ESP32蓝牙的Gatt Client的例子演练

时间:2022-07-23
本文章向大家介绍ESP32蓝牙的Gatt Client的例子演练,主要内容包括其使用实例、应用技巧、基本知识点总结和需要注意事项,具有一定的参考价值,需要的朋友可以参考一下。

翻译内容仅供参考,原文链接: https://github.com/espressif/esp-idf/blob/dd8db6621/examples/bluetooth/bluedroid/ble/gatt_client/tutorial/Gatt_Client_Example_Walkthrough.md

#include <stdint.h>
#include <string.h>
#include <stdbool.h>
#include <stdio.h>
#include "nvs.h"
#include "nvs_flash.h"
#include "controller.h"

#include "bt.h"
#include "esp_gap_ble_api.h"
#include "esp_gattc_api.h"
#include "esp_gatt_defs.h"
#include "esp_bt_main.h"
#include "esp_gatt_common_api.h"
void app_main()
{
    // Initialize NVS.
    esp_err_t ret = nvs_flash_init();
    if (ret == ESP_ERR_NVS_NO_FREE_PAGES || ret == ESP_ERR_NVS_NEW_VERSION_FOUND) {
        ESP_ERROR_CHECK(nvs_flash_erase());
        ret = nvs_flash_init();
    }
    ESP_ERROR_CHECK( ret );

    esp_bt_controller_config_t bt_cfg = BT_CONTROLLER_INIT_CONFIG_DEFAULT();
    ret = esp_bt_controller_init(&bt_cfg);
    if (ret) {
        ESP_LOGE(GATTC_TAG, "%s initialize controller failed, error code = %xn", __func__, ret);
        return;
    }

    ret = esp_bt_controller_enable(ESP_BT_MODE_BLE);
    if (ret) {
        ESP_LOGE(GATTC_TAG, "%s enable controller failed, error code = %xn", __func__, ret);
        return;
    }

    ret = esp_bluedroid_init();
    if (ret) {
        ESP_LOGE(GATTC_TAG, "%s init bluetooth failed, error code = %xn", __func__, ret);
        return;
    }

    ret = esp_bluedroid_enable();
    if (ret) {
        ESP_LOGE(GATTC_TAG, "%s enable bluetooth failed, error code = %xn", __func__, ret);
        return;
    }

    //register the  callback function to the gap module
    ret = esp_ble_gap_register_callback(esp_gap_cb);
    if (ret){
        ESP_LOGE(GATTC_TAG, "%s gap register failed, error code = %xn", __func__, ret);
        return;
    }

    //register the callback function to the gattc module
    ret = esp_ble_gattc_register_callback(esp_gattc_cb);
    if(ret){
        ESP_LOGE(GATTC_TAG, "%s gattc register failed, error code = %xn", __func__, ret);
        return;
    }

    ret = esp_ble_gattc_app_register(PROFILE_A_APP_ID);
    if (ret){
        ESP_LOGE(GATTC_TAG, "%s gattc app register failed, error code = %xn", __func__, ret);
    }

    esp_err_t local_mtu_ret = esp_ble_gatt_set_local_mtu(500);
    if (local_mtu_ret){
        ESP_LOGE(GATTC_TAG, "set local  MTU failed, error code = %x", local_mtu_ret);
    }

}
esp_err_t ret = nvs_flash_init();
if (ret == ESP_ERR_NVS_NO_FREE_PAGES || ret == ESP_ERR_NVS_NEW_VERSION_FOUND) {
    ESP_ERROR_CHECK(nvs_flash_erase());
    ret = nvs_flash_init();
}
ESP_ERROR_CHECK( ret );
esp_bt_controller_config_t bt_cfg = BT_CONTROLLER_INIT_CONFIG_DEFAULT();
ret = esp_bt_controller_init(&bt_cfg);
ret = esp_bt_controller_enable(ESP_BT_MODE_BLE);
ret = esp_bluedroid_init();
ret = esp_bluedroid_enable();
    //register the  callback function to the gap module
    ret = esp_ble_gap_register_callback(esp_gap_cb);

    //register the callback function to the gattc module
    ret = esp_ble_gattc_register_callback(esp_gattc_cb);

    ret = esp_ble_gattc_app_register(PROFILE_A_APP_ID);

    esp_err_t local_mtu_ret = esp_ble_gatt_set_local_mtu(500);
    if (local_mtu_ret){
        ESP_LOGE(GATTC_TAG, "set local  MTU failed, error code = %x", local_mtu_ret);
    }
esp_ble_gap_register_callback();
esp_ble_gattc_register_callback();
struct gattc_profile_inst {
    esp_gattc_cb_t gattc_cb;
    uint16_t gattc_if;
    uint16_t app_id;
    uint16_t conn_id;
    uint16_t service_start_handle;
    uint16_t service_end_handle;
    uint16_t char_handle;
    esp_bd_addr_t remote_bda;
};
#define PROFILE_NUM 1
#define PROFILE_A_APP_ID 0
/* One gatt-based profile one app_id and one gattc_if, this array will store the gattc_if returned by ESP_GATTS_REG_EVT */
static struct gattc_profile_inst gl_profile_tab[PROFILE_NUM] = {
		[PROFILE_A_APP_ID] = {.gattc_cb = gattc_profile_event_handler,
								  .gattc_if = ESP_GATT_IF_NONE, /* Not get the gatt_if, so initial is ESP_GATT_IF_NONE */
    },
};
static void esp_gattc_cb(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_if, esp_ble_gattc_cb_param_t *param)
{
    ESP_LOGI(GATTC_TAG, "EVT %d, gattc if %d", event, gattc_if);

    /* If event is register event, store the gattc_if for each profile */
    if (event == ESP_GATTC_REG_EVT) {
        if (param->reg.status == ESP_GATT_OK) {
            gl_profile_tab[param->reg.app_id].gattc_if = gattc_if;
        } else {
            ESP_LOGI(GATTC_TAG, "reg app failed, app_id %04x, status %d",
                    param->reg.app_id,
                    param->reg.status);
            return;
        }
    }
…
…
/* If the gattc_if equal to profile A, call profile A cb handler,
     * so here call each profile's callback */
    do {
        int idx;
        for (idx = 0; idx < PROFILE_NUM; idx++) {
            if (gattc_if == ESP_GATT_IF_NONE || /* ESP_GATT_IF_NONE, not specify a certain gatt_if, need to call every profile cb function */
                    gattc_if == gl_profile_tab[idx].gattc_if) {
                if (gl_profile_tab[idx].gattc_cb) {
                    gl_profile_tab[idx].gattc_cb(event, gattc_if, param);
                }
            }
        }
    } while (0);
}
/// Ble scan parameters
typedef struct {
    esp_ble_scan_type_t     scan_type;              /*!< Scan type */
    esp_ble_addr_type_t     own_addr_type;          /*!< Owner address type */
    esp_ble_scan_filter_t   scan_filter_policy;     /*!< Scan filter policy */
    uint16_t                scan_interval;          /*!< Scan interval. This is defined as the time interval from when the Controller started its last LE scan until it begins the subsequent LE scan.*/ 
    //Range: 0x0004 to 0x4000 
    //Default: 0x0010 (10 ms)
    //Time = N * 0.625 msec
    //Time Range: 2.5 msec to 10.24	seconds
    uint16_t                scan_window;            /*!< Scan window. The duration of the LE scan. LE_Scan_Window shall be less than or equal to LE_Scan_Interval*/
    //Range: 0x0004 to 0x4000                                                   	 //Default: 0x0010 (10 ms)
    //Time = N * 0.625 msec
    //Time Range: 2.5 msec to 10240 msec
} esp_ble_scan_params_t;
static esp_ble_scan_params_t ble_scan_params = {
    .scan_type              = BLE_SCAN_TYPE_ACTIVE,
    .own_addr_type          = BLE_ADDR_TYPE_PUBLIC,
    .scan_filter_policy     = BLE_SCAN_FILTER_ALLOW_ALL,
    .scan_interval          = 0x50,
    .scan_window            = 0x30
};
case ESP_GATTC_REG_EVT:
        ESP_LOGI(GATTC_TAG, "REG_EVT");
        esp_err_t scan_ret = esp_ble_gap_set_scan_params(&ble_scan_params);
        if (scan_ret){
            ESP_LOGE(GATTC_TAG, "set scan params error, error code = %x", scan_ret);
        }
        break;
    case ESP_GAP_BLE_SCAN_PARAM_SET_COMPLETE_EVT: {
        //the unit of the duration is second
        uint32_t duration = 30;
        esp_ble_gap_start_scanning(duration);
        break;
        }
 /**
     * @brief ESP_GAP_BLE_SCAN_RESULT_EVT
     */
    struct ble_scan_result_evt_param {
        esp_gap_search_evt_t search_evt;            /*!< Search event type */
        esp_bd_addr_t bda;                          /*!< Bluetooth device address which has been searched */
        esp_bt_dev_type_t dev_type;                 /*!< Device type */
        esp_ble_addr_type_t ble_addr_type;          /*!< Ble device address type */
        esp_ble_evt_type_t ble_evt_type;            /*!< Ble scan result event type */
        int rssi;                                   /*!< Searched device's RSSI */
        uint8_t  ble_adv[ESP_BLE_ADV_DATA_LEN_MAX + ESP_BLE_SCAN_RSP_DATA_LEN_MAX]; /*!< Received EIR */
        int flag;                                   /*!< Advertising data flag bit */
        int num_resps;                              /*!< Scan result number */
        uint8_t adv_data_len;                       /*!< Adv data length */
        uint8_t scan_rsp_len;                       /*!< Scan response length */
    } scan_rst;                                     /*!< Event parameter of ESP_GAP_BLE_SCAN_RESULT_EVT */
/// Sub Event of ESP_GAP_BLE_SCAN_RESULT_EVT
typedef enum {
    ESP_GAP_SEARCH_INQ_RES_EVT             = 0,      /*!< Inquiry result for a peer device. */
    ESP_GAP_SEARCH_INQ_CMPL_EVT            = 1,      /*!< Inquiry complete. */
    ESP_GAP_SEARCH_DISC_RES_EVT            = 2,      /*!< Discovery result for a peer device. */
    ESP_GAP_SEARCH_DISC_BLE_RES_EVT        = 3,      /*!< Discovery result for BLE GATT based service on a peer device. */
    ESP_GAP_SEARCH_DISC_CMPL_EVT           = 4,      /*!< Discovery complete. */
    ESP_GAP_SEARCH_DI_DISC_CMPL_EVT        = 5,      /*!< Discovery complete. */
    ESP_GAP_SEARCH_SEARCH_CANCEL_CMPL_EVT  = 6,      /*!< Search cancelled */
} esp_gap_search_evt_t;
      case ESP_GAP_BLE_SCAN_RESULT_EVT: {
        esp_ble_gap_cb_param_t *scan_result = (esp_ble_gap_cb_param_t *)param;
        switch (scan_result->scan_rst.search_evt) {
	        case ESP_GAP_SEARCH_INQ_RES_EVT:
		        esp_log_buffer_hex(GATTC_TAG, scan_result->scan_rst.bda, 6);
		        ESP_LOGI(GATTC_TAG, "searched Adv Data Len %d, Scan Response Len %d", scan_result->scan_rst.adv_data_len, scan_result->scan_rst.scan_rsp_len);
		        adv_name = esp_ble_resolve_adv_data(scan_result->scan_rst.ble_adv, ESP_BLE_AD_TYPE_NAME_CMPL, &adv_name_len);
		        ESP_LOGI(GATTC_TAG, "searched Device Name Len %d", adv_name_len);
		        esp_log_buffer_char(GATTC_TAG, adv_name, adv_name_len);
		        ESP_LOGI(GATTC_TAG, "n");
		        if (adv_name != NULL) {
			        if (strlen(remote_device_name) == adv_name_len && strncmp((char *)adv_name, remote_device_name, adv_name_len) == 0) {
                    ESP_LOGI(GATTC_TAG, "searched device %sn", remote_device_name);
                    if (connect == false) {
                        connect = true;
                        ESP_LOGI(GATTC_TAG, "connect to the remote device.");
                        esp_ble_gap_stop_scanning();
                        esp_ble_gattc_open(gl_profile_tab[PROFILE_A_APP_ID].gattc_if, scan_result->scan_rst.bda, scan_result->scan_rst.ble_addr_type, true);
                    }
                }
            }
            break;
case ESP_GAP_SEARCH_INQ_RES_EVT:
     esp_log_buffer_hex(GATTC_TAG, scan_result->scan_rst.bda, 6);
ESP_LOGI(GATTC_TAG, "searched Adv Data Len %d, Scan Response Len %d", scan_result->scan_rst.adv_data_len, scan_result->scan_rst.scan_rsp_len);
adv_name = esp_ble_resolve_adv_data(scan_result->scan_rst.ble_adv, ESP_BLE_AD_TYPE_NAME_CMPL, &adv_name_len);
ESP_LOGI(GATTC_TAG, "searched Device Name Len %d", adv_name_len);
esp_log_buffer_char(GATTC_TAG, adv_name, adv_name_len);
     case ESP_GATTC_CONNECT_EVT:
        //p_data->connect.status always be ESP_GATT_OK
        ESP_LOGI(GATTC_TAG, "ESP_GATTC_CONNECT_EVT conn_id %d, if %d, status %d", conn_id, gattc_if, p_data->connect.status);
        conn_id = p_data->connect.conn_id;
        gl_profile_tab[PROFILE_A_APP_ID].conn_id = p_data->connect.conn_id;
        memcpy(gl_profile_tab[PROFILE_A_APP_ID].remote_bda, p_data->connect.remote_bda, sizeof(esp_bd_addr_t));
        ESP_LOGI(GATTC_TAG, "REMOTE BDA:");
        esp_log_buffer_hex(GATTC_TAG, gl_profile_tab[PROFILE_A_APP_ID].remote_bda, sizeof(esp_bd_addr_t));
        esp_err_t mtu_ret = esp_ble_gattc_send_mtu_req (gattc_if, conn_id);
        if (mtu_ret){
            ESP_LOGE(GATTC_TAG, "config MTU error, error code = %x", mtu_ret);
        }
        break;
conn_id = p_data->connect.conn_id;
gl_profile_tab[PROFILE_A_APP_ID].conn_id = p_data->connect.conn_id;
memcpy(gl_profile_tab[PROFILE_A_APP_ID].remote_bda, p_data->connect.remote_bda, 
		sizeof(esp_bd_addr_t));
ESP_LOGI(GATTC_TAG, "REMOTE BDA:");
esp_log_buffer_hex(GATTC_TAG, gl_profile_tab[PROFILE_A_APP_ID].remote_bda, 
		sizeof(esp_bd_addr_t));
esp_err_t mtu_ret = esp_ble_gattc_send_mtu_req (gattc_if, conn_id);
if (mtu_ret){
	ESP_LOGE(GATTC_TAG, "config MTU error, error code = %x", mtu_ret);
}
break;
case ESP_GATTC_OPEN_EVT:
        if (param->open.status != ESP_GATT_OK){
            ESP_LOGE(GATTC_TAG, "open failed, status %d", p_data->open.status);
            break;
        }
ESP_LOGI(GATTC_TAG, "open success");
case ESP_GATTC_CFG_MTU_EVT:
        if (param->cfg_mtu.status != ESP_GATT_OK){
            ESP_LOGE(GATTC_TAG,"config mtu failed, error status = %x", param->cfg_mtu.status);
        }
        ESP_LOGI(GATTC_TAG, "ESP_GATTC_CFG_MTU_EVT, Status %d, MTU %d, conn_id %d", param->cfg_mtu.status, param->cfg_mtu.mtu, param->cfg_mtu.conn_id);
…
static esp_bt_uuid_t remote_filter_service_uuid = {
    .len = ESP_UUID_LEN_16,
    .uuid = {.uuid16 = REMOTE_SERVICE_UUID,},
};
#define REMOTE_SERVICE_UUID        0x00FF
esp_ble_gattc_search_service(gattc_if, param->cfg_mtu.conn_id, &remote_filter_service_uuid);
        break;
 case ESP_GATTC_SEARCH_RES_EVT: {
        esp_gatt_srvc_id_t *srvc_id = &p_data->search_res.srvc_id;
        conn_id = p_data->search_res.conn_id;
        if (srvc_id->id.uuid.len == ESP_UUID_LEN_16 && srvc_id->id.uuid.uuid.uuid16 == 
REMOTE_SERVICE_UUID) {
        get_server = true;
        gl_profile_tab[PROFILE_A_APP_ID].service_start_handle = p_data->search_res.start_handle;
        gl_profile_tab[PROFILE_A_APP_ID].service_end_handle = p_data->search_res.end_handle;
        ESP_LOGI(GATTC_TAG, "UUID16: %x", srvc_id->id.uuid.uuid.uuid16);
        }
        break;
#define REMOTE_NOTIFY_CHAR_UUID    0xFF01
/**
 * @brief Gatt id, include uuid and instance id
 */
typedef struct {
    esp_bt_uuid_t   uuid;                   /*!< UUID */
    uint8_t         inst_id;                /*!< Instance id */
} __attribute__((packed)) esp_gatt_id_t;
static esp_gatt_srvc_id_t remote_service_id = {
    .id = {
        .uuid = {
            .len = ESP_UUID_LEN_16,
            .uuid = {.uuid16 = REMOTE_SERVICE_UUID,},
        },
        .inst_id = 0,
    },
    .is_primary = true,
};
case ESP_GATTC_SEARCH_CMPL_EVT:
    if (p_data->search_cmpl.status != ESP_GATT_OK){
        ESP_LOGE(GATTC_TAG, "search service failed, error status = %x", p_data->search_cmpl.status);
        break;
    }
    conn_id = p_data->search_cmpl.conn_id;
    if (get_server){
        uint16_t count = 0;
        esp_gatt_status_t status = esp_ble_gattc_get_attr_count( gattc_if,
                          p_data->search_cmpl.conn_id,ESP_GATT_DB_CHARACTERISTIC,                                                                                                                 		                    gl_profile_tab[PROFILE_A_APP_ID].service_start_handle,                                                                   		                    gl_profile_tab[PROFILE_A_APP_ID].service_end_handle,        
                                                                INVALID_HANDLE,      	                  
                                                                     &count);
        if (status != ESP_GATT_OK){
            ESP_LOGE(GATTC_TAG, "esp_ble_gattc_get_attr_count error");
        }

        if (count > 0){
            char_elem_result = (esp_gattc_char_elem_t*)malloc
                                          (sizeof(esp_gattc_char_elem_t) * count);
            if (!char_elem_result){
                ESP_LOGE(GATTC_TAG, "gattc no mem");
            }else{
                status = esp_ble_gattc_get_char_by_uuid( gattc_if,
                                                       p_data->search_cmpl.conn_id,                                                                      
                              gl_profile_tab[PROFILE_A_APP_ID].service_start_handle,                                                            
                              gl_profile_tab[PROFILE_A_APP_ID].service_end_handle,
                                                         remote_filter_char_uuid,
                                                         char_elem_result,
                                                         &count);
                if (status != ESP_GATT_OK){
                    ESP_LOGE(GATTC_TAG, "esp_ble_gattc_get_char_by_uuid error");
                }

                /*  Every service have only one char in our 'ESP_GATTS_DEMO' demo,     
                    so we used first 'char_elem_result' */
                if (count > 0 && (char_elem_result[0].properties                       
                                 &ESP_GATT_CHAR_PROP_BIT_NOTIFY)){
                    gl_profile_tab[PROFILE_A_APP_ID].char_handle =  
                    char_elem_result[0].char_handle;
                    esp_ble_gattc_register_for_notify (gattc_if,   
                                   gl_profile_tab[PROFILE_A_APP_ID].remote_bda, 
                                   char_elem_result[0].char_handle);
                }
            }
            /* free char_elem_result */
            free(char_elem_result);
        }else{
            ESP_LOGE(GATTC_TAG, "no char found");
        }        }
        break;
…
/*  Every service have only one char in our 'ESP_GATTS_DEMO' demo, so we used first 'char_elem_result' */
                    if(count > 0 && (char_elem_result[0].properties & ESP_GATT_CHAR_PROP_BIT_NOTIFY)){
                        gl_profile_tab[PROFILE_A_APP_ID].char_handle = char_elem_result[0].char_handle;
                        esp_ble_gattc_register_for_notify (gattc_if, gl_profile_tab[PROFILE_A_APP_ID].remote_bda,
                        char_elem_result[0].char_handle);
                        }
…
    case ESP_GATTC_REG_FOR_NOTIFY_EVT: {
        ESP_LOGI(GATTC_TAG, "ESP_GATTC_REG_FOR_NOTIFY_EVT");
        if (p_data->reg_for_notify.status != ESP_GATT_OK){
            ESP_LOGE(GATTC_TAG, "REG FOR NOTIFY failed: error status = %d", p_data->reg_for_notify.status);
        }else{
            uint16_t count = 0;
            uint16_t notify_en = 1;
            esp_gatt_status_t ret_status = esp_ble_gattc_get_attr_count( gattc_if, gl_profile_tab[PROFILE_A_APP_ID].conn_id,
											            ESP_GATT_DB_DESCRIPTOR,
											            gl_profile_tab[PROFILE_A_APP_ID].service_start_handle,
											            gl_profile_tab[PROFILE_A_APP_ID].service_end_handle,
											            gl_profile_tab[PROFILE_A_APP_ID].char_handle, &count);
            if (ret_status != ESP_GATT_OK){
                ESP_LOGE(GATTC_TAG, "esp_ble_gattc_get_attr_count error");
            }
            if (count > 0){
                descr_elem_result = malloc(sizeof(esp_gattc_descr_elem_t) * count);
                if (!descr_elem_result){
                    ESP_LOGE(GATTC_TAG, "malloc error, gattc no mem");
                }else{
                    ret_status = esp_ble_gattc_get_descr_by_char_handle( 
                    gattc_if, 
                    gl_profile_tab[PROFILE_A_APP_ID].conn_id, 
                    p_data->reg_for_notify.handle, 
                    notify_descr_uuid, 
                    descr_elem_result,&count);
                    
                    if (ret_status != ESP_GATT_OK){
                        ESP_LOGE(GATTC_TAG, "esp_ble_gattc_get_descr_by_char_handle   
                                                                            error");
                    }

                    /* Every char has only one descriptor in our 'ESP_GATTS_DEMO' demo, so we used first 'descr_elem_result' */
                    if (count > 0 && descr_elem_result[0].uuid.len == ESP_UUID_LEN_16 && descr_elem_result[0].uuid.uuid.uuid16 == ESP_GATT_UUID_CHAR_CLIENT_CONFIG){
                        ret_status = esp_ble_gattc_write_char_descr( gattc_if, 
								                        gl_profile_tab[PROFILE_A_APP_ID].conn_id,
								                        descr_elem_result[0].handle,
								                        sizeof(notify_en),
								                        (Uint8 *)&notify_en,
								                        ESP_GATT_WRITE_TYPE_RSP,
								                        ESP_GATT_AUTH_REQ_NONE);
                    }

                    if (ret_status != ESP_GATT_OK){
                        ESP_LOGE(GATTC_TAG, "esp_ble_gattc_write_char_descr error");
                    }

                    /* free descr_elem_result */
                    free(descr_elem_result);
                }
            }
            else{
                ESP_LOGE(GATTC_TAG, "decsr not found");
            }

        }
        break;
    }
static esp_gatt_id_t notify_descr_id = {
    .uuid = {
        .len = ESP_UUID_LEN_16,
        .uuid = {.uuid16 = ESP_GATT_UUID_CHAR_CLIENT_CONFIG,},
    },
    .inst_id = 0,
};
#define ESP_GATT_UUID_CHAR_CLIENT_CONFIG            0x2902          /*  Client Characteristic Configuration */