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# Controller & HCI

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## API Reference

### Header File

- components/bt/include/esp32h4/include/esp_bt.h

- This header file can be included with:

  >     #include "esp_bt.h"

- This header file is a part of the API provided by the `bt` component. To declare that your component depends on `bt`, add the following to your CMakeLists.txt:

  >     REQUIRES bt

  > or

  >     PRIV_REQUIRES bt

### Functions

esp_err_t esp_bt_controller_init(esp_bt_controller_config_t *cfg)

  Initialize BT controller to allocate task and other resource. This function should be called only once, before any other BT functions are called.

  Parameters:

    cfg -- Initial configuration of BT controller. Different from previous version, there's a mode and some connection configuration in "cfg" to configure controller work mode and allocate the resource which is needed.

  Returns:

    ESP_OK - success, other - failed

esp_bt_controller_status_t esp_bt_controller_get_status(void)

  Get BT controller is initialised/de-initialised/enabled/disabled.

  Returns:

    status value

esp_err_t esp_bt_controller_deinit(void)

  De-initialize BT controller to free resource and delete task. You should stop advertising and scanning, as well as disconnect all existing connections before de-initializing BT controller.

  This function should be called only once, after any other BT functions are called. This function is not whole completed, esp_bt_controller_init cannot called after this function.

  Returns:

    ESP_OK - success, other - failed

esp_err_t esp_bt_controller_enable(esp_bt_mode_t mode)

  Enable BT controller. Due to a known issue, you cannot call esp_bt_controller_enable() a second time to change the controller mode dynamically. To change controller mode, call esp_bt_controller_disable() and then call esp_bt_controller_enable() with the new mode.

  Parameters:

    mode -- : the mode(BLE/BT/BTDM) to enable. For compatible of API, retain this argument. This mode must be equal as the mode in "cfg" of esp_bt_controller_init().

  Returns:

    ESP_OK - success, other - failed

esp_err_t esp_bt_controller_disable(void)

  Disable BT controller.

  Returns:

    ESP_OK - success, other - failed

bool esp_vhci_host_check_send_available(void)

  esp_vhci_host_check_send_available used for check actively if the host can send packet to controller or not.

  Returns:

    true for ready to send, false means cannot send packet

void esp_vhci_host_send_packet(uint8_t *data, uint16_t len)

  esp_vhci_host_send_packet host send packet to controller

  Should not call this function from within a critical section or when the scheduler is suspended.

  Parameters:

    - data -- the packet point

    - len -- the packet length

esp_err_t esp_vhci_host_register_callback(const esp_vhci_host_callback_t *callback)

  esp_vhci_host_register_callback register the vhci reference callback struct defined by vhci_host_callback structure.

  Parameters:

    callback -- esp_vhci_host_callback type variable

  Returns:

    ESP_OK - success, ESP_FAIL - failed

esp_err_t esp_bt_controller_mem_release(esp_bt_mode_t mode)

  esp_bt_controller_mem_release release the controller memory as per the mode

  This function releases the BSS, data and other sections of the controller to heap. The total size is about 70k bytes.

  esp_bt_controller_mem_release(mode) should be called only before esp_bt_controller_init() or after esp_bt_controller_deinit().

  Note that once BT controller memory is released, the process cannot be reversed. It means you cannot use the bluetooth mode which you have released by this function.

  If your firmware will later upgrade the Bluetooth controller mode (BLE -> BT Classic or disabled -> enabled) then do not call this function.

  If the app calls esp_bt_controller_enable(ESP_BT_MODE_BLE) to use BLE only then it is safe to call esp_bt_controller_mem_release(ESP_BT_MODE_CLASSIC_BT) at initialization time to free unused BT Classic memory.

  If the mode is ESP_BT_MODE_BTDM, then it may be useful to call API esp_bt_mem_release(ESP_BT_MODE_BTDM) instead, which internally calls esp_bt_controller_mem_release(ESP_BT_MODE_BTDM) and additionally releases the BSS and data consumed by the BT/BLE host stack to heap. For more details about usage please refer to the documentation of esp_bt_mem_release() function

  Parameters:

    mode -- : the mode want to release memory

  Returns:

    ESP_OK - success, other - failed

esp_err_t esp_bt_mem_release(esp_bt_mode_t mode)

  esp_bt_mem_release release controller memory and BSS and data section of the BT/BLE host stack as per the mode

  This function first releases controller memory by internally calling esp_bt_controller_mem_release(). Additionally, if the mode is set to ESP_BT_MODE_BTDM, it also releases the BSS and data consumed by the BT/BLE host stack to heap

  Note that once BT memory is released, the process cannot be reversed. It means you cannot use the bluetooth mode which you have released by this function.

  If your firmware will later upgrade the Bluetooth controller mode (BLE -> BT Classic or disabled -> enabled) then do not call this function.

  If you never intend to use bluetooth in a current boot-up cycle, you can call esp_bt_mem_release(ESP_BT_MODE_BTDM) before esp_bt_controller_init or after esp_bt_controller_deinit.

  For example, if a user only uses bluetooth for setting the WiFi configuration, and does not use bluetooth in the rest of the product operation". In such cases, after receiving the WiFi configuration, you can disable/deinit bluetooth and release its memory. Below is the sequence of APIs to be called for such scenarios:

       esp_bluedroid_disable();
       esp_bluedroid_deinit();
       esp_bt_controller_disable();
       esp_bt_controller_deinit();
       esp_bt_mem_release(ESP_BT_MODE_BTDM);

  Parameters:

    mode -- : the mode whose memory is to be released

  Returns:

    ESP_OK - success, other - failed

int esp_ble_hw_get_static_addr(esp_ble_addr_t *addr)

  Returns random static address or -1 if not present.

  Returns:

    ESP_OK - success, other - failed

### Structures

struct esp_ble_addr_t

  Address type and address value.

  Public Members

  uint8_t type

    Type of the Bluetooth address (public, random, etc.)

  uint8_t val[6]

    Array containing the 6-byte Bluetooth address value

struct esp_bt_ctrl_btdm_config_t

  BTDM controller common configuration options.

  Public Members

  uint32_t version

    Version number of the defined structure

  uint16_t task_stack_size

    Size of Bluetooth controller task stack

  uint8_t task_prio

    Priority of the Bluetooth controller task

  uint8_t task_run_cpu

    CPU number on which the Bluetooth controller task runs

  uint8_t hci_cmd_num

    HCI command buffer number

  uint8_t sleep_en

    Enable sleep functionality

  uint8_t version_num

    Hardware version number of this chip

  uint8_t bluetooth_mode

    Controller mode: BR/EDR, BLE or Dual Mode

  uint32_t magic

    Magic number for configuration validation

struct esp_bt_controller_config_t

  Controller config options, depend on config mask. Config mask indicate which functions enabled, this means some options or parameters of some functions enabled by config mask.

  Public Members

  esp_bt_ctrl_le_config_t ble

    Bluetooth LE controller configuration options

  esp_bt_ctrl_btdm_config_t btdm

    Bluetooth controller common configuration options

struct esp_vhci_host_callback

  esp_vhci_host_callback used for vhci call host function to notify what host need to do

  Public Members

  void (*notify_host_send_available)(void)

    callback used to notify that the host can send packet to controller

  int (*notify_host_recv)(uint8_t *data, uint16_t len)

    callback used to notify that the controller has a packet to send to the host

### Macros

BTDM_CONFIG_VERSION

BTDM_CONFIG_MAGIC_VALUE

BTDM_CONTROLLER_MODE_EFF

BT_CONTROLLER_INIT_CONFIG_DEFAULT()

### Type Definitions

typedef enum esp_ble_power_type esp_ble_power_type_t

typedef enum esp_power_level esp_power_level_t

typedef struct esp_vhci_host_callback esp_vhci_host_callback_t

  esp_vhci_host_callback used for vhci call host function to notify what host need to do

### Enumerations

enum esp_bt_mode_t

  Bluetooth mode for controller enable/disable.

  Values:

  enumerator ESP_BT_MODE_IDLE

    Bluetooth is not running

  enumerator ESP_BT_MODE_BLE

    Run BLE mode

  enumerator ESP_BT_MODE_CLASSIC_BT

    Run Classic BT mode

  enumerator ESP_BT_MODE_BTDM

    Run dual mode

enum esp_bt_controller_status_t

  Bluetooth controller enable/disable/initialised/de-initialised status.

  Values:

  enumerator ESP_BT_CONTROLLER_STATUS_IDLE

    Controller is in idle state

  enumerator ESP_BT_CONTROLLER_STATUS_INITED

    Controller is in initialising state

  enumerator ESP_BT_CONTROLLER_STATUS_ENABLED

    Controller is in enabled state

  enumerator ESP_BT_CONTROLLER_STATUS_NUM

    Controller is in disabled state

enum esp_ble_power_type

  BLE tx power type ESP_BLE_PWR_TYPE_CONN_HDL0-8: for each connection, and only be set after connection completed. when disconnect, the correspond TX power is not effected. ESP_BLE_PWR_TYPE_ADV : for advertising/scan response. ESP_BLE_PWR_TYPE_SCAN : for scan. ESP_BLE_PWR_TYPE_DEFAULT : if each connection's TX power is not set, it will use this default value. if neither in scan mode nor in adv mode, it will use this default value. If none of power type is set, system will use ESP_PWR_LVL_P3 as default for ADV/SCAN/CONN0-9.

  Values:

  enumerator ESP_BLE_PWR_TYPE_CONN_HDL0

    For connection handle 0

  enumerator ESP_BLE_PWR_TYPE_CONN_HDL1

    For connection handle 1

  enumerator ESP_BLE_PWR_TYPE_CONN_HDL2

    For connection handle 2

  enumerator ESP_BLE_PWR_TYPE_CONN_HDL3

    For connection handle 3

  enumerator ESP_BLE_PWR_TYPE_CONN_HDL4

    For connection handle 4

  enumerator ESP_BLE_PWR_TYPE_CONN_HDL5

    For connection handle 5

  enumerator ESP_BLE_PWR_TYPE_CONN_HDL6

    For connection handle 6

  enumerator ESP_BLE_PWR_TYPE_CONN_HDL7

    For connection handle 7

  enumerator ESP_BLE_PWR_TYPE_CONN_HDL8

    For connection handle 8

  enumerator ESP_BLE_PWR_TYPE_ADV

    For advertising

  enumerator ESP_BLE_PWR_TYPE_SCAN

    For scan

  enumerator ESP_BLE_PWR_TYPE_DEFAULT

    For default, if not set other, it will use default value

  enumerator ESP_BLE_PWR_TYPE_NUM

    TYPE numbers

enum esp_power_level

  Bluetooth TX power level(index), it's just a index corresponding to power(dbm).

  Values:

  enumerator ESP_PWR_LVL_N24

    Corresponding to -24dbm

  enumerator ESP_PWR_LVL_N21

    Corresponding to -21dbm

  enumerator ESP_PWR_LVL_N18

    Corresponding to -18dbm

  enumerator ESP_PWR_LVL_N15

    Corresponding to -15dbm

  enumerator ESP_PWR_LVL_N12

    Corresponding to -12dbm

  enumerator ESP_PWR_LVL_N9

    Corresponding to -9dbm

  enumerator ESP_PWR_LVL_N6

    Corresponding to -6dbm

  enumerator ESP_PWR_LVL_N3

    Corresponding to -3dbm

  enumerator ESP_PWR_LVL_N0

    Corresponding to 0dbm

  enumerator ESP_PWR_LVL_P3

    Corresponding to +3dbm

  enumerator ESP_PWR_LVL_P6

    Corresponding to +6dbm

  enumerator ESP_PWR_LVL_P9

    Corresponding to +9dbm

  enumerator ESP_PWR_LVL_P12

    Corresponding to +12dbm

  enumerator ESP_PWR_LVL_P15

    Corresponding to +15dbm

  enumerator ESP_PWR_LVL_P16

    Corresponding to +16dbm

  enumerator ESP_PWR_LVL_P17

    Corresponding to +17dbm

  enumerator ESP_PWR_LVL_P18

    Corresponding to +18dbm

  enumerator ESP_PWR_LVL_P19

    Corresponding to +19dbm

  enumerator ESP_PWR_LVL_P20

    Corresponding to +20dbm

  enumerator ESP_PWR_LVL_INVALID

    Indicates an invalid value

## HCI Vendor-specific (VS) Commands

Espressif's HCI VS commands are exclusively designed for use with Espressif's Bluetooth Host stack or internal debugging purposes. Application developers should not initialize or invoke these VS commands in their applications. Please refer to HCI Vendor-specific (VS) Commands for detailed information.

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