Disconnection between "ble_app_hrs" example in SDK 15.2.0 and "heart_rate_collector" example with pc-ble-driver (c/c++)

Question

Hello, this is Kwonjoon Lee, beginner of BLE development. 
 I successfully installed pc-ble-driver (c/c++) in accordance with Git-Hub guide ( https://github.com/NordicSemiconductor/pc-ble-driver ), and I would like to ask about disconnection between "ble_app_hrs" example in SDK 15.2.0 and "heart_rate_collector" example with pc-ble-driver (c/c++). 
 The following is my development environment and procedure, which I faced disconnection. 
 (Development Environment) 
 - Windows 10, 64bit - Visual Studio 2015 Pro - PC-BLE-DRIVER (C/C++) - nRF5 SDK v15.2.0_9412b96 
 - nRF Connect v2.6.0 - SEGGER Embedded Studio for ARM V4.12 (x86) 
 - BLE Peripheral : nRF52840 DK with "ble_app_hrs" example of nRF5 SDK 15.2.0_9412b96 1) Example Path : C:\Nordic
RF5_SDK_15.2.0_9412b96\examples\ble_peripheral\ble_app_hrs\pca10056\s140\ses - BLE Master : nRF52840 Dongle with "heart_rate_collector_v6" example of pc-ble-driver 1) Connectivity Hex File : "connectivity_1.0.0_usb_with_s140_6.1.0.hex" in pc-ble-driver connectivity hex file 2) Baud Rate : 1 Mbps @ COM6 
 (Development Procedure & Disconnection Phenomenon) 
 
 Programming "connectivity_1.0.0_usb_with_s140_6.1.0.hex" into nRF52840 Dongle with nRF Connect Programmer App. in accordance with ( https://devzone.nordicsemi.com/tutorials/b/getting-started/posts/nrf52840-dongle-programming-tutorial ) 
 Building, downloading, executing "ble_app_hrs" example on nRF52840 DK with SEGGER Embedded Studio for ARM V4.12 (x86) in accordance with ( https://www.nordicsemi.com/DocLib/Content/User_Guides/gsg_ses/latest/UG/gsg/intro ) 
 Build & run "heart_rate_collector_v6" example of pc-ble-driver 
 Disconnection after connection establishing & receiving 5 heart rate samples 
 
 (Question) 
 
 I am a beginner of BLE development and I would like to ask whether above disconnection after connection establishing & receiving 5 heart rate samples is normal and expected phenomenon. 
 Additionally, I want to ask what is the meaning of "un-handled event with ID : 18" and "disconnected reason : 0x22" and also, I want to know where can I check the "un-handled event with ID : 18" and "disconnected reason : 0x22" 
 Is there any documentation including operation of "ble_app_hrs" example for beginner? Currently, I am just checking the "ble_app_hrs" example codes in SES, but code line is too long so that I cannot easily understand the operation. 
 
 If anyone give me some comments, it will be huge help for me. Best regards, Kwonjoon Lee

Sigurd · Accepted Answer

Hi, 1) No, this is not the expected behavior. 2) Looking at the list here , we see that event 18 (0x12) is the same as BLE_GAP_EVT_CONN_PARAM_UPDATE. This is an event informing you that the connection parameters have been changed. Disconnect reason 0x22 is BLE_HCI_STATUS_CODE_LMP_RESPONSE_TIMEOUT . I see in the list that you also have another un-handled event with id=35, that is a BLE_GAP_EVT_DATA_LENGTH_UPDATE_REQUEST. This event needs to handled, or else you will disconnect, so this is the event that is causing the disconnect. This is something that the pc-ble-driver examples should have handled. Here is how you can handle the BLE_GAP_EVT_DATA_LENGTH_UPDATE_REQUEST event: Snippet: static void on_conn_data_length_update_request(const ble_gattc_evt_t * const p_ble_gattc_evt) { printf("BLE_GAP_EVT_DATA_LENGTH_UPDATE_REQUEST received "); ble_gap_data_length_params_t const dlp = { .max_rx_octets = 27, .max_tx_octets = 27, .max_rx_time_us = BLE_GAP_DATA_LENGTH_AUTO, .max_tx_time_us = BLE_GAP_DATA_LENGTH_AUTO, }; ble_gap_data_length_limitation_t dll = { 0 }; uint32_t err_code = sd_ble_gap_data_length_update(m_adapter, m_connection_handle, &dlp, &dll); if (err_code != NRF_SUCCESS) { printf("sd_ble_gap_data_length_update failed, err_code %d ", err_code); } } In ble_evt_dispatch() you will need this: case BLE_GAP_EVT_DATA_LENGTH_UPDATE_REQUEST: on_conn_data_length_update_request(&(p_ble_evt->evt.gattc_evt)); break; Complete main.c: /* * copyright (c) 2012 - 2018, nordic semiconductor asa * all rights reserved. * * redistribution and use in source and binary forms, with or without modification, * are permitted provided that the following conditions are met: * * 1. redistributions of source code must retain the above copyright notice, this * list of conditions and the following disclaimer. * * 2. redistributions in binary form, except as embedded into a nordic * semiconductor asa integrated circuit in a product or a software update for * such product, must reproduce the above copyright notice, this list of * conditions and the following disclaimer in the documentation and/or other * materials provided with the distribution. * * 3. Neither the name of Nordic Semiconductor ASA nor the names of its * contributors may be used to endorse or promote products derived from this * software without specific prior written permission. * * 4. This software, with or without modification, must only be used with a * Nordic Semiconductor ASA integrated circuit. * * 5. Any software provided in binary form under this license must not be reverse * engineered, decompiled, modified and/or disassembled. * * THIS SOFTWARE IS PROVIDED BY NORDIC SEMICONDUCTOR ASA "AS IS" AND ANY EXPRESS * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY, NONINFRINGEMENT, AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL NORDIC SEMICONDUCTOR ASA OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /**@example examples/heart_rate_collector * * @brief Heart Rate Collector Sample Application main file. * * This file contains the source code for a sample application that acts as a BLE Central device. * This application scans for a Heart Rate Sensor device and reads it's heart rate data. * https://www.bluetooth.com/specifications/gatt/viewer?attributeXmlFile=org.bluetooth.service.heart_rate.xml * * Structure of this file * - Includes * - Definitions * - Global variables * - Global functions * - Event functions * - Event dispatcher * - Main */ /** Includes */ #include "ble.h" #include "sd_rpc.h" #include #include #include /** Definitions */ #ifdef _WIN32 #define DEFAULT_UART_PORT_NAME "COM6" #define DEFAULT_BAUD_RATE 1000000 /**< The baud rate to be used for serial communication with nRF5 device. */ #endif #ifdef __APPLE__ #define DEFAULT_UART_PORT_NAME "/dev/tty.usbmodem00000" #define DEFAULT_BAUD_RATE 115200 /* 1M baud rate is not supported on MacOS */ #endif #ifdef __linux__ #define DEFAULT_UART_PORT_NAME "/dev/ttyACM0" #define DEFAULT_BAUD_RATE 1000000 #endif enum { UNIT_0_625_MS = 625, /**< Number of microseconds in 0.625 milliseconds. */ UNIT_1_25_MS = 1250, /**< Number of microseconds in 1.25 milliseconds. */ UNIT_10_MS = 10000 /**< Number of microseconds in 10 milliseconds. */ }; #define MSEC_TO_UNITS(TIME, RESOLUTION) (((TIME) * 1000) / (RESOLUTION)) #define SCAN_INTERVAL 0x00A0 /**< Determines scan interval in units of 0.625 milliseconds. */ #define SCAN_WINDOW 0x0050 /**< Determines scan window in units of 0.625 milliseconds. */ #define SCAN_TIMEOUT 0x0 /**< Scan timeout between 0x01 and 0xFFFF in seconds, 0x0 disables timeout. */ #define MIN_CONNECTION_INTERVAL MSEC_TO_UNITS(200, UNIT_1_25_MS) /**< Determines minimum connection interval in milliseconds. */ #define MAX_CONNECTION_INTERVAL MSEC_TO_UNITS(300, UNIT_1_25_MS) /**< Determines maximum connection interval in milliseconds. */ #define SLAVE_LATENCY 0 /**< Slave Latency in number of connection events. */ #define CONNECTION_SUPERVISION_TIMEOUT MSEC_TO_UNITS(4000, UNIT_10_MS) /**< Determines supervision time-out in units of 10 milliseconds. */ #define TARGET_DEV_NAME "Nordic_HRM" /**< Connect to a peripheral using a given advertising name here. */ #define MAX_PEER_COUNT 1 /**< Maximum number of peer's application intends to manage. */ #define BLE_UUID_HEART_RATE_SERVICE 0x180D /**< Heart Rate service UUID. */ #define BLE_UUID_HEART_RATE_MEASUREMENT_CHAR 0x2A37 /**< Heart Rate Measurement characteristic UUID. */ #define BLE_UUID_CCCD 0x2902 #define BLE_CCCD_NOTIFY 0x01 #define STRING_BUFFER_SIZE 50 typedef struct { uint8_t * p_data; /**< Pointer to data. */ uint16_t data_len; /**< Length of data. */ } data_t; /** Global variables */ static uint8_t m_connected_devices = 0; static uint16_t m_connection_handle = 0; static uint16_t m_service_start_handle = 0; static uint16_t m_service_end_handle = 0; static uint16_t m_hrm_char_handle = 0; static uint16_t m_hrm_cccd_handle = 0; static bool m_connection_is_in_progress = false; static adapter_t * m_adapter = NULL; #if NRF_SD_BLE_API >= 5 static uint32_t m_config_id = 1; #endif #if NRF_SD_BLE_API >= 6 static uint8_t mp_data[100] = { 0 }; static ble_data_t m_adv_report_buffer; #endif static const ble_gap_scan_params_t m_scan_param = { #if NRF_SD_BLE_API >= 6 0, // Set if accept extended advertising packetets. 0, // Set if report inomplete reports. #endif 0, // Set if active scanning. #if NRF_SD_BLE_API < 6 0, // Set if selective scanning. #endif #if NRF_SD_BLE_API >= 6 BLE_GAP_SCAN_FP_ACCEPT_ALL, BLE_GAP_PHY_1MBPS, #endif #if NRF_SD_BLE_API == 2 NULL, // Set white-list. #endif #if NRF_SD_BLE_API == 3 || NRF_SD_BLE_API == 5 0, // Set adv_dir_report. #endif (uint16_t)SCAN_INTERVAL, (uint16_t)SCAN_WINDOW, (uint16_t)SCAN_TIMEOUT #if NRF_SD_BLE_API >= 6 , { 0 } // Set chennel mask. #endif }; static const ble_gap_conn_params_t m_connection_param = { (uint16_t)MIN_CONNECTION_INTERVAL, (uint16_t)MAX_CONNECTION_INTERVAL, (uint16_t)SLAVE_LATENCY, (uint16_t)CONNECTION_SUPERVISION_TIMEOUT }; /** Global functions */ /**@brief Function for handling error message events from sd_rpc. * * @param[in] adapter The transport adapter. * @param[in] code Error code that the error message is associated with. * @param[in] message The error message that the callback is associated with. */ static void status_handler(adapter_t * adapter, sd_rpc_app_status_t code, const char * message) { printf("Status: %d, message: %s ", (uint32_t)code, message); fflush(stdout); } /**@brief Function for handling the log message events from sd_rpc. * * @param[in] adapter The transport adapter. * @param[in] severity Level of severity that the log message is associated with. * @param[in] message The log message that the callback is associated with. */ static void log_handler(adapter_t * adapter, sd_rpc_log_severity_t severity, const char * message) { switch (severity) { case SD_RPC_LOG_ERROR: printf("Error: %s ", message); fflush(stdout); break; case SD_RPC_LOG_WARNING: printf("Warning: %s ", message); fflush(stdout); break; case SD_RPC_LOG_INFO: printf("Info: %s ", message); fflush(stdout); break; default: printf("Log: %s ", message); fflush(stdout); break; } } /**@brief Function for initializing serial communication with the target nRF5 Bluetooth slave. * * @param[in] serial_port The serial port the target nRF5 device is connected to. * * @return The new transport adapter. */ static adapter_t * adapter_init(char * serial_port, uint32_t baud_rate) { physical_layer_t * phy; data_link_layer_t * data_link_layer; transport_layer_t * transport_layer; phy = sd_rpc_physical_layer_create_uart(serial_port, baud_rate, SD_RPC_FLOW_CONTROL_NONE, SD_RPC_PARITY_NONE); data_link_layer = sd_rpc_data_link_layer_create_bt_three_wire(phy, 100); transport_layer = sd_rpc_transport_layer_create(data_link_layer, 100); return sd_rpc_adapter_create(transport_layer); } /**@brief Function for converting a BLE address to a string. * * @param[in] address Bluetooth Low Energy address. * @param[out] string_buffer The serial port the target nRF5 device is connected to. */ static void ble_address_to_string_convert(ble_gap_addr_t address, uint8_t * string_buffer) { const int address_length = 6; char temp_str[3]; for (int i = address_length - 1; i >= 0; --i) { sprintf(temp_str, "%02X", address.addr[i]); strcat((char *)string_buffer, temp_str); } } /** * @brief Parses advertisement data, providing length and location of the field in case * matching data is found. * * @param[in] Type of data to be looked for in advertisement data. * @param[in] Advertisement report length and pointer to report. * @param[out] If data type requested is found in the data report, type data length and * pointer to data will be populated here. * * @retval NRF_SUCCESS if the data type is found in the report. * @retval NRF_ERROR_NOT_FOUND if the data type could not be found. */ static uint32_t adv_report_parse(uint8_t type, data_t * p_advdata, data_t * p_typedata) { uint32_t index = 0; uint8_t * p_data; p_data = p_advdata->p_data; while (index < p_advdata->data_len) { uint8_t field_length = p_data[index]; uint8_t field_type = p_data[index + 1]; if (field_type == type) { p_typedata->p_data = &p_data[index + 2]; p_typedata->data_len = field_length - 1; return NRF_SUCCESS; } index += field_length + 1; } return NRF_ERROR_NOT_FOUND; } /**@brief Function for searching a given name in the advertisement packets. * * @details Use this function to parse received advertising data and to find a given * name in them either as 'complete_local_name' or as 'short_local_name'. * * @param[in] p_adv_report advertising data to parse. * @param[in] name_to_find name to search. * @return true if the given name was found, false otherwise. */ static bool find_adv_name(const ble_gap_evt_adv_report_t *p_adv_report, const char * name_to_find) { uint32_t err_code; data_t adv_data; data_t dev_name; // Initialize advertisement report for parsing #if NRF_SD_BLE_API >= 6 adv_data.p_data = (uint8_t *)p_adv_report->data.p_data; adv_data.data_len = p_adv_report->data.len; #else adv_data.p_data = (uint8_t *)p_adv_report->data; adv_data.data_len = p_adv_report->dlen; #endif //search for advertising names err_code = adv_report_parse(BLE_GAP_AD_TYPE_COMPLETE_LOCAL_NAME, &adv_data, &dev_name); if (err_code == NRF_SUCCESS) { if (memcmp(name_to_find, dev_name.p_data, dev_name.data_len )== 0) { return true; } } else { // Look for the short local name if it was not found as complete err_code = adv_report_parse(BLE_GAP_AD_TYPE_SHORT_LOCAL_NAME, &adv_data, &dev_name); if (err_code != NRF_SUCCESS) { return false; } if (memcmp(name_to_find, dev_name.p_data, dev_name.data_len )== 0) { return true; } } return false; } /**@brief Function for initializing the BLE stack. * * @return NRF_SUCCESS on success, otherwise an error code. */ static uint32_t ble_stack_init() { uint32_t err_code; uint32_t * app_ram_base = NULL; #if NRF_SD_BLE_API <= 3 ble_enable_params_t ble_enable_params; memset(&ble_enable_params, 0, sizeof(ble_enable_params)); #endif #if NRF_SD_BLE_API == 3 ble_enable_params.gatt_enable_params.att_mtu = GATT_MTU_SIZE_DEFAULT; #elif NRF_SD_BLE_API < 3 ble_enable_params.gatts_enable_params.attr_tab_size = BLE_GATTS_ATTR_TAB_SIZE_DEFAULT; ble_enable_params.gatts_enable_params.service_changed = false; ble_enable_params.common_enable_params.p_conn_bw_counts = NULL; ble_enable_params.common_enable_params.vs_uuid_count = 1; #endif #if NRF_SD_BLE_API <= 3 ble_enable_params.gap_enable_params.periph_conn_count = 1; ble_enable_params.gap_enable_params.central_conn_count = 1; ble_enable_params.gap_enable_params.central_sec_count = 1; err_code = sd_ble_enable(m_adapter, &ble_enable_params, app_ram_base); #else err_code = sd_ble_enable(m_adapter, app_ram_base); #endif switch (err_code) { case NRF_SUCCESS: break; case NRF_ERROR_INVALID_STATE: printf("BLE stack already enabled "); fflush(stdout); break; default: printf("Failed to enable BLE stack. Error code: %d ", err_code); fflush(stdout); break; } return err_code; } #if NRF_SD_BLE_API < 5 /**@brief Set BLE option for the BLE role and connection bandwidth. * * @return NRF_SUCCESS on option set successfully, otherwise an error code. */ static uint32_t ble_options_set() { #if NRF_SD_BLE_API <= 3 ble_opt_t opt; ble_common_opt_t common_opt; common_opt.conn_bw.role = BLE_GAP_ROLE_CENTRAL; common_opt.conn_bw.conn_bw.conn_bw_rx = BLE_CONN_BW_HIGH; common_opt.conn_bw.conn_bw.conn_bw_tx = BLE_CONN_BW_HIGH; opt.common_opt = common_opt; return sd_ble_opt_set(m_adapter, BLE_COMMON_OPT_CONN_BW, &opt); #else return NRF_ERROR_NOT_SUPPORTED; #endif } #endif #if NRF_SD_BLE_API >= 5 /**@brief Function for setting configuration for the BLE stack. * * @return NRF_SUCCESS on success, otherwise an error code. */ static uint32_t ble_cfg_set(uint8_t conn_cfg_tag) { const uint32_t ram_start = 0; // Value is not used by ble-driver uint32_t error_code; ble_cfg_t ble_cfg; // Configure the connection roles. memset(&ble_cfg, 0, sizeof(ble_cfg)); #if NRF_SD_BLE_API >= 6 ble_cfg.gap_cfg.role_count_cfg.adv_set_count = BLE_GAP_ADV_SET_COUNT_DEFAULT; #endif ble_cfg.gap_cfg.role_count_cfg.periph_role_count = 0; ble_cfg.gap_cfg.role_count_cfg.central_role_count = 1; ble_cfg.gap_cfg.role_count_cfg.central_sec_count = 0; error_code = sd_ble_cfg_set(m_adapter, BLE_GAP_CFG_ROLE_COUNT, &ble_cfg, ram_start); if (error_code != NRF_SUCCESS) { printf("sd_ble_cfg_set() failed when attempting to set BLE_GAP_CFG_ROLE_COUNT. Error code: 0x%02X ", error_code); fflush(stdout); return error_code; } memset(&ble_cfg, 0x00, sizeof(ble_cfg)); ble_cfg.conn_cfg.conn_cfg_tag = conn_cfg_tag; ble_cfg.conn_cfg.params.gatt_conn_cfg.att_mtu = 150; error_code = sd_ble_cfg_set(m_adapter, BLE_CONN_CFG_GATT, &ble_cfg, ram_start); if (error_code != NRF_SUCCESS) { printf("sd_ble_cfg_set() failed when attempting to set BLE_CONN_CFG_GATT. Error code: 0x%02X ", error_code); fflush(stdout); return error_code; } return NRF_SUCCESS; } #endif /**@brief Start scanning (GAP Discovery procedure, Observer Procedure). * * * @return NRF_SUCCESS on successfully initiating scanning procedure, otherwise an error code. */ static uint32_t scan_start() { #if NRF_SD_BLE_API >= 6 m_adv_report_buffer.p_data = mp_data; m_adv_report_buffer.len = sizeof(mp_data); #endif uint32_t error_code = sd_ble_gap_scan_start(m_adapter, &m_scan_param #if NRF_SD_BLE_API >= 6 , &m_adv_report_buffer #endif ); if (error_code != NRF_SUCCESS) { printf("Scan start failed with error code: %d ", error_code); fflush(stdout); } else { printf("Scan started "); fflush(stdout); } return error_code; } /**@brief Function called upon connecting to BLE peripheral. * * @details Initiates primary service discovery. * * @return NRF_SUCCESS on success, otherwise an error code. */ static uint32_t service_discovery_start() { uint32_t err_code; uint16_t start_handle = 0x01; ble_uuid_t srvc_uuid; printf("Discovering primary services "); fflush(stdout); srvc_uuid.type = BLE_UUID_TYPE_BLE; srvc_uuid.uuid = BLE_UUID_HEART_RATE_SERVICE; // Initiate procedure to find the primary BLE_UUID_HEART_RATE_SERVICE. err_code = sd_ble_gattc_primary_services_discover(m_adapter, m_connection_handle, start_handle, &srvc_uuid); if (err_code != NRF_SUCCESS) { printf("Failed to initiate or continue a GATT Primary Service Discovery procedure "); fflush(stdout); } return err_code; } /**@brief Function called upon discovering a BLE peripheral's primary service(s). * * @details Initiates service's (m_service) characteristic discovery. * * @return NRF_SUCCESS on success, otherwise an error code. */ static uint32_t char_discovery_start() { ble_gattc_handle_range_t handle_range; printf("Discovering characteristics "); fflush(stdout); handle_range.start_handle = m_service_start_handle; handle_range.end_handle = m_service_end_handle; return sd_ble_gattc_characteristics_discover(m_adapter, m_connection_handle, &handle_range); } /**@brief Function called upon discovering service's characteristics. * * @details Initiates heart rate monitor (m_hrm_char_handle) characteristic's descriptor discovery. * * @return NRF_SUCCESS on success, otherwise an error code. */ static uint32_t descr_discovery_start() { ble_gattc_handle_range_t handle_range; printf("Discovering characteristic's descriptors "); fflush(stdout); if (m_hrm_char_handle == 0) { printf("No heart rate measurement characteristic handle found "); fflush(stdout); return NRF_ERROR_INVALID_STATE; } handle_range.start_handle = m_hrm_char_handle; handle_range.end_handle = m_service_end_handle; return sd_ble_gattc_descriptors_discover(m_adapter, m_connection_handle, &handle_range); } /**@brief Function that write's the HRM characteristic's CCCD. * * * @return NRF_SUCCESS on success, otherwise an error code. */ static uint32_t hrm_cccd_set(uint8_t value) { ble_gattc_write_params_t write_params; uint8_t cccd_value[2] = {value, 0}; printf("Setting HRM CCCD "); fflush(stdout); if (m_hrm_cccd_handle == 0) { printf("Error. No CCCD handle has been found "); fflush(stdout); return NRF_ERROR_INVALID_STATE; } write_params.handle = m_hrm_cccd_handle; write_params.len = 2; write_params.p_value = cccd_value; write_params.write_op = BLE_GATT_OP_WRITE_REQ; write_params.offset = 0; return sd_ble_gattc_write(m_adapter, m_connection_handle, &write_params); } /** Event functions */ /**@brief Function called on BLE_GAP_EVT_CONNECTED event. * * @details Update connection state and proceed to discovering the peer's GATT services. * * @param[in] p_ble_gap_evt GAP event. */ static void on_connected(const ble_gap_evt_t * const p_ble_gap_evt) { printf("Connection established "); fflush(stdout); m_connected_devices++; m_connection_handle = p_ble_gap_evt->conn_handle; m_connection_is_in_progress = false; service_discovery_start(); } /**@brief Function called on BLE_GAP_EVT_ADV_REPORT event. * * @details Create a connection if received advertising packet corresponds to desired BLE device. * * @param[in] p_ble_gap_evt Advertising Report Event. */ static void on_adv_report(const ble_gap_evt_t * const p_ble_gap_evt) { uint32_t err_code; uint8_t str[STRING_BUFFER_SIZE] = {0}; // Log the Bluetooth device address of advertisement packet received. ble_address_to_string_convert(p_ble_gap_evt->params.adv_report.peer_addr, str); printf("Received advertisement report with device address: 0x%s ", str); fflush(stdout); if (find_adv_name(&p_ble_gap_evt->params.adv_report, TARGET_DEV_NAME)) { if (m_connected_devices >= MAX_PEER_COUNT || m_connection_is_in_progress) { return; } err_code = sd_ble_gap_connect(m_adapter, &(p_ble_gap_evt->params.adv_report.peer_addr), &m_scan_param, &m_connection_param #if NRF_SD_BLE_API >= 5 , m_config_id #endif ); if (err_code != NRF_SUCCESS) { printf("Connection Request Failed, reason %d ", err_code); fflush(stdout); return; } m_connection_is_in_progress = true; } #if NRF_SD_BLE_API >= 6 else { err_code = sd_ble_gap_scan_start(m_adapter, NULL, &m_adv_report_buffer); if (err_code != NRF_SUCCESS) { printf("Scan start failed with error code: %d ", err_code); fflush(stdout); } else { printf("Scan started "); fflush(stdout); } } #endif } /**@brief Function called on BLE_GAP_EVT_TIMEOUT event. * * @param[in] ble_gap_evt_t Timeout Event. */ static void on_timeout(const ble_gap_evt_t * const p_ble_gap_evt) { if (p_ble_gap_evt->params.timeout.src == BLE_GAP_TIMEOUT_SRC_CONN) { m_connection_is_in_progress = false; } else if (p_ble_gap_evt->params.timeout.src == BLE_GAP_TIMEOUT_SRC_SCAN) { scan_start(); } } /**@brief Function called on BLE_GATTC_EVT_PRIM_SRVC_DISC_RSP event. * * @details Update service state and proceed to discovering the service's GATT characteristics. * * @param[in] p_ble_gattc_evt Primary Service Discovery Response Event. */ static void on_service_discovery_response(const ble_gattc_evt_t * const p_ble_gattc_evt) { int count; int service_index; const ble_gattc_service_t * service; printf("Received service discovery response "); fflush(stdout); if (p_ble_gattc_evt->gatt_status != NRF_SUCCESS) { printf("Service discovery failed. Error code 0x%X ", p_ble_gattc_evt->gatt_status); fflush(stdout); return; } count = p_ble_gattc_evt->params.prim_srvc_disc_rsp.count; if (count == 0) { printf("Service not found "); fflush(stdout); return; } if (count > 1) { printf("Warning, discovered multiple primary services. Ignoring all but the first "); } service_index = 0; /* We expect to discover only the Heart Rate service as requested. */ service = &(p_ble_gattc_evt->params.prim_srvc_disc_rsp.services[service_index]); if (service->uuid.uuid != BLE_UUID_HEART_RATE_SERVICE) { printf("Unknown service discovered with UUID: 0x%04X ", service->uuid.uuid); fflush(stdout); return; } m_service_start_handle = service->handle_range.start_handle; m_service_end_handle = service->handle_range.end_handle; printf("Discovered heart rate service. UUID: 0x%04X, " "start handle: 0x%04X, end handle: 0x%04X ", service->uuid.uuid, m_service_start_handle, m_service_end_handle); fflush(stdout); char_discovery_start(); } /**@brief Function called on BLE_GATTC_EVT_CHAR_DISC_RSP event. * * @details Update characteristic state and proceed to discovering the characteristicss descriptors. * * @param[in] p_ble_gattc_evt Characteristic Discovery Response Event. */ static void on_characteristic_discovery_response(const ble_gattc_evt_t * const p_ble_gattc_evt) { int count = p_ble_gattc_evt->params.char_disc_rsp.count; if (p_ble_gattc_evt->gatt_status != NRF_SUCCESS) { printf("Characteristic discovery failed. Error code 0x%X ", p_ble_gattc_evt->gatt_status); fflush(stdout); return; } printf("Received characteristic discovery response, characteristics count: %d ", count); fflush(stdout); for (int i = 0; i < count; i++) { printf("Characteristic handle: 0x%04X, UUID: 0x%04X ", p_ble_gattc_evt->params.char_disc_rsp.chars[i].handle_decl, p_ble_gattc_evt->params.char_disc_rsp.chars[i].uuid.uuid); fflush(stdout); if (p_ble_gattc_evt->params.char_disc_rsp.chars[i].uuid.uuid == BLE_UUID_HEART_RATE_MEASUREMENT_CHAR) { m_hrm_char_handle = p_ble_gattc_evt->params.char_disc_rsp.chars[i].handle_decl; } } descr_discovery_start(); } /**@brief Function called on BLE_GATTC_EVT_DESC_DISC_RSP event. * * @details Update CCCD descriptor state and proceed to prompting user to toggle notifications. * * @param[in] p_ble_gattc_evt Descriptor Discovery Response Event. */ static void on_descriptor_discovery_response(const ble_gattc_evt_t * const p_ble_gattc_evt) { int count = p_ble_gattc_evt->params.desc_disc_rsp.count; if (p_ble_gattc_evt->gatt_status != NRF_SUCCESS) { printf("Descriptor discovery failed. Error code 0x%X ", p_ble_gattc_evt->gatt_status); fflush(stdout); return; } printf("Received descriptor discovery response, descriptor count: %d ", count); fflush(stdout); for (int i = 0; i < count; i++) { printf("Descriptor handle: 0x%04X, UUID: 0x%04X ", p_ble_gattc_evt->params.desc_disc_rsp.descs[i].handle, p_ble_gattc_evt->params.desc_disc_rsp.descs[i].uuid.uuid); fflush(stdout); if (p_ble_gattc_evt->params.desc_disc_rsp.descs[i].uuid.uuid == BLE_UUID_CCCD) { m_hrm_cccd_handle = p_ble_gattc_evt->params.desc_disc_rsp.descs[i].handle; printf("Press enter to toggle notifications on the HRM characteristic "); fflush(stdout); } } } /**@brief Function called on BLE_GATTC_EVT_WRITE_RSP event. * * @param[in] p_ble_gattc_evt Write Response Event. */ static void on_write_response(const ble_gattc_evt_t * const p_ble_gattc_evt) { printf("Received write response. "); fflush(stdout); if (p_ble_gattc_evt->gatt_status != NRF_SUCCESS) { printf("Error. Write operation failed. Error code 0x%X ", p_ble_gattc_evt->gatt_status); fflush(stdout); } } /**@brief Function called on BLE_GATTC_EVT_HVX event. * * @details Logs the received heart rate measurement. * * @param[in] p_ble_gattc_evt Handle Value Notification/Indication Event. */ static void on_hvx(const ble_gattc_evt_t * const p_ble_gattc_evt) { if (p_ble_gattc_evt->params.hvx.handle >= m_hrm_char_handle || p_ble_gattc_evt->params.hvx.handle <= m_hrm_cccd_handle) // Heart rate measurement. { // We know the heart rate reading is encoded as 2 bytes [flag, value]. printf("Received heart rate measurement: %d ", p_ble_gattc_evt->params.hvx.data[1]); } else // Unknown data. { printf("Un-parsed data received on handle: %04X ", p_ble_gattc_evt->params.hvx.handle); } fflush(stdout); } /**@brief Function called on BLE_GAP_EVT_CONN_PARAM_UPDATE_REQUEST event. * * @details Update GAP connection parameters. * * @param[in] p_ble_gap_evt Connection Parameter Update Event. */ static void on_conn_params_update_request(const ble_gap_evt_t * const p_ble_gap_evt) { uint32_t err_code = sd_ble_gap_conn_param_update(m_adapter, m_connection_handle, &(p_ble_gap_evt-> params.conn_param_update_request.conn_params)); if (err_code != NRF_SUCCESS) { printf("Conn params update failed, err_code %d ", err_code); fflush(stdout); } } #if NRF_SD_BLE_API >= 3 /**@brief Function called on BLE_GATTS_EVT_EXCHANGE_MTU_REQUEST event. * * @details Replies to an ATT_MTU exchange request by sending an Exchange MTU Response to the client. * * @param[in] p_ble_gatts_evt Exchange MTU Request Event. */ static void on_exchange_mtu_request(const ble_gatts_evt_t * const p_ble_gatts_evt) { uint32_t err_code = sd_ble_gatts_exchange_mtu_reply( m_adapter, m_connection_handle, #if NRF_SD_BLE_API < 5 GATT_MTU_SIZE_DEFAULT); #else BLE_GATT_ATT_MTU_DEFAULT); #endif if (err_code != NRF_SUCCESS) { printf("MTU exchange request reply failed, err_code %d ", err_code); fflush(stdout); } } /**@brief Function called on BLE_GATTC_EVT_EXCHANGE_MTU_RSP event. * * @details Logs the new BLE server RX MTU size. * * @param[in] p_ble_gattc_evt Exchange MTU Response Event. */ static void on_exchange_mtu_response(const ble_gattc_evt_t * const p_ble_gattc_evt) { uint16_t server_rx_mtu = p_ble_gattc_evt->params.exchange_mtu_rsp.server_rx_mtu; printf("MTU response received. New ATT_MTU is %d ", server_rx_mtu); fflush(stdout); } #endif static void on_conn_data_length_update_request(const ble_gattc_evt_t * const p_ble_gattc_evt) { printf("BLE_GAP_EVT_DATA_LENGTH_UPDATE_REQUEST received "); ble_gap_data_length_params_t const dlp = { .max_rx_octets = 27, .max_tx_octets = 27, .max_rx_time_us = BLE_GAP_DATA_LENGTH_AUTO, .max_tx_time_us = BLE_GAP_DATA_LENGTH_AUTO, }; ble_gap_data_length_limitation_t dll = { 0 }; uint32_t err_code = sd_ble_gap_data_length_update(m_adapter, m_connection_handle, &dlp, &dll); if (err_code != NRF_SUCCESS) { printf("sd_ble_gap_data_length_update failed, err_code %d ", err_code); } } /** Event dispatcher */ /**@brief Function for handling the Application's BLE Stack events. * * @param[in] adapter The transport adapter. * @param[in] p_ble_evt Bluetooth stack event. */ static void ble_evt_dispatch(adapter_t * adapter, ble_evt_t * p_ble_evt) { if (p_ble_evt == NULL) { printf("Received an empty BLE event "); fflush(stdout); return; } switch (p_ble_evt->header.evt_id) { case BLE_GAP_EVT_CONNECTED: on_connected(&(p_ble_evt->evt.gap_evt)); break; case BLE_GAP_EVT_DISCONNECTED: printf("Disconnected, reason: 0x%02X ", p_ble_evt->evt.gap_evt.params.disconnected.reason); fflush(stdout); m_connected_devices--; m_connection_handle = 0; break; case BLE_GAP_EVT_ADV_REPORT: on_adv_report(&(p_ble_evt->evt.gap_evt)); break; case BLE_GAP_EVT_TIMEOUT: on_timeout(&(p_ble_evt->evt.gap_evt)); break; case BLE_GATTC_EVT_PRIM_SRVC_DISC_RSP: on_service_discovery_response(&(p_ble_evt->evt.gattc_evt)); break; case BLE_GATTC_EVT_CHAR_DISC_RSP: on_characteristic_discovery_response(&(p_ble_evt->evt.gattc_evt)); break; case BLE_GATTC_EVT_DESC_DISC_RSP: on_descriptor_discovery_response(&(p_ble_evt->evt.gattc_evt)); break; case BLE_GATTC_EVT_WRITE_RSP: on_write_response(&(p_ble_evt->evt.gattc_evt)); break; case BLE_GATTC_EVT_HVX: on_hvx(&(p_ble_evt->evt.gattc_evt)); break; case BLE_GAP_EVT_CONN_PARAM_UPDATE_REQUEST: on_conn_params_update_request(&(p_ble_evt->evt.gap_evt)); break; case BLE_GAP_EVT_DATA_LENGTH_UPDATE_REQUEST: on_conn_data_length_update_request(&(p_ble_evt->evt.gattc_evt)); break; case BLE_GAP_EVT_DATA_LENGTH_UPDATE: printf("LL Data Channel PDU payload length updated "); break; case BLE_GAP_EVT_CONN_PARAM_UPDATE: printf("BLE_GAP_EVT_CONN_PARAM_UPDATE: max %d and min %d ", p_ble_evt->evt.gap_evt.params.conn_param_update.conn_params.max_conn_interval*UNIT_1_25_MS / 1000, p_ble_evt->evt.gap_evt.params.conn_param_update.conn_params.min_conn_interval*UNIT_1_25_MS / 1000); break; #if NRF_SD_BLE_API >= 3 case BLE_GATTS_EVT_EXCHANGE_MTU_REQUEST: on_exchange_mtu_request(&(p_ble_evt->evt.gatts_evt)); break; case BLE_GATTC_EVT_EXCHANGE_MTU_RSP: on_exchange_mtu_response(&(p_ble_evt->evt.gattc_evt)); break; #endif default: printf("Received an un-handled event with ID: %d ", p_ble_evt->header.evt_id); fflush(stdout); break; } } /** Main */ /**@brief Function for application main entry. * * @param[in] argc Number of arguments (program expects 0 or 1 arguments). * @param[in] argv The serial port and baud rate of the target nRF5 device (Optional). */ int main(int argc, char * argv[]) { uint32_t error_code; char * serial_port = DEFAULT_UART_PORT_NAME; uint32_t baud_rate = DEFAULT_BAUD_RATE; uint8_t cccd_value = 0; if (argc > 2) { if (strcmp(argv[2], "1000000") == 0) { baud_rate = 1000000; } else if (strcmp(argv[2], "115200") == 0) { baud_rate = 115200; } else { printf("Supported baud rate values are: 115200, 1000000 "); fflush(stdout); } } if (argc > 1) { serial_port = argv[1]; } printf("Serial port used: %s ", serial_port); printf("Baud rate used: %d ", baud_rate); fflush(stdout); m_adapter = adapter_init(serial_port, baud_rate); sd_rpc_log_handler_severity_filter_set(m_adapter, SD_RPC_LOG_INFO); error_code = sd_rpc_open(m_adapter, status_handler, ble_evt_dispatch, log_handler); if (error_code != NRF_SUCCESS) { printf("Failed to open nRF BLE Driver. Error code: 0x%02X ", error_code); fflush(stdout); return error_code; } #if NRF_SD_BLE_API >= 5 ble_cfg_set(m_config_id); #endif error_code = ble_stack_init(); if (error_code != NRF_SUCCESS) { return error_code; } #if NRF_SD_BLE_API < 5 error_code = ble_options_set(); if (error_code != NRF_SUCCESS) { return error_code; } #endif error_code = scan_start(); if (error_code != NRF_SUCCESS) { return error_code; } // Endlessly loop. for (;;) { char c = (char)getchar(); if (c == 'q' || c == 'Q') { error_code = sd_rpc_close(m_adapter); if (error_code != NRF_SUCCESS) { printf("Failed to close nRF BLE Driver. Error code: 0x%02X ", error_code); fflush(stdout); return error_code; } printf("Closed "); fflush(stdout); return NRF_SUCCESS; } // Toggle notifications on the HRM characteristic every time user input is received. cccd_value ^= BLE_CCCD_NOTIFY; hrm_cccd_set(cccd_value); } } 3) You can find the documentation for the example here .

Sigurd · Answer

Hi Chencheng, 
 The connectivity firmware is compiled with NRF_SDH_BLE_GAP_DATA_LENGTH (sdk_config.h) set to 27. That is the reason why I set max_rx_octets and max_tx_octets to 27 in the code I posted. You might be able to use higher values if you compile the connectivity firmware yourself with NRF_SDH_BLE_GAP_DATA_LENGTH set to a higher value, but I cannot guarantee that the rest of the serialization library will support that change.

Disconnection between "ble_app_hrs" example in SDK 15.2.0 and "heart_rate_collector" example with pc-ble-driver (c/c++)

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