLE observer priority of the application. There is no need to modify this value. */
#define UART_TX_BUF_SIZE 1024                            /**< UART TX buffer size. */
#define UART_RX_BUF_SIZE 1024                            /**< UART RX buffer size. */
#define NUS_SERVICE_UUID_TYPE BLE_UUID_TYPE_VENDOR_BEGIN /**< UUID type for the Nordic UART Service (vendor specific). */
#define ECHOBACK_BLE_UART_DATA 1                         /**< Echo the UART data that is received over the Nordic UART Service (NUS) back to the sender. */
BLE_NUS_C_DEF(m_ble_nus_c);                              /**< BLE Nordic UART Service (NUS) client instance. */
NRF_BLE_GATT_DEF(m_gatt);                                /**< GATT module instance. */
BLE_DB_DISCOVERY_DEF(m_db_disc);                         /**< Database discovery module instance. */
NRF_BLE_SCAN_DEF(m_scan);                                /**< Scanning Module instance. */
NRF_BLE_GQ_DEF(m_ble_gatt_queue,                         /**< BLE GATT Queue instance. */
               NRF_SDH_BLE_CENTRAL_LINK_COUNT,
               NRF_BLE_GQ_QUEUE_SIZE);
static uint16_t m_ble_nus_max_data_len = BLE_GATT_ATT_MTU_DEFAULT - OPCODE_LENGTH - HANDLE_LENGTH; /**< Maximum length of data (in bytes) that can be transmitted to the peer by the Nordic UART service module. */
unsigned char connect_to_server = 0;
ble_gap_conn_params_t host_conn_params = {0};
static void db_disc_handler(ble_db_discovery_evt_t *p_evt)
{
    ble_nus_c_on_db_disc_evt(&m_ble_nus_c, p_evt);
}
void timer_init(void)
{
    ret_code_t err_code = app_timer_init();
    APP_ERROR_CHECK(err_code);
}
static void db_discovery_init(void)
{
    ble_db_discovery_init_t db_init;

    memset(&db_init, 0, sizeof(ble_db_discovery_init_t));

    db_init.evt_handler = db_disc_handler;
    db_init.p_gatt_queue = &m_ble_gatt_queue;

    ret_code_t err_code = ble_db_discovery_init(&db_init);
    APP_ERROR_CHECK(err_code);
}
void power_management_init(void)
{
    ret_code_t err_code;
    err_code = nrf_pwr_mgmt_init();
    APP_ERROR_CHECK(err_code);
}
static void gatt_evt_handler(nrf_ble_gatt_t *p_gatt, nrf_ble_gatt_evt_t const *p_evt)
{
    if (p_evt->evt_id == NRF_BLE_GATT_EVT_ATT_MTU_UPDATED)
    {
        BLE_PRINT("GATT MTU exchange completed.\r\r\n");

        m_ble_nus_max_data_len = p_evt->params.att_mtu_effective - OPCODE_LENGTH - HANDLE_LENGTH;
        BLE_PRINT("Ble NUS max data length set to 0x%X(%d)\r\r\n", m_ble_nus_max_data_len, m_ble_nus_max_data_len);
    }
}
void gatt_init(void)
{
    ret_code_t err_code;

    err_code = nrf_ble_gatt_init(&m_gatt, gatt_evt_handler);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_ble_gatt_att_mtu_central_set(&m_gatt, NRF_SDH_BLE_GATT_MAX_MTU_SIZE);
    APP_ERROR_CHECK(err_code);
	
	  err_code = nrf_ble_gatt_att_mtu_periph_set(&m_gatt, NRF_SDH_BLE_GATT_MAX_MTU_SIZE);
    APP_ERROR_CHECK(err_code);
}
void scan_start(void)
{
    ret_code_t ret;

	if(connect_to_server)return;
    ret = nrf_ble_scan_start(&m_scan);
    APP_ERROR_CHECK(ret);
	BLE_PRINT("scan_start -> scan_name  <%s> \r\n", Target_scan);
}
static void ble_nus_c_evt_handler(ble_nus_c_t *p_ble_nus_c, ble_nus_c_evt_t const *p_ble_nus_evt)
{
    ret_code_t err_code;

    switch (p_ble_nus_evt->evt_type)
    {
    case BLE_NUS_C_EVT_DISCOVERY_COMPLETE:
        BLE_PRINT("Discovery complete.\r\n");
        err_code = ble_nus_c_handles_assign(p_ble_nus_c, p_ble_nus_evt->conn_handle, &p_ble_nus_evt->handles);
        APP_ERROR_CHECK(err_code);

        err_code = ble_nus_c_tx_notif_enable(p_ble_nus_c);
        APP_ERROR_CHECK(err_code);
        BLE_PRINT("Connected to device with Nordic UART Service.\r\n");
        break;

    case BLE_NUS_C_EVT_NUS_TX_EVT: //作为主机接收从机的数据
        Rec_h(p_ble_nus_evt->p_data, p_ble_nus_evt->data_len);
        break;

    case BLE_NUS_C_EVT_DISCONNECTED:
        BLE_PRINT("Disconnected.\r\n");
#if		DEBUGBLE
        scan_start();
#endif
        break;
    }
}
static void nus_error_handler(uint32_t nrf_error)
{
    if (nrf_error == NRF_ERROR_RESOURCES)
        return;
		if (nrf_error == NRF_ERROR_INVALID_STATE)
        return;
    APP_ERROR_HANDLER(nrf_error);
}
static void nus_c_init(void)
{
    ret_code_t err_code;
    ble_nus_c_init_t init;

    init.evt_handler = ble_nus_c_evt_handler;
    init.error_handler = nus_error_handler;
    init.p_gatt_queue = &m_ble_gatt_queue;

    err_code = ble_nus_c_init(&m_ble_nus_c, &init);
    APP_ERROR_CHECK(err_code);
}

#define host_connected_evt_num_max 3
static uint8_t host_connected_evt_num = 0;
static Ble_evt_cb ble_host_connected_evt_cb[host_connected_evt_num_max] = {0};
int Ble_Host_Connectd_Evt_Regist(Ble_evt_cb cb)
{
    for (int i = 0; i < host_connected_evt_num_max; i++)
    {
        if (ble_host_connected_evt_cb[i] == cb)
            return -1;
        if (ble_host_connected_evt_cb[i] == 0)
        {
            host_connected_evt_num++;
            ble_host_connected_evt_cb[i] = cb; //回调函数
            return 0;
        }
    }
    SEGGER_RTT_printf(0, "ble_evt_Regist -> too many!\n");
    return -2;
}

void ble_host_connected_evt_pcs(void)
{
    for (int i = 0; i < host_connected_evt_num; i++)
    { //SEGGER_RTT_printf(0,"time_cb[%d]=%d\n",i,time_cb[i]);
        if (ble_host_connected_evt_cb[i])
        {
            ble_host_connected_evt_cb[i](); //回调函数
        }
    }
}

#define host_disconn_evt_num_max 16
static uint8_t host_disconn_evt_num = 0;
static Ble_evt_cb ble_Host_disconn_evt_cb[host_disconn_evt_num_max] = {0};
int Ble_Host_Disconn_Evt_Regist(Ble_evt_cb cb)
{
    for (int i = 0; i < host_disconn_evt_num_max; i++)
    {
        if (ble_Host_disconn_evt_cb[i] == cb)
            return -1;
        if (ble_Host_disconn_evt_cb[i] == 0)
        {
            host_disconn_evt_num++;
            ble_Host_disconn_evt_cb[i] = cb; //回调函数
            return 0;
        }
    }
    SEGGER_RTT_printf(0, "Ble_Slave_Disconn_Evt_Regist -> too many!\r\n");
    return -2;
}

void ble_host_dicconn_evt_pcs(void)
{
    for (int i = 0; i < host_disconn_evt_num; i++)
    { //SEGGER_RTT_printf(0,"time_cb[%d]=%d\n",i,time_cb[i]);
        if (ble_Host_disconn_evt_cb[i])
        {
            ble_Host_disconn_evt_cb[i](); //回调函数
        }
    }
}

static void on_ble_central_evt(ble_evt_t const *p_ble_evt, void *p_context) //作为主设备时的处理
{
    ret_code_t err_code;
    ble_gap_evt_t const *p_gap_evt = &p_ble_evt->evt.gap_evt;

    switch (p_ble_evt->header.evt_id)
    {
    case BLE_GAP_EVT_CONNECTED:
        err_code = ble_nus_c_handles_assign(&m_ble_nus_c, p_ble_evt->evt.gap_evt.conn_handle, NULL);
        APP_ERROR_CHECK(err_code);

        BLE_PRINT("start discovery services\r\n"); //添加开始发现服务提示
        connect_to_server = 1;
		gpio_mt_run(500);
        // start discovery of services. The NUS Client waits for a discovery result
        err_code = ble_db_discovery_start(&m_db_disc, p_ble_evt->evt.gap_evt.conn_handle);
        APP_ERROR_CHECK(err_code);
        ble_host_connected_evt_pcs();

        sd_ble_gap_rssi_start(m_ble_nus_c.conn_handle, BLE_GAP_RSSI_THRESHOLD_INVALID, 0);
        break;

    case BLE_GAP_EVT_DISCONNECTED:
        connect_to_server = 0;
        BLE_PRINT("Disconnected. conn_handle: 0x%x, reason: 0x%x",
                  p_gap_evt->conn_handle,
                  p_gap_evt->params.disconnected.reason);
        BLE_PRINT("Disconnected to Server.\r\n");
        ble_host_dicconn_evt_pcs();

        sd_ble_gap_rssi_stop(m_ble_nus_c.conn_handle);
        break;

    case BLE_GAP_EVT_TIMEOUT:
        if (p_gap_evt->params.timeout.src == BLE_GAP_TIMEOUT_SRC_CONN)
        {
            BLE_PRINT("Connection Request timed out.\r\n");
        }
        break;

    case BLE_GAP_EVT_SEC_PARAMS_REQUEST:
        // Pairing not supported.
        err_code = sd_ble_gap_sec_params_reply(p_ble_evt->evt.gap_evt.conn_handle, BLE_GAP_SEC_STATUS_PAIRING_NOT_SUPP, NULL, NULL);
        APP_ERROR_CHECK(err_code);
        BLE_PRINT("on_ble_central_evt -> BLE_GAP_EVT_SEC_PARAMS_REQUEST\r\n");
        break;

    case BLE_GAP_EVT_PHY_UPDATE_REQUEST:
    {
        BLE_PRINT("Connection 0x%x PHY update request.", p_ble_evt->evt.gap_evt.conn_handle);
        ble_gap_phys_t const phys =
            {
                .rx_phys = BLE_GAP_PHY_AUTO,
                .tx_phys = BLE_GAP_PHY_AUTO,
            };
        err_code = sd_ble_gap_phy_update(p_ble_evt->evt.gap_evt.conn_handle, &phys);
        APP_ERROR_CHECK(err_code);
    }
    break;

    case BLE_GAP_EVT_CONN_PARAM_UPDATE_REQUEST:
        // Accepting parameters requested by peer.
        err_code = sd_ble_gap_conn_param_update(p_gap_evt->conn_handle,
                                                &p_gap_evt->params.conn_param_update_request.conn_params); //主机接受从机连接参数更新连接参数
        APP_ERROR_CHECK(err_code);
        BLE_PRINT("on_ble_central_evt -> BLE_GAP_EVT_CONN_PARAM_UPDATE_REQUEST\r\n");
        break;

    case BLE_GAP_EVT_CONN_PARAM_UPDATE:
			
        BLE_PRINT("on_ble_central_evt -> BLE_GAP_EVT_CONN_PARAM_UPDATE\r\n");
        memcpy(&host_conn_params, &p_gap_evt->params.conn_param_update_request.conn_params, sizeof(ble_gap_conn_params_t));
        BLE_PRINT("min_conn_interval : %d * 1.25 ms\r\n", p_gap_evt->params.conn_param_update_request.conn_params.min_conn_interval);
        BLE_PRINT("max_conn_interval : %d * 1.25 ms\r\n", p_gap_evt->params.conn_param_update_request.conn_params.max_conn_interval);
        BLE_PRINT("slave_latency     : %d\r\n", p_gap_evt->params.conn_param_update_request.conn_params.slave_latency);
        BLE_PRINT("conn_sup_timeout  : %d * 10   ms\r\n", p_gap_evt->params.conn_param_update_request.conn_params.conn_sup_timeout);
        break;

    case BLE_GATTC_EVT_TIMEOUT:
        // Disconnect on GATT Client timeout event.
        BLE_PRINT("GATT Client Timeout.\r\n");
        err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gattc_evt.conn_handle,
                                         BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
        APP_ERROR_CHECK(err_code);
        break;

    case BLE_GATTS_EVT_TIMEOUT:
        // Disconnect on GATT Server timeout event.
        BLE_PRINT("GATT Server Timeout.\r\n");
        err_code = sd_ble_gap_disconnect(p_ble_evt->evt.gatts_evt.conn_handle,
                                         BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
        APP_ERROR_CHECK(err_code);
        break;

    default:
        break;
    }
}
extern bool ble_evt_is_advertising_timeout(ble_evt_t const *p_ble_evt);
extern void on_ble_peripheral_evt(ble_evt_t const *p_ble_evt); //作为从设备的处理
static void ble_evt_handler(ble_evt_t const *p_ble_evt, void *p_context)
{
    uint16_t conn_handle = p_ble_evt->evt.gap_evt.conn_handle;
    uint16_t role = ble_conn_state_role(conn_handle);

    // Based on the role this device plays in the connection, dispatch to the right handler.不同角色下所做的处理
    if (role == BLE_GAP_ROLE_PERIPH || ble_evt_is_advertising_timeout(p_ble_evt))
    {
        //			  ble_nus_on_ble_evt(p_ble_evt, &m_nus);
        on_ble_peripheral_evt(p_ble_evt);
    }
    else if ((role == BLE_GAP_ROLE_CENTRAL) || (p_ble_evt->header.evt_id == BLE_GAP_EVT_ADV_REPORT))
    {
        //        ble_nus_c_on_ble_evt(p_ble_evt, &m_ble_nus_c);
        on_ble_central_evt(p_ble_evt, NULL);
    }
    else
    {
        BLE_PRINT("ble_evt_handler -> other\r\n");
    }
}
void ble_stack_init(void)
{
    ret_code_t err_code;

    err_code = nrf_sdh_enable_request();
    APP_ERROR_CHECK(err_code);

    // Configure the BLE stack using the default settings.
    // Fetch the start address of the application RAM.
    uint32_t ram_start = 0;
    err_code = nrf_sdh_ble_default_cfg_set(APP_BLE_CONN_CFG_TAG, &ram_start);
    APP_ERROR_CHECK(err_code);

    // Enable BLE stack.
    err_code = nrf_sdh_ble_enable(&ram_start);
    APP_ERROR_CHECK(err_code);

    // Register a handler for BLE events.
    NRF_SDH_BLE_OBSERVER(m_ble_observer, APP_BLE_OBSERVER_PRIO, ble_evt_handler, NULL);
}
#define PRINT_MAC 0
/**@brief Function for handling Scanning Module events.
 */
static void scan_evt_handler(scan_evt_t const *p_scan_evt)
{
    ret_code_t err_code;

    switch (p_scan_evt->scan_evt_id)
    {
    case NRF_BLE_SCAN_EVT_CONNECTING_ERROR:
    {
        err_code = p_scan_evt->params.connecting_err.err_code;
        APP_ERROR_CHECK(err_code);
        BLE_PRINT("scan_evt_handler -> NRF_BLE_SCAN_EVT_CONNECTING_ERROR \r\n");
    }
    break;

    case NRF_BLE_SCAN_EVT_CONNECTED:
    {
        BLE_PRINT("scan_evt_handler -> NRF_BLE_SCAN_EVT_CONNECTED\r\n");
#if PRINT_MAC
        ble_gap_evt_connected_t const *p_connected =
            p_scan_evt->params.connected.p_connected;
        // Scan is automatically stopped by the connection.
        BLE_PRINT("Connecting to Host %02x%02x %02x%02x %02x%02x\r\r\n",
                  p_connected->peer_addr.addr[0],
                  p_connected->peer_addr.addr[1],
                  p_connected->peer_addr.addr[2],
                  p_connected->peer_addr.addr[3],
                  p_connected->peer_addr.addr[4],
                  p_connected->peer_addr.addr[5]);
#endif
    }
    break;

    case NRF_BLE_SCAN_EVT_SCAN_TIMEOUT:
    {
        BLE_PRINT("scan_evt_handler -> NRF_BLE_SCAN_EVT_SCAN_TIMEOUT -> Scan timed out.\r\n");
        scan_start();
    }
    break;

    case NRF_BLE_SCAN_EVT_FILTER_MATCH:
    {
        BLE_PRINT("scan_evt_handler -> NRF_BLE_SCAN_EVT_FILTER_MATCH\r\n");
    }
    break;

    case NRF_BLE_SCAN_EVT_WHITELIST_REQUEST:
    {
        BLE_PRINT("scan_evt_handler -> NRF_BLE_SCAN_EVT_WHITELIST_REQUEST\r\n");
    }
    break;

    case NRF_BLE_SCAN_EVT_WHITELIST_ADV_REPORT:
    {
        BLE_PRINT("scan_evt_handler -> NRF_BLE_SCAN_EVT_WHITELIST_ADV_REPORT\r\n");
    }
    break;

    case NRF_BLE_SCAN_EVT_NOT_FOUND:
    {
        //						 BLE_PRINT("scan_evt_handler -> NRF_BLE_SCAN_EVT_NOT_FOUND");
    }
    break;

    default:
        BLE_PRINT("scan_evt_handler -> default:%d \r\n", p_scan_evt->scan_evt_id);
        break;
    }
}

unsigned int send_bytes_server(uint8_t *bytes, uint16_t len)
{
    if (connect_to_server == 0)
    {
        BLE_PRINT("send_bytes_server -> APP_ERR_DISCONN\r\n");
        return APP_ERR_DISCONN;
    }
    if (len > m_ble_nus_max_data_len)
    {
        BLE_PRINT("send_bytes_server -> fail ->overlength\r\n");
        return APP_ERR_OVERLENGTH;
    }
    if (NRF_SUCCESS != ble_nus_c_string_send(&m_ble_nus_c, bytes, len))
    {
        BLE_PRINT("send_bytes_server -> fail\r\n");
    }
    return APP_SUCCESS;
}

static void scan_init(void)
{
    ret_code_t err_code;
    nrf_ble_scan_init_t init_scan;

    memset(&init_scan, 0, sizeof(init_scan));

    init_scan.connect_if_match = true;
    init_scan.conn_cfg_tag = APP_BLE_CONN_CFG_TAG;

    err_code = nrf_ble_scan_init(&m_scan, &init_scan, scan_evt_handler);
    APP_ERROR_CHECK(err_code);

#if USENAMEFR
    err_code = nrf_ble_scan_filter_set(&m_scan, SCAN_NAME_FILTER, &Target_scan);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_ble_scan_filters_enable(&m_scan, NRF_BLE_SCAN_NAME_FILTER, false);
    APP_ERROR_CHECK(err_code);
    BLE_PRINT("scan_init -> scan_name  <%s> \r\n", Target_scan);
#else
    err_code = nrf_ble_scan_filter_set(&m_scan, SCAN_ADDR_FILTER, &Target_scan);
    APP_ERROR_CHECK(err_code);

    err_code = nrf_ble_scan_filters_enable(&m_scan, NRF_BLE_SCAN_ADDR_FILTER, false);
    APP_ERROR_CHECK(err_code);

    BLE_PRINT("scan_start -> scan_MAC [ %02X %02X %02X %02X %02X %02X ]\r\n", Target_scan[0], Target_scan[1], Target_scan[2], Target_scan[3], Target_scan[4], Target_scan[5]);

#endif
}

unsigned char host_isconnect(void)
{
    return connect_to_server;
}
char ble_stack_init_sta = 1;
char host_init_sta = 0;
void host_init(Ble_receive_handler_t receive_handler)
{
    if (receive_handler == NULL)
    {
        BLE_PRINT("host_init -> param err \r\n");
        return;
    }
    Rec_h = receive_handler;
    if (ble_stack_init_sta)
    {
        timer_init();            //
        power_management_init(); //
        ble_stack_init();        //
        gatt_init();             //
        ble_stack_init_sta = 0;
    }

    db_discovery_init();
    nus_c_init();

    scan_init();
		host_init_sta=1;
}

void err(int err_num)
{
    BLE_PRINT("APP ERROR -> %d \r\n", err_num);
}

unsigned int host_set_scan_name(char *name, int len)
{
	unsigned int err_code;
    if (len > TARFET_LEN_MAX)
        return APP_ERR_OVERLENGTH;
		if(connect_to_server)
				return APP_ERR_CONNECTED;
		memset(Target_scan, 0, TARFET_LEN_MAX);
		if(host_init_sta)
		{
			memcpy(Target_scan, name, len);
					err_code =nrf_ble_scan_all_filter_remove(&m_scan);
					APP_ERROR_CHECK(err_code);
			#if USENAMEFR
					err_code = nrf_ble_scan_filter_set(&m_scan, SCAN_NAME_FILTER, &Target_scan);
					APP_ERROR_CHECK(err_code);

					err_code = nrf_ble_scan_filters_enable(&m_scan, NRF_BLE_SCAN_NAME_FILTER, false);
					APP_ERROR_CHECK(err_code);
					BLE_PRINT("host_set_scan_name -> scan_name  <%s> \r\n", Target_scan);
			#else
					err_code = nrf_ble_scan_filter_set(&m_scan, SCAN_ADDR_FILTER, &Target_scan);
					APP_ERROR_CHECK(err_code);

					err_code = nrf_ble_scan_filters_enable(&m_scan, NRF_BLE_SCAN_ADDR_FILTER, false);
					APP_ERROR_CHECK(err_code);

					BLE_PRINT("host_set_scan_name -> scan_MAC [ %02X %02X %02X %02X %02X %02X ]\r\n", Target_scan[0], Target_scan[1], Target_scan[2], Target_scan[3], Target_scan[4], Target_scan[5]);

			#endif
		}
		else
		{
			memcpy(Target_scan, name, len);
		}
    return APP_SUCCESS;
}

unsigned int Ble_update_conn_interval(float min_conn_interval, float max_conn_interval)
{
    ret_code_t err_code;
    ble_gap_conn_params_t bgcp;
    //主机接受从机连接参数更新连接参数
	
    if (connect_to_server)
    {	
				if ((max_conn_interval > 1.25 * 1599) || (max_conn_interval < min_conn_interval))
						return APP_ERR_PARAMERR;
				if (min_conn_interval < 7.5f)
						return APP_ERR_PARAMERR;
				bgcp.max_conn_interval = MSEC_TO_UNITS(max_conn_interval, UNIT_1_25_MS);
				bgcp.min_conn_interval = MSEC_TO_UNITS(min_conn_interval, UNIT_1_25_MS);
				bgcp.conn_sup_timeout = MSEC_TO_UNITS(4000, UNIT_10_MS);
				bgcp.slave_latency = 0;
				
        err_code = sd_ble_gap_conn_param_update(m_ble_nus_c.conn_handle, &bgcp);
				if(err_code != NRF_ERROR_INVALID_STATE && err_code != NRF_ERROR_BUSY && err_code != NRF_SUCCESS){
					APP_ERROR_CHECK(err_code);
				}
        return err_code;
    }
    else
    {
        return APP_ERR_DISCONN;
    }
}

void host_disconnect(void)
{
    if (connect_to_server)
        sd_ble_gap_disconnect(m_ble_nus_c.conn_handle, BLE_HCI_REMOTE_USER_TERMINATED_CONNECTION);
}
void host_get_conn_params(ble_gap_conn_params_t *p)
{
    memcpy(p, &host_conn_params, sizeof(ble_gap_conn_params_t));
}
static signed char rssi = 0;
signed char host_get_rssi(void)
{
    unsigned char channel;
    if (connect_to_server == 0)
        return 1;
    sd_ble_gap_rssi_get(m_ble_nus_c.conn_handle, &rssi, &channel);
    ///BLE_PRINT("rssi= %d  channel=%d\r\n", rssi, channel);
    return rssi;
}