BLE_GATT_Client.ino

// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at

//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.



/****************************************************************************
*
* This file is for gatt client. It can scan ble device, connect one device,
*
****************************************************************************/

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

#include "bt.h"
#include "bt_trace.h"
#include "bt_types.h"
#include "btm_api.h"
#include "bta_api.h"
#include "bta_gatt_api.h"
#include "esp_gap_ble_api.h"
#include "esp_gattc_api.h"
#include "esp_gatt_defs.h"
#include "esp_bt_main.h"

#define GATTC_TAG "GATTC_DEMO"

///Declare static functions
static void esp_gap_cb(esp_gap_ble_cb_event_t event, esp_ble_gap_cb_param_t *param);
static void esp_gattc_cb(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_if, esp_ble_gattc_cb_param_t *param);
static void gattc_profile_a_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_if, esp_ble_gattc_cb_param_t *param);
static void gattc_profile_b_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_if, esp_ble_gattc_cb_param_t *param);


static esp_gatt_srvc_id_t alert_service_id = {
    .id = {
        .uuid = {
            .len = ESP_UUID_LEN_16,
            .uuid = {.uuid16 = 0x1811,},
        },
        .inst_id = 0,
    },
    .is_primary = true,
};

static esp_gatt_id_t notify_descr_id = {
    .uuid = {
        .len = ESP_UUID_LEN_16,
        .uuid = {.uuid16 = GATT_UUID_CHAR_CLIENT_CONFIG,},
    },
    .inst_id = 0,
};
#define BT_BD_ADDR_STR         "%02x:%02x:%02x:%02x:%02x:%02x"
#define BT_BD_ADDR_HEX(addr)   addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]

static bool connect = false;
static const char device_name[] = "Alert Notification";

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,
};

#define PROFILE_NUM 2
#define PROFILE_A_APP_ID 0
#define PROFILE_B_APP_ID 1

struct gattc_profile_inst {
    esp_gattc_cb_t gattc_cb;
    uint16_t gattc_if;
    uint16_t app_id;
    uint16_t conn_id;
    esp_bd_addr_t remote_bda;
};

/* 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_a_event_handler,
        .gattc_if = ESP_GATT_IF_NONE,       /* Not get the gatt_if, so initial is ESP_GATT_IF_NONE */
    },
    [PROFILE_B_APP_ID] = {
        .gattc_cb = gattc_profile_b_event_handler,
        .gattc_if = ESP_GATT_IF_NONE,       /* Not get the gatt_if, so initial is ESP_GATT_IF_NONE */
    },
};

static void gattc_profile_a_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_if, esp_ble_gattc_cb_param_t *param)
{
    uint16_t conn_id = 0;
    esp_ble_gattc_cb_param_t *p_data = (esp_ble_gattc_cb_param_t *)param;

    switch (event) {
    case ESP_GATTC_REG_EVT:
        Serial.printf("REG_EVT\n");
        esp_ble_gap_set_scan_params(&ble_scan_params);
        break;
    case ESP_GATTC_OPEN_EVT:
        conn_id = p_data->open.conn_id;

        memcpy(gl_profile_tab[PROFILE_A_APP_ID].remote_bda, p_data->open.remote_bda, sizeof(esp_bd_addr_t));
        Serial.printf("ESP_GATTC_OPEN_EVT conn_id %d, if %d, status %d, mtu %d\n", conn_id, gattc_if, p_data->open.status, p_data->open.mtu);

        Serial.printf("REMOTE BDA  %02x:%02x:%02x:%02x:%02x:%02x\n",
                            gl_profile_tab[PROFILE_A_APP_ID].remote_bda[0], gl_profile_tab[PROFILE_A_APP_ID].remote_bda[1], 
                            gl_profile_tab[PROFILE_A_APP_ID].remote_bda[2], gl_profile_tab[PROFILE_A_APP_ID].remote_bda[3],
                            gl_profile_tab[PROFILE_A_APP_ID].remote_bda[4], gl_profile_tab[PROFILE_A_APP_ID].remote_bda[5]
                         );

        esp_ble_gattc_search_service(gattc_if, conn_id, NULL);
        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;
        Serial.printf("SEARCH RES: conn_id = %x\n", conn_id);
        if (srvc_id->id.uuid.len == ESP_UUID_LEN_16) {
            Serial.printf("UUID16: %x\n", srvc_id->id.uuid.uuid.uuid16);
        } else if (srvc_id->id.uuid.len == ESP_UUID_LEN_32) {
            Serial.printf("UUID32: %x\n", srvc_id->id.uuid.uuid.uuid32);
        } else if (srvc_id->id.uuid.len == ESP_UUID_LEN_128) {
            Serial.printf("UUID128: %x,%x,%x,%x,%x,%x,%x,%x,%x,%x,%x,%x,%x,%x,%x,%x\n", srvc_id->id.uuid.uuid.uuid128[0],
                     srvc_id->id.uuid.uuid.uuid128[1], srvc_id->id.uuid.uuid.uuid128[2], srvc_id->id.uuid.uuid.uuid128[3],
                     srvc_id->id.uuid.uuid.uuid128[4], srvc_id->id.uuid.uuid.uuid128[5], srvc_id->id.uuid.uuid.uuid128[6],
                     srvc_id->id.uuid.uuid.uuid128[7], srvc_id->id.uuid.uuid.uuid128[8], srvc_id->id.uuid.uuid.uuid128[9],
                     srvc_id->id.uuid.uuid.uuid128[10], srvc_id->id.uuid.uuid.uuid128[11], srvc_id->id.uuid.uuid.uuid128[12],
                     srvc_id->id.uuid.uuid.uuid128[13], srvc_id->id.uuid.uuid.uuid128[14], srvc_id->id.uuid.uuid.uuid128[15]);
        } else {
            Serial.printf("ERROR: UNKNOWN LEN %d\n", srvc_id->id.uuid.len);
        }
        break;
    }
    case ESP_GATTC_SEARCH_CMPL_EVT:
        conn_id = p_data->search_cmpl.conn_id;
        Serial.printf("SEARCH_CMPL: conn_id = %x, status %d\n", conn_id, p_data->search_cmpl.status);
        esp_ble_gattc_get_characteristic(gattc_if, conn_id, &alert_service_id, NULL);
        break;
    case ESP_GATTC_GET_CHAR_EVT:
        if (p_data->get_char.status != ESP_GATT_OK) {
            break;
        }
        Serial.printf("GET CHAR: conn_id = %x, status %d\n", p_data->get_char.conn_id, p_data->get_char.status);
        Serial.printf("GET CHAR: srvc_id = %04x, char_id = %04x\n", p_data->get_char.srvc_id.id.uuid.uuid.uuid16, p_data->get_char.char_id.uuid.uuid.uuid16);

        if (p_data->get_char.char_id.uuid.uuid.uuid16 == 0x2a46) {
            Serial.printf("register notify\n");
            esp_ble_gattc_register_for_notify(gattc_if, gl_profile_tab[PROFILE_A_APP_ID].remote_bda, &alert_service_id, &p_data->get_char.char_id);
        }

        esp_ble_gattc_get_characteristic(gattc_if, conn_id, &alert_service_id, &p_data->get_char.char_id);
        break;
    case ESP_GATTC_REG_FOR_NOTIFY_EVT: {
        uint16_t notify_en = 1;
        Serial.printf("REG FOR NOTIFY: status %d\n", p_data->reg_for_notify.status);
        Serial.printf("REG FOR_NOTIFY: srvc_id = %04x, char_id = %04x\n", p_data->reg_for_notify.srvc_id.id.uuid.uuid.uuid16, p_data->reg_for_notify.char_id.uuid.uuid.uuid16);

        esp_ble_gattc_write_char_descr(
                gattc_if,
                conn_id,
                &alert_service_id,
                &p_data->reg_for_notify.char_id,
                &notify_descr_id,
                sizeof(notify_en),
                (uint8_t *)&notify_en,
                ESP_GATT_WRITE_TYPE_RSP,
                ESP_GATT_AUTH_REQ_NONE);
        break;
    }
    case ESP_GATTC_NOTIFY_EVT:
        Serial.printf("NOTIFY: len %d, value %08x\n", p_data->notify.value_len, *(uint32_t *)p_data->notify.value);
        break;
    case ESP_GATTC_WRITE_DESCR_EVT:
        Serial.printf("WRITE: status %d\n", p_data->write.status);
        break;
    default:
        break;
    }
}

static void gattc_profile_b_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_if, esp_ble_gattc_cb_param_t *param)
{
    uint16_t conn_id = 0;
    esp_ble_gattc_cb_param_t *p_data = (esp_ble_gattc_cb_param_t *)param;

    switch (event) {
    case ESP_GATTC_REG_EVT:
        Serial.printf("REG_EVT\n");
        break;
    case ESP_GATTC_OPEN_EVT:
        conn_id = p_data->open.conn_id;

        memcpy(gl_profile_tab[PROFILE_B_APP_ID].remote_bda, p_data->open.remote_bda, sizeof(esp_bd_addr_t));
        Serial.printf("ESP_GATTC_OPEN_EVT conn_id %d, if %d, status %d, mtu %d\n", conn_id, gattc_if, p_data->open.status, p_data->open.mtu);

        Serial.printf("REMOTE BDA  %02x:%02x:%02x:%02x:%02x:%02x\n",
                            gl_profile_tab[PROFILE_B_APP_ID].remote_bda[0], gl_profile_tab[PROFILE_B_APP_ID].remote_bda[1], 
                            gl_profile_tab[PROFILE_B_APP_ID].remote_bda[2], gl_profile_tab[PROFILE_B_APP_ID].remote_bda[3],
                            gl_profile_tab[PROFILE_B_APP_ID].remote_bda[4], gl_profile_tab[PROFILE_B_APP_ID].remote_bda[5]
                         );

        esp_ble_gattc_search_service(gattc_if, conn_id, NULL);
        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;
        Serial.printf("SEARCH RES: conn_id = %x\n", conn_id);
        if (srvc_id->id.uuid.len == ESP_UUID_LEN_16) {
            Serial.printf("UUID16: %x\n", srvc_id->id.uuid.uuid.uuid16);
        } else if (srvc_id->id.uuid.len == ESP_UUID_LEN_32) {
            Serial.printf("UUID32: %x\n", srvc_id->id.uuid.uuid.uuid32);
        } else if (srvc_id->id.uuid.len == ESP_UUID_LEN_128) {
            Serial.printf("UUID128: %x,%x,%x,%x,%x,%x,%x,%x,%x,%x,%x,%x,%x,%x,%x,%x\n", srvc_id->id.uuid.uuid.uuid128[0],
                     srvc_id->id.uuid.uuid.uuid128[1], srvc_id->id.uuid.uuid.uuid128[2], srvc_id->id.uuid.uuid.uuid128[3],
                     srvc_id->id.uuid.uuid.uuid128[4], srvc_id->id.uuid.uuid.uuid128[5], srvc_id->id.uuid.uuid.uuid128[6],
                     srvc_id->id.uuid.uuid.uuid128[7], srvc_id->id.uuid.uuid.uuid128[8], srvc_id->id.uuid.uuid.uuid128[9],
                     srvc_id->id.uuid.uuid.uuid128[10], srvc_id->id.uuid.uuid.uuid128[11], srvc_id->id.uuid.uuid.uuid128[12],
                     srvc_id->id.uuid.uuid.uuid128[13], srvc_id->id.uuid.uuid.uuid128[14], srvc_id->id.uuid.uuid.uuid128[15]);
        } else {
            Serial.printf("ERROR: UNKNOWN LEN %d\n", srvc_id->id.uuid.len);
        }
        break;
    }
    case ESP_GATTC_SEARCH_CMPL_EVT:
        conn_id = p_data->search_cmpl.conn_id;
        Serial.printf("SEARCH_CMPL: conn_id = %x, status %d\n", conn_id, p_data->search_cmpl.status);
        esp_ble_gattc_get_characteristic(gattc_if, conn_id, &alert_service_id, NULL);
        break;
    case ESP_GATTC_GET_CHAR_EVT:
        if (p_data->get_char.status != ESP_GATT_OK) {
            break;
        }
        Serial.printf("GET CHAR: conn_id = %x, status %d\n", p_data->get_char.conn_id, p_data->get_char.status);
        Serial.printf("GET CHAR: srvc_id = %04x, char_id = %04x\n", p_data->get_char.srvc_id.id.uuid.uuid.uuid16, p_data->get_char.char_id.uuid.uuid.uuid16);

        if (p_data->get_char.char_id.uuid.uuid.uuid16 == 0x2a46) {
            Serial.printf("register notify\n");
            esp_ble_gattc_register_for_notify(gattc_if, gl_profile_tab[PROFILE_B_APP_ID].remote_bda, &alert_service_id, &p_data->get_char.char_id);
        }

        esp_ble_gattc_get_characteristic(gattc_if, conn_id, &alert_service_id, &p_data->get_char.char_id);
        break;
    case ESP_GATTC_REG_FOR_NOTIFY_EVT: {
        uint16_t notify_en = 1;
        Serial.printf("REG FOR NOTIFY: status %d\n", p_data->reg_for_notify.status);
        Serial.printf("REG FOR_NOTIFY: srvc_id = %04x, char_id = %04x\n", p_data->reg_for_notify.srvc_id.id.uuid.uuid.uuid16, p_data->reg_for_notify.char_id.uuid.uuid.uuid16);

        esp_ble_gattc_write_char_descr(
                gattc_if,
                conn_id,
                &alert_service_id,
                &p_data->reg_for_notify.char_id,
                &notify_descr_id,
                sizeof(notify_en),
                (uint8_t *)&notify_en,
                ESP_GATT_WRITE_TYPE_RSP,
                ESP_GATT_AUTH_REQ_NONE);
        break;
    }
    case ESP_GATTC_NOTIFY_EVT:
        Serial.printf("NOTIFY: len %d, value %08x\n", p_data->notify.value_len, *(uint32_t *)p_data->notify.value);
        break;
    case ESP_GATTC_WRITE_DESCR_EVT:
        Serial.printf("WRITE: status %d\n", p_data->write.status);
        break;
    default:
        break;
    }
}

static void esp_gap_cb(esp_gap_ble_cb_event_t event, esp_ble_gap_cb_param_t *param)
{
    uint8_t *adv_name = NULL;
    uint8_t adv_name_len = 0;
    switch (event) {
    case ESP_GAP_BLE_SCAN_PARAM_SET_COMPLETE_EVT: {
        //the unit of the duration is second
        uint32_t duration = 10;
        esp_ble_gap_start_scanning(duration);
        break;
    }
    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:
            for (int i = 0; i < 6; i++) {
                Serial.printf("%x:", scan_result->scan_rst.bda[i]);
            }
            Serial.printf("\n");
            adv_name = esp_ble_resolve_adv_data(scan_result->scan_rst.ble_adv,
                                                ESP_BLE_AD_TYPE_NAME_CMPL, &adv_name_len);
            Serial.printf("Searched Device Name Len %d\n", adv_name_len);
            for (int j = 0; j < adv_name_len; j++) {
                Serial.printf("%c", adv_name[j]);
            }

            if (adv_name != NULL) {
                if (strcmp((char *)adv_name, device_name) == 0) {
                    Serial.printf("Searched device %s\n", device_name);
                    if (connect == false) {
                        connect = true;
                        Serial.printf("Connect to the remote device.\n");
                        esp_ble_gap_stop_scanning();
                        esp_ble_gattc_open(gl_profile_tab[PROFILE_A_APP_ID].gattc_if, scan_result->scan_rst.bda, true);
                        esp_ble_gattc_open(gl_profile_tab[PROFILE_B_APP_ID].gattc_if, scan_result->scan_rst.bda, true);
                    }
                }
            }
            break;
        case ESP_GAP_SEARCH_INQ_CMPL_EVT:
            break;
        default:
            break;
        }
        break;
    }
    default:
        break;
    }
}

static void esp_gattc_cb(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_if, esp_ble_gattc_cb_param_t *param)
{
    Serial.printf("EVT %d, gattc if %d\n", 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 {
            Serial.printf("Reg app failed, app_id %04x, status %d\n",
                    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);
}

void ble_client_appRegister(void)
{
    esp_err_t status;

    Serial.printf("register callback\n");

    //register the scan callback function to the gap moudule
    if ((status = esp_ble_gap_register_callback(esp_gap_cb)) != ESP_OK) {
        Serial.printf("ERROR: gap register error, error code = %x\n", status);
        return;
    }

    //register the callback function to the gattc module
    if ((status = esp_ble_gattc_register_callback(esp_gattc_cb)) != ESP_OK) {
        Serial.printf("ERROR: gattc register error, error code = %x\n", status);
        return;
    }
    esp_ble_gattc_app_register(PROFILE_A_APP_ID);
    esp_ble_gattc_app_register(PROFILE_B_APP_ID);
}

void gattc_client_test(void)
{
    esp_bluedroid_init();
    esp_bluedroid_enable();
    ble_client_appRegister();
}

void setup() {
  Serial.begin(115200);
  if(btStart()){
    gattc_client_test();
  }
}

void loop() {
  // put your main code here, to run repeatedly:

}

hi, this code perfectly works. But the ESP32 BLE scans for 10seconds and stops. Is there any possiblity that it can scan continously or to restart the BLE scan so that it can scan for every 10seconds??

Hi. @JJANANIPRIYA
yes, it is possible.
you want to add scan function in "esp_gap_cb" this function case is there.
like this,
case ESP_GAP_SEARCH_INQ_CMPL_EVT: esp_ble_gap_start_scanning(10); break;

it will work

hi, Thank you for code, but i want to help about find rssi value of device. can you help me ?

Thank you

Peeps, I wish I was more knowledgeable, but sadly I'm still struggling. Can anyone show the extra code required to show the RSSI for the beacons that are detected? Much appreciated.

tengo un problema con

In function 'void gattc_profile_a_event_handler(esp_gattc_cb_event_t, esp_gatt_if_t, esp_ble_gattc_cb_param_t*)':

you:109: error: cannot convert 'esp_gatt_id_t*' to 'esp_gatt_srvc_id_t*' in initialization

     esp_gatt_srvc_id_t *srvc_id = &p_data->search_res.srvc_id;

exit status 1
cannot convert 'esp_gatt_id_t*' to 'esp_gatt_srvc_id_t*' in initialization
¿podria alguien ayudarme?

Got the same problem as @WenMaGape. Is there a solution to this?

Got the same problem as @WenMaGape&@SrishtiPalani. Is there a solution to this?

Me too. Appreciate your help please.

Hi I have a tiny beacon that broadcasts temperature and humidity every seconds using eddystone protocol. Could you please help how I can get these values?

hello every one i downloaded this arduino sketch to scan the bluetooth macs but when i compiled that there was some errors.
please help

Hii to everyone I am very new to this ..Cab anyone tell me ..How to get the libraries used in this program?