GATT SERVER API¶
Overview¶
Application Example¶
Check bluetooth/bluedroid/ble folder in ESP-IDF examples, which contains the following demos and their tutorials:
- This is a GATT sever demo and its tutorial. This demo creates a GATT service with an attribute table, which releases the user from adding attributes one by one. This is the recommended method of adding attributes. 
- This is a GATT server demo and its tutorial. This demo creates a GATT service by adding attributes one by one as defined by Bluedroid. The recommended method of adding attributes is presented in example above. 
- This is a BLE SPP-Like demo. This demo, which acts as a GATT server, can receive data from UART and then send the data to the peer device automatically. 
API Reference¶
Functions¶
- 
esp_err_t esp_ble_gatts_register_callback(esp_gatts_cb_t callback)¶
- This function is called to register application callbacks with BTA GATTS module. - Return
- ESP_OK : success
- other : failed
 
 
- 
esp_err_t esp_ble_gatts_app_register(uint16_t app_id)¶
- This function is called to register application identifier. - Return
- ESP_OK : success
- other : failed
 
 
- 
esp_err_t esp_ble_gatts_app_unregister(esp_gatt_if_t gatts_if)¶
- unregister with GATT Server. - Return
- ESP_OK : success
- other : failed
 
- Parameters
- gatts_if: GATT server access interface
 
 
- 
esp_err_t esp_ble_gatts_create_service(esp_gatt_if_t gatts_if, esp_gatt_srvc_id_t *service_id, uint16_t num_handle)¶
- Create a service. When service creation is done, a callback event ESP_GATTS_CREATE_EVT is called to report status and service ID to the profile. The service ID obtained in the callback function needs to be used when adding included service and characteristics/descriptors into the service. - Return
- ESP_OK : success
- other : failed
 
- Parameters
- gatts_if: GATT server access interface
- service_id: service ID.
- num_handle: number of handle requested for this service.
 
 
- 
esp_err_t esp_ble_gatts_create_attr_tab(const esp_gatts_attr_db_t *gatts_attr_db, esp_gatt_if_t gatts_if, uint8_t max_nb_attr, uint8_t srvc_inst_id)¶
- Create a service attribute tab. - Return
- ESP_OK : success
- other : failed
 
- Parameters
- gatts_attr_db: the pointer to the service attr tab
- gatts_if: GATT server access interface
- max_nb_attr: the number of attribute to be added to the service database.
- srvc_inst_id: the instance id of the service
 
 
- 
esp_err_t esp_ble_gatts_add_included_service(uint16_t service_handle, uint16_t included_service_handle)¶
- This function is called to add an included service. This function have to be called between ‘esp_ble_gatts_create_service’ and ‘esp_ble_gatts_add_char’. After included service is included, a callback event ESP_GATTS_ADD_INCL_SRVC_EVT is reported the included service ID. - Return
- ESP_OK : success
- other : failed
 
- Parameters
- service_handle: service handle to which this included service is to be added.
- included_service_handle: the service ID to be included.
 
 
- 
esp_err_t esp_ble_gatts_add_char(uint16_t service_handle, esp_bt_uuid_t *char_uuid, esp_gatt_perm_t perm, esp_gatt_char_prop_t property, esp_attr_value_t *char_val, esp_attr_control_t *control)¶
- This function is called to add a characteristic into a service. - Return
- ESP_OK : success
- other : failed
 
- Parameters
- service_handle: service handle to which this included service is to be added.
- char_uuid: : Characteristic UUID.
- perm: : Characteristic value declaration attribute permission.
- property: : Characteristic Properties
- char_val: : Characteristic value
- control: : attribute response control byte
 
 
- 
esp_err_t esp_ble_gatts_add_char_descr(uint16_t service_handle, esp_bt_uuid_t *descr_uuid, esp_gatt_perm_t perm, esp_attr_value_t *char_descr_val, esp_attr_control_t *control)¶
- This function is called to add characteristic descriptor. When it’s done, a callback event ESP_GATTS_ADD_DESCR_EVT is called to report the status and an ID number for this descriptor. - Return
- ESP_OK : success
- other : failed
 
- Parameters
- service_handle: service handle to which this characteristic descriptor is to be added.
- perm: descriptor access permission.
- descr_uuid: descriptor UUID.
- char_descr_val: : Characteristic descriptor value
- control: : attribute response control byte
 
 
- 
esp_err_t esp_ble_gatts_delete_service(uint16_t service_handle)¶
- This function is called to delete a service. When this is done, a callback event ESP_GATTS_DELETE_EVT is report with the status. - Return
- ESP_OK : success
- other : failed
 
- Parameters
- service_handle: service_handle to be deleted.
 
 
- 
esp_err_t esp_ble_gatts_start_service(uint16_t service_handle)¶
- This function is called to start a service. - Return
- ESP_OK : success
- other : failed
 
- Parameters
- service_handle: the service handle to be started.
 
 
- 
esp_err_t esp_ble_gatts_stop_service(uint16_t service_handle)¶
- This function is called to stop a service. - Return
- ESP_OK : success
- other : failed
 
- Parameters
- service_handle: - service to be topped.
 
 
- 
esp_err_t esp_ble_gatts_send_indicate(esp_gatt_if_t gatts_if, uint16_t conn_id, uint16_t attr_handle, uint16_t value_len, uint8_t *value, bool need_confirm)¶
- Send indicate or notify to GATT client. Set param need_confirm as false will send notification, otherwise indication. - Return
- ESP_OK : success
- other : failed
 
- Parameters
- gatts_if: GATT server access interface
- conn_id: - connection id to indicate.
- attr_handle: - attribute handle to indicate.
- value_len: - indicate value length.
- value: value to indicate.
- need_confirm: - Whether a confirmation is required. false sends a GATT notification, true sends a GATT indication.
 
 
- 
esp_err_t esp_ble_gatts_send_response(esp_gatt_if_t gatts_if, uint16_t conn_id, uint32_t trans_id, esp_gatt_status_t status, esp_gatt_rsp_t *rsp)¶
- This function is called to send a response to a request. - Return
- ESP_OK : success
- other : failed
 
- Parameters
- gatts_if: GATT server access interface
- conn_id: - connection identifier.
- trans_id: - transfer id
- status: - response status
- rsp: - response data.
 
 
- 
esp_err_t esp_ble_gatts_set_attr_value(uint16_t attr_handle, uint16_t length, const uint8_t *value)¶
- This function is called to set the attribute value by the application. - Return
- ESP_OK : success
- other : failed
 
- Parameters
- attr_handle: the attribute handle which to be set
- length: the value length
- value: the pointer to the attribute value
 
 
- 
esp_gatt_status_t esp_ble_gatts_get_attr_value(uint16_t attr_handle, uint16_t *length, const uint8_t **value)¶
- Retrieve attribute value. - Return
- ESP_GATT_OK : success
- other : failed
 
- Parameters
- attr_handle: Attribute handle.
- length: pointer to the attribute value length
- value: Pointer to attribute value payload, the value cannot be modified by user
 
 
- 
esp_err_t esp_ble_gatts_open(esp_gatt_if_t gatts_if, esp_bd_addr_t remote_bda, bool is_direct)¶
- Open a direct open connection or add a background auto connection. - Return
- ESP_OK : success
- other : failed
 
- Parameters
- gatts_if: GATT server access interface
- remote_bda: remote device bluetooth device address.
- is_direct: direct connection or background auto connection
 
 
- 
esp_err_t esp_ble_gatts_close(esp_gatt_if_t gatts_if, uint16_t conn_id)¶
- Close a connection a remote device. - Return
- ESP_OK : success
- other : failed
 
- Parameters
- gatts_if: GATT server access interface
- conn_id: connection ID to be closed.
 
 
- 
esp_err_t esp_ble_gatts_send_service_change_indication(esp_gatt_if_t gatts_if, esp_bd_addr_t remote_bda)¶
- Send service change indication. - Return
- ESP_OK : success
- other : failed
 
- Parameters
- gatts_if: GATT server access interface
- remote_bda: remote device bluetooth device address. If remote_bda is NULL then it will send service change indication to all the connected devices and if not then to a specific device
 
 
Unions¶
- 
union esp_ble_gatts_cb_param_t¶
- #include <esp_gatts_api.h>Gatt server callback parameters union. Public Members - 
struct esp_ble_gatts_cb_param_t::gatts_reg_evt_param reg¶
- Gatt server callback param of ESP_GATTS_REG_EVT 
 - 
struct esp_ble_gatts_cb_param_t::gatts_read_evt_param read¶
- Gatt server callback param of ESP_GATTS_READ_EVT 
 - 
struct esp_ble_gatts_cb_param_t::gatts_write_evt_param write¶
- Gatt server callback param of ESP_GATTS_WRITE_EVT 
 - 
struct esp_ble_gatts_cb_param_t::gatts_exec_write_evt_param exec_write¶
- Gatt server callback param of ESP_GATTS_EXEC_WRITE_EVT 
 - 
struct esp_ble_gatts_cb_param_t::gatts_mtu_evt_param mtu¶
- Gatt server callback param of ESP_GATTS_MTU_EVT 
 - 
struct esp_ble_gatts_cb_param_t::gatts_conf_evt_param conf¶
- Gatt server callback param of ESP_GATTS_CONF_EVT (confirm) 
 - 
struct esp_ble_gatts_cb_param_t::gatts_create_evt_param create¶
- Gatt server callback param of ESP_GATTS_CREATE_EVT 
 - 
struct esp_ble_gatts_cb_param_t::gatts_add_incl_srvc_evt_param add_incl_srvc¶
- Gatt server callback param of ESP_GATTS_ADD_INCL_SRVC_EVT 
 - 
struct esp_ble_gatts_cb_param_t::gatts_add_char_evt_param add_char¶
- Gatt server callback param of ESP_GATTS_ADD_CHAR_EVT 
 - 
struct esp_ble_gatts_cb_param_t::gatts_add_char_descr_evt_param add_char_descr¶
- Gatt server callback param of ESP_GATTS_ADD_CHAR_DESCR_EVT 
 - 
struct esp_ble_gatts_cb_param_t::gatts_delete_evt_param del¶
- Gatt server callback param of ESP_GATTS_DELETE_EVT 
 - 
struct esp_ble_gatts_cb_param_t::gatts_start_evt_param start¶
- Gatt server callback param of ESP_GATTS_START_EVT 
 - 
struct esp_ble_gatts_cb_param_t::gatts_stop_evt_param stop¶
- Gatt server callback param of ESP_GATTS_STOP_EVT 
 - 
struct esp_ble_gatts_cb_param_t::gatts_connect_evt_param connect¶
- Gatt server callback param of ESP_GATTS_CONNECT_EVT 
 - 
struct esp_ble_gatts_cb_param_t::gatts_disconnect_evt_param disconnect¶
- Gatt server callback param of ESP_GATTS_DISCONNECT_EVT 
 - 
struct esp_ble_gatts_cb_param_t::gatts_open_evt_param open¶
- Gatt server callback param of ESP_GATTS_OPEN_EVT 
 - 
struct esp_ble_gatts_cb_param_t::gatts_cancel_open_evt_param cancel_open¶
- Gatt server callback param of ESP_GATTS_CANCEL_OPEN_EVT 
 - 
struct esp_ble_gatts_cb_param_t::gatts_close_evt_param close¶
- Gatt server callback param of ESP_GATTS_CLOSE_EVT 
 - 
struct esp_ble_gatts_cb_param_t::gatts_congest_evt_param congest¶
- Gatt server callback param of ESP_GATTS_CONGEST_EVT 
 - 
struct esp_ble_gatts_cb_param_t::gatts_rsp_evt_param rsp¶
- Gatt server callback param of ESP_GATTS_RESPONSE_EVT 
 - 
struct esp_ble_gatts_cb_param_t::gatts_add_attr_tab_evt_param add_attr_tab¶
- Gatt server callback param of ESP_GATTS_CREAT_ATTR_TAB_EVT 
 - 
struct esp_ble_gatts_cb_param_t::gatts_set_attr_val_evt_param set_attr_val¶
- Gatt server callback param of ESP_GATTS_SET_ATTR_VAL_EVT 
 - 
struct esp_ble_gatts_cb_param_t::gatts_send_service_change_evt_param service_change¶
- Gatt server callback param of ESP_GATTS_SEND_SERVICE_CHANGE_EVT 
 - 
struct gatts_add_attr_tab_evt_param¶
- #include <esp_gatts_api.h>ESP_GATTS_CREAT_ATTR_TAB_EVT. Public Members - 
esp_gatt_status_t status¶
- Operation status 
 - 
esp_bt_uuid_t svc_uuid¶
- Service uuid type 
 - 
uint8_t svc_inst_id¶
- Service id 
 - 
uint16_t num_handle¶
- The number of the attribute handle to be added to the gatts database 
 - 
uint16_t *handles¶
- The number to the handles 
 
- 
esp_gatt_status_t 
 - 
struct gatts_add_char_descr_evt_param¶
- #include <esp_gatts_api.h>ESP_GATTS_ADD_CHAR_DESCR_EVT. Public Members - 
esp_gatt_status_t status¶
- Operation status 
 - 
uint16_t attr_handle¶
- Descriptor attribute handle 
 - 
uint16_t service_handle¶
- Service attribute handle 
 - 
esp_bt_uuid_t descr_uuid¶
- Characteristic descriptor uuid 
 
- 
esp_gatt_status_t 
 - 
struct gatts_add_char_evt_param¶
- #include <esp_gatts_api.h>ESP_GATTS_ADD_CHAR_EVT. Public Members - 
esp_gatt_status_t status¶
- Operation status 
 - 
uint16_t attr_handle¶
- Characteristic attribute handle 
 - 
uint16_t service_handle¶
- Service attribute handle 
 - 
esp_bt_uuid_t char_uuid¶
- Characteristic uuid 
 
- 
esp_gatt_status_t 
 - 
struct gatts_add_incl_srvc_evt_param¶
- #include <esp_gatts_api.h>ESP_GATTS_ADD_INCL_SRVC_EVT. Public Members - 
esp_gatt_status_t status¶
- Operation status 
 - 
uint16_t attr_handle¶
- Included service attribute handle 
 - 
uint16_t service_handle¶
- Service attribute handle 
 
- 
esp_gatt_status_t 
 - 
struct gatts_cancel_open_evt_param¶
- #include <esp_gatts_api.h>ESP_GATTS_CANCEL_OPEN_EVT. Public Members - 
esp_gatt_status_t status¶
- Operation status 
 
- 
esp_gatt_status_t 
 - 
struct gatts_close_evt_param¶
- #include <esp_gatts_api.h>ESP_GATTS_CLOSE_EVT. 
 - 
struct gatts_conf_evt_param¶
- #include <esp_gatts_api.h>ESP_GATTS_CONF_EVT. Public Members - 
esp_gatt_status_t status¶
- Operation status 
 - 
uint16_t conn_id¶
- Connection id 
 - 
uint16_t handle¶
- attribute handle 
 - 
uint16_t len¶
- The indication or notification value length, len is valid when send notification or indication failed 
 - 
uint8_t *value¶
- The indication or notification value , value is valid when send notification or indication failed 
 
- 
esp_gatt_status_t 
 - 
struct gatts_congest_evt_param¶
- #include <esp_gatts_api.h>ESP_GATTS_LISTEN_EVT. ESP_GATTS_CONGEST_EVT 
 - 
struct gatts_connect_evt_param¶
- #include <esp_gatts_api.h>ESP_GATTS_CONNECT_EVT. Public Members - 
uint16_t conn_id¶
- Connection id 
 - 
esp_bd_addr_t remote_bda¶
- Remote bluetooth device address 
 - 
esp_gatt_conn_params_t conn_params¶
- current Connection parameters 
 
- 
uint16_t 
 - 
struct gatts_create_evt_param¶
- #include <esp_gatts_api.h>ESP_GATTS_UNREG_EVT. ESP_GATTS_CREATE_EVT Public Members - 
esp_gatt_status_t status¶
- Operation status 
 - 
uint16_t service_handle¶
- Service attribute handle 
 - 
esp_gatt_srvc_id_t service_id¶
- Service id, include service uuid and other information 
 
- 
esp_gatt_status_t 
 - 
struct gatts_delete_evt_param¶
- #include <esp_gatts_api.h>ESP_GATTS_DELETE_EVT. Public Members - 
esp_gatt_status_t status¶
- Operation status 
 - 
uint16_t service_handle¶
- Service attribute handle 
 
- 
esp_gatt_status_t 
 - 
struct gatts_disconnect_evt_param¶
- #include <esp_gatts_api.h>ESP_GATTS_DISCONNECT_EVT. Public Members - 
uint16_t conn_id¶
- Connection id 
 - 
esp_bd_addr_t remote_bda¶
- Remote bluetooth device address 
 - 
esp_gatt_conn_reason_t reason¶
- Indicate the reason of disconnection 
 
- 
uint16_t 
 - 
struct gatts_exec_write_evt_param¶
- #include <esp_gatts_api.h>ESP_GATTS_EXEC_WRITE_EVT. Public Members - 
uint16_t conn_id¶
- Connection id 
 - 
uint32_t trans_id¶
- Transfer id 
 - 
esp_bd_addr_t bda¶
- The bluetooth device address which been written 
 - 
uint8_t exec_write_flag¶
- Execute write flag 
 
- 
uint16_t 
 - 
struct gatts_mtu_evt_param¶
- #include <esp_gatts_api.h>ESP_GATTS_MTU_EVT. 
 - 
struct gatts_open_evt_param¶
- #include <esp_gatts_api.h>ESP_GATTS_OPEN_EVT. Public Members - 
esp_gatt_status_t status¶
- Operation status 
 
- 
esp_gatt_status_t 
 - 
struct gatts_read_evt_param¶
- #include <esp_gatts_api.h>ESP_GATTS_READ_EVT. Public Members - 
uint16_t conn_id¶
- Connection id 
 - 
uint32_t trans_id¶
- Transfer id 
 - 
esp_bd_addr_t bda¶
- The bluetooth device address which been read 
 - 
uint16_t handle¶
- The attribute handle 
 - 
uint16_t offset¶
- Offset of the value, if the value is too long 
 - 
bool is_long¶
- The value is too long or not 
 - 
bool need_rsp¶
- The read operation need to do response 
 
- 
uint16_t 
 - 
struct gatts_reg_evt_param¶
- #include <esp_gatts_api.h>ESP_GATTS_REG_EVT. Public Members - 
esp_gatt_status_t status¶
- Operation status 
 - 
uint16_t app_id¶
- Application id which input in register API 
 
- 
esp_gatt_status_t 
 - 
struct gatts_rsp_evt_param¶
- #include <esp_gatts_api.h>ESP_GATTS_RESPONSE_EVT. Public Members - 
esp_gatt_status_t status¶
- Operation status 
 - 
uint16_t handle¶
- Attribute handle which send response 
 
- 
esp_gatt_status_t 
 - 
struct gatts_send_service_change_evt_param¶
- #include <esp_gatts_api.h>ESP_GATTS_SEND_SERVICE_CHANGE_EVT. Public Members - 
esp_gatt_status_t status¶
- Operation status 
 
- 
esp_gatt_status_t 
 - 
struct gatts_set_attr_val_evt_param¶
- #include <esp_gatts_api.h>ESP_GATTS_SET_ATTR_VAL_EVT. Public Members - 
uint16_t srvc_handle¶
- The service handle 
 - 
uint16_t attr_handle¶
- The attribute handle 
 - 
esp_gatt_status_t status¶
- Operation status 
 
- 
uint16_t 
 - 
struct gatts_start_evt_param¶
- #include <esp_gatts_api.h>ESP_GATTS_START_EVT. Public Members - 
esp_gatt_status_t status¶
- Operation status 
 - 
uint16_t service_handle¶
- Service attribute handle 
 
- 
esp_gatt_status_t 
 - 
struct gatts_stop_evt_param¶
- #include <esp_gatts_api.h>ESP_GATTS_STOP_EVT. Public Members - 
esp_gatt_status_t status¶
- Operation status 
 - 
uint16_t service_handle¶
- Service attribute handle 
 
- 
esp_gatt_status_t 
 - 
struct gatts_write_evt_param¶
- #include <esp_gatts_api.h>ESP_GATTS_WRITE_EVT. Public Members - 
uint16_t conn_id¶
- Connection id 
 - 
uint32_t trans_id¶
- Transfer id 
 - 
esp_bd_addr_t bda¶
- The bluetooth device address which been written 
 - 
uint16_t handle¶
- The attribute handle 
 - 
uint16_t offset¶
- Offset of the value, if the value is too long 
 - 
bool need_rsp¶
- The write operation need to do response 
 - 
bool is_prep¶
- This write operation is prepare write 
 - 
uint16_t len¶
- The write attribute value length 
 - 
uint8_t *value¶
- The write attribute value 
 
- 
uint16_t 
 
- 
struct esp_ble_gatts_cb_param_t::gatts_reg_evt_param 
Macros¶
- 
ESP_GATT_PREP_WRITE_CANCEL¶
- Prepare write flag to indicate cancel prepare write 
- 
ESP_GATT_PREP_WRITE_EXEC¶
- Prepare write flag to indicate execute prepare write 
Type Definitions¶
- 
typedef void (*esp_gatts_cb_t)(esp_gatts_cb_event_t event, esp_gatt_if_t gatts_if, esp_ble_gatts_cb_param_t *param)¶
- GATT Server callback function type. - Parameters
- event: : Event type
- gatts_if: : GATT server access interface, normally different gatts_if correspond to different profile
- param: : Point to callback parameter, currently is union type
 
 
Enumerations¶
- 
enum esp_gatts_cb_event_t¶
- GATT Server callback function events. - Values: - 
ESP_GATTS_REG_EVT= 0¶
- When register application id, the event comes 
 - 
ESP_GATTS_READ_EVT= 1¶
- When gatt client request read operation, the event comes 
 - 
ESP_GATTS_WRITE_EVT= 2¶
- When gatt client request write operation, the event comes 
 - 
ESP_GATTS_EXEC_WRITE_EVT= 3¶
- When gatt client request execute write, the event comes 
 - 
ESP_GATTS_MTU_EVT= 4¶
- When set mtu complete, the event comes 
 - 
ESP_GATTS_CONF_EVT= 5¶
- When receive confirm, the event comes 
 - 
ESP_GATTS_UNREG_EVT= 6¶
- When unregister application id, the event comes 
 - 
ESP_GATTS_CREATE_EVT= 7¶
- When create service complete, the event comes 
 - 
ESP_GATTS_ADD_INCL_SRVC_EVT= 8¶
- When add included service complete, the event comes 
 - 
ESP_GATTS_ADD_CHAR_EVT= 9¶
- When add characteristic complete, the event comes 
 - 
ESP_GATTS_ADD_CHAR_DESCR_EVT= 10¶
- When add descriptor complete, the event comes 
 - 
ESP_GATTS_DELETE_EVT= 11¶
- When delete service complete, the event comes 
 - 
ESP_GATTS_START_EVT= 12¶
- When start service complete, the event comes 
 - 
ESP_GATTS_STOP_EVT= 13¶
- When stop service complete, the event comes 
 - 
ESP_GATTS_CONNECT_EVT= 14¶
- When gatt client connect, the event comes 
 - 
ESP_GATTS_DISCONNECT_EVT= 15¶
- When gatt client disconnect, the event comes 
 - 
ESP_GATTS_OPEN_EVT= 16¶
- When connect to peer, the event comes 
 - 
ESP_GATTS_CANCEL_OPEN_EVT= 17¶
- When disconnect from peer, the event comes 
 - 
ESP_GATTS_CLOSE_EVT= 18¶
- When gatt server close, the event comes 
 - 
ESP_GATTS_LISTEN_EVT= 19¶
- When gatt listen to be connected the event comes 
 - 
ESP_GATTS_CONGEST_EVT= 20¶
- When congest happen, the event comes 
 - 
ESP_GATTS_RESPONSE_EVT= 21¶
- When gatt send response complete, the event comes 
 - 
ESP_GATTS_CREAT_ATTR_TAB_EVT= 22¶
- When gatt create table complete, the event comes 
 - 
ESP_GATTS_SET_ATTR_VAL_EVT= 23¶
- When gatt set attr value complete, the event comes 
 - 
ESP_GATTS_SEND_SERVICE_CHANGE_EVT= 24¶
- When gatt send service change indication complete, the event comes 
 
-