SPP API

Application Example

Check bluetooth/bluedroid/classic_bt folder in ESP-IDF examples, which contains the following application:

API Reference

Functions

esp_err_t esp_spp_register_callback(esp_spp_cb_t callback)

This function is called to init callbacks with SPP module.

Return

  • ESP_OK: success

  • other: failed

Parameters

  • [in] callback: pointer to the init callback function.

esp_err_t esp_spp_init(esp_spp_mode_t mode)

This function is called to init SPP module. When the operation is completed, the callback function will be called with ESP_SPP_INIT_EVT. This function should be called after esp_bluedroid_enable() completes successfully.

Return

  • ESP_OK: success

  • other: failed

Parameters

  • [in] mode: Choose the mode of SPP, ESP_SPP_MODE_CB or ESP_SPP_MODE_VFS.

esp_err_t esp_spp_deinit(void)

This function is called to uninit SPP module. The operation will close all active SPP connection first, then the callback function will be called with ESP_SPP_CLOSE_EVT, and the number of ESP_SPP_CLOSE_EVT is equal to the number of connection. When the operation is completed, the callback function will be called with ESP_SPP_UNINIT_EVT. This function should be called after esp_spp_init() completes successfully.

Return

  • ESP_OK: success

  • other: failed

esp_err_t esp_spp_start_discovery(esp_bd_addr_t bd_addr)

This function is called to performs service discovery for the services provided by the given peer device. When the operation is completed, the callback function will be called with ESP_SPP_DISCOVERY_COMP_EVT. This funciton must be called after esp_spp_init() successful and before esp_spp_deinit().

Return

  • ESP_OK: success

  • other: failed

Parameters

  • [in] bd_addr: Remote device bluetooth device address.

esp_err_t esp_spp_connect(esp_spp_sec_t sec_mask, esp_spp_role_t role, uint8_t remote_scn, esp_bd_addr_t peer_bd_addr)

This function makes an SPP connection to a remote BD Address. When the connection is initiated or failed to initiate, the callback is called with ESP_SPP_CL_INIT_EVT. When the connection is established or failed, the callback is called with ESP_SPP_OPEN_EVT. This funciton must be called after esp_spp_init() successful and before esp_spp_deinit().

Return

  • ESP_OK: success

  • other: failed

Parameters

  • [in] sec_mask: Security Setting Mask. Suggest to use ESP_SPP_SEC_NONE, ESP_SPP_SEC_AUTHORIZE or ESP_SPP_SEC_AUTHENTICATE only.

  • [in] role: Master or slave.

  • [in] remote_scn: Remote device bluetooth device SCN.

  • [in] peer_bd_addr: Remote device bluetooth device address.

esp_err_t esp_spp_disconnect(uint32_t handle)

This function closes an SPP connection. When the operation is completed, the callback function will be called with ESP_SPP_CLOSE_EVT. This funciton must be called after esp_spp_init() successful and before esp_spp_deinit().

Return

  • ESP_OK: success

  • other: failed

Parameters

  • [in] handle: The connection handle.

esp_err_t esp_spp_start_srv(esp_spp_sec_t sec_mask, esp_spp_role_t role, uint8_t local_scn, const char *name)

This function create a SPP server and starts listening for an SPP connection request from a remote Bluetooth device. When the server is started successfully, the callback is called with ESP_SPP_START_EVT. When the connection is established, the callback is called with ESP_SPP_SRV_OPEN_EVT. This funciton must be called after esp_spp_init() successful and before esp_spp_deinit().

Return

  • ESP_OK: success

  • other: failed

Parameters

  • [in] sec_mask: Security Setting Mask. Suggest to use ESP_SPP_SEC_NONE, ESP_SPP_SEC_AUTHORIZE or ESP_SPP_SEC_AUTHENTICATE only.

  • [in] role: Master or slave.

  • [in] local_scn: The specific channel you want to get. If channel is 0, means get any channel.

  • [in] name: Server’s name.

esp_err_t esp_spp_stop_srv(void)

This function stops all SPP servers. The operation will close all active SPP connection first, then the callback function will be called with ESP_SPP_CLOSE_EVT, and the number of ESP_SPP_CLOSE_EVT is equal to the number of connection. When the operation is completed, the callback is called with ESP_SPP_SRV_STOP_EVT. This funciton must be called after esp_spp_init() successful and before esp_spp_deinit().

Return

  • ESP_OK: success

  • other: failed

esp_err_t esp_spp_stop_srv_scn(uint8_t scn)

This function stops a specific SPP server. The operation will close all active SPP connection first on the specific SPP server, then the callback function will be called with ESP_SPP_CLOSE_EVT, and the number of ESP_SPP_CLOSE_EVT is equal to the number of connection. When the operation is completed, the callback is called with ESP_SPP_SRV_STOP_EVT. This funciton must be called after esp_spp_init() successful and before esp_spp_deinit().

Return

  • ESP_OK: success

  • other: failed

Parameters

  • [in] scn: Server channel number.

esp_err_t esp_spp_write(uint32_t handle, int len, uint8_t *p_data)

This function is used to write data, only for ESP_SPP_MODE_CB. When this function need to be called repeatedly, it is strongly recommended to call this function again after the previous event ESP_SPP_WRITE_EVT is received and the parameter ‘cong’ is equal to false. If the previous event ESP_SPP_WRITE_EVT with parameter ‘cong’ is equal to true, the function can only be called again when the event ESP_SPP_CONG_EVT with parameter ‘cong’ equal to false is received. This funciton must be called after an connection between initiator and acceptor has been established.

Return

  • ESP_OK: success

  • other: failed

Parameters

  • [in] handle: The connection handle.

  • [in] len: The length of the data written.

  • [in] p_data: The data written.

esp_err_t esp_spp_vfs_register(void)

This function is used to register VFS. For now, SPP only supports write, read and close.

Return

  • ESP_OK: success

  • other: failed

Unions

union esp_spp_cb_param_t
#include <esp_spp_api.h>

SPP callback parameters union.

Public Members

struct esp_spp_cb_param_t::spp_init_evt_param init

SPP callback param of SPP_INIT_EVT

struct esp_spp_cb_param_t::spp_uninit_evt_param uninit

SPP callback param of SPP_UNINIT_EVT

struct esp_spp_cb_param_t::spp_discovery_comp_evt_param disc_comp

SPP callback param of SPP_DISCOVERY_COMP_EVT

struct esp_spp_cb_param_t::spp_open_evt_param open

SPP callback param of ESP_SPP_OPEN_EVT

struct esp_spp_cb_param_t::spp_srv_open_evt_param srv_open

SPP callback param of ESP_SPP_SRV_OPEN_EVT

struct esp_spp_cb_param_t::spp_close_evt_param close

SPP callback param of ESP_SPP_CLOSE_EVT

struct esp_spp_cb_param_t::spp_start_evt_param start

SPP callback param of ESP_SPP_START_EVT

struct esp_spp_cb_param_t::spp_srv_stop_evt_param srv_stop

SPP callback param of ESP_SPP_SRV_STOP_EVT

struct esp_spp_cb_param_t::spp_cl_init_evt_param cl_init

SPP callback param of ESP_SPP_CL_INIT_EVT

struct esp_spp_cb_param_t::spp_write_evt_param write

SPP callback param of ESP_SPP_WRITE_EVT

struct esp_spp_cb_param_t::spp_data_ind_evt_param data_ind

SPP callback param of ESP_SPP_DATA_IND_EVT

struct esp_spp_cb_param_t::spp_cong_evt_param cong

SPP callback param of ESP_SPP_CONG_EVT

struct spp_cl_init_evt_param
#include <esp_spp_api.h>

ESP_SPP_CL_INIT_EVT.

Public Members

esp_spp_status_t status

status

uint32_t handle

The connection handle

uint8_t sec_id

security ID used by this server

bool use_co

TRUE to use co_rfc_data

struct spp_close_evt_param
#include <esp_spp_api.h>

ESP_SPP_CLOSE_EVT.

Public Members

esp_spp_status_t status

status

uint32_t port_status

PORT status

uint32_t handle

The connection handle

bool async

FALSE, if local initiates disconnect

struct spp_cong_evt_param
#include <esp_spp_api.h>

ESP_SPP_CONG_EVT.

Public Members

esp_spp_status_t status

status

uint32_t handle

The connection handle

bool cong

TRUE, congested. FALSE, uncongested

struct spp_data_ind_evt_param
#include <esp_spp_api.h>

ESP_SPP_DATA_IND_EVT.

Public Members

esp_spp_status_t status

status

uint32_t handle

The connection handle

uint16_t len

The length of data

uint8_t *data

The data received

struct spp_discovery_comp_evt_param
#include <esp_spp_api.h>

SPP_DISCOVERY_COMP_EVT.

Public Members

esp_spp_status_t status

status

uint8_t scn_num

The num of scn_num

uint8_t scn[ESP_SPP_MAX_SCN]

channel #

const char *service_name[ESP_SPP_MAX_SCN]

service_name

struct spp_init_evt_param
#include <esp_spp_api.h>

SPP_INIT_EVT.

Public Members

esp_spp_status_t status

status

struct spp_open_evt_param
#include <esp_spp_api.h>

ESP_SPP_OPEN_EVT.

Public Members

esp_spp_status_t status

status

uint32_t handle

The connection handle

int fd

The file descriptor only for ESP_SPP_MODE_VFS

esp_bd_addr_t rem_bda

The peer address

struct spp_srv_open_evt_param
#include <esp_spp_api.h>

ESP_SPP_SRV_OPEN_EVT.

Public Members

esp_spp_status_t status

status

uint32_t handle

The connection handle

uint32_t new_listen_handle

The new listen handle

int fd

The file descriptor only for ESP_SPP_MODE_VFS

esp_bd_addr_t rem_bda

The peer address

struct spp_srv_stop_evt_param
#include <esp_spp_api.h>

ESP_SPP_SRV_STOP_EVT.

Public Members

esp_spp_status_t status

status

uint8_t scn

Server channel number

struct spp_start_evt_param
#include <esp_spp_api.h>

ESP_SPP_START_EVT.

Public Members

esp_spp_status_t status

status

uint32_t handle

The connection handle

uint8_t sec_id

security ID used by this server

uint8_t scn

Server channel number

bool use_co

TRUE to use co_rfc_data

struct spp_uninit_evt_param
#include <esp_spp_api.h>

SPP_UNINIT_EVT.

Public Members

esp_spp_status_t status

status

struct spp_write_evt_param
#include <esp_spp_api.h>

ESP_SPP_WRITE_EVT.

Public Members

esp_spp_status_t status

status

uint32_t handle

The connection handle

int len

The length of the data written.

bool cong

congestion status

Macros

ESP_SPP_SEC_NONE

No security. relate to BTA_SEC_NONE in bta/bta_api.h

ESP_SPP_SEC_AUTHORIZE

Authorization required (only needed for out going connection ) relate to BTA_SEC_AUTHORIZE in bta/bta_api.h

ESP_SPP_SEC_AUTHENTICATE

Authentication required. relate to BTA_SEC_AUTHENTICATE in bta/bta_api.h

ESP_SPP_SEC_ENCRYPT

Encryption required. relate to BTA_SEC_ENCRYPT in bta/bta_api.h

ESP_SPP_SEC_MODE4_LEVEL4

Mode 4 level 4 service, i.e. incoming/outgoing MITM and P-256 encryption relate to BTA_SEC_MODE4_LEVEL4 in bta/bta_api.h

ESP_SPP_SEC_MITM

Man-In-The_Middle protection relate to BTA_SEC_MITM in bta/bta_api.h

ESP_SPP_SEC_IN_16_DIGITS

Min 16 digit for pin code relate to BTA_SEC_IN_16_DIGITS in bta/bta_api.h

ESP_SPP_MAX_MTU

SPP max MTU

ESP_SPP_MAX_SCN

SPP max SCN

Type Definitions

typedef uint16_t esp_spp_sec_t
typedef void (esp_spp_cb_t)(esp_spp_cb_event_t event, esp_spp_cb_param_t *param)

SPP callback function type. When handle ESP_SPP_DATA_IND_EVT, it is strongly recommended to cache incoming data, and process them in other lower priority application task rather than in this callback directly.

Parameters

  • event: Event type

  • param: Point to callback parameter, currently is union type

Enumerations

enum esp_spp_status_t

Values:

ESP_SPP_SUCCESS = 0

Successful operation.

ESP_SPP_FAILURE

Generic failure.

ESP_SPP_BUSY

Temporarily can not handle this request.

ESP_SPP_NO_DATA

No data

ESP_SPP_NO_RESOURCE

No more resource

ESP_SPP_NEED_INIT

SPP module shall init first

ESP_SPP_NEED_DEINIT

SPP module shall deinit first

ESP_SPP_NO_CONNECTION

Connection may have been closed

ESP_SPP_NO_SERVER

No SPP server

enum esp_spp_role_t

Values:

ESP_SPP_ROLE_MASTER = 0

Role: master

ESP_SPP_ROLE_SLAVE = 1

Role: slave

enum esp_spp_mode_t

Values:

ESP_SPP_MODE_CB = 0

When data is coming, a callback will come with data

ESP_SPP_MODE_VFS = 1

Use VFS to write/read data

enum esp_spp_cb_event_t

SPP callback function events.

Values:

ESP_SPP_INIT_EVT = 0

When SPP is inited, the event comes

ESP_SPP_UNINIT_EVT = 1

When SPP is uninited, the event comes

ESP_SPP_DISCOVERY_COMP_EVT = 8

When SDP discovery complete, the event comes

ESP_SPP_OPEN_EVT = 26

When SPP Client connection open, the event comes

ESP_SPP_CLOSE_EVT = 27

When SPP connection closed, the event comes

ESP_SPP_START_EVT = 28

When SPP server started, the event comes

ESP_SPP_CL_INIT_EVT = 29

When SPP client initiated a connection, the event comes

ESP_SPP_DATA_IND_EVT = 30

When SPP connection received data, the event comes, only for ESP_SPP_MODE_CB

ESP_SPP_CONG_EVT = 31

When SPP connection congestion status changed, the event comes, only for ESP_SPP_MODE_CB

ESP_SPP_WRITE_EVT = 33

When SPP write operation completes, the event comes, only for ESP_SPP_MODE_CB

ESP_SPP_SRV_OPEN_EVT = 34

When SPP Server connection open, the event comes

ESP_SPP_SRV_STOP_EVT = 35

When SPP server stopped, the event comes

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