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 x, 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 *)¬ify_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 */
