蓝牙概述

蓝牙基础架构

蓝牙分为 BT Host、HCI (Host Controller Interface) 和 BT Controller 三部分:

模块		描述
BT Host	Application	包含蓝牙 APIs，以及由此实现的 Peripheral、Central、Scatternet、Mesh、A2DP、LE Audio 等应用
	Framework	包含以下 lib： LE audio lib：\component\bluetooth\rtk_stack\platform\amebaxxx\lib\(km4\kr4\ca32)\leaudio.a BLE mgr lib：\component\bluetooth\rtk_stack\platform\amebaxxx\lib\(km4\kr4\ca32)\ble_mgr.a BT mgr lib：\component\bluetooth\rtk_stack\platform\amebaxxx\lib\(km4\kr4\ca32)\bt_mgr.a system lib：\component\bluetooth\rtk_stack\platform\amebaxxx\lib\(km4\kr4\ca32)\sysm.a 各 lib 的作用： LE audio lib & BLE mgr lib：实现了 BAP 和 CAP，以及 LE audio 依赖的 BLE profile BT mgr lib：实现了 BR/EDR profile system lib：提供一些系统相关的功能
	Host stack	lib 路径：\component\bluetooth\rtk_stack\platform\amebaxxx\lib\(km4\kr4\ca32)\(ble_only\dual_mode)\btgap.a 实现了蓝牙上层协议栈的功能，包括 GAP、GATT、L2CAP、ATT 和 SMP 等
HCI		Controller 与 Host 唯一的通信接口，两者之间的所有数据交互都通过该接口完成
BT Controller		lib 路径：\component\bluetooth\driver\platform\amebaxxx\hci\bt_normal_patch.c 以二进制数组形式提供，实现了蓝牙下层协议栈的功能，包括 Link Layer 和 PHY

蓝牙的基础架构如下图所示：

蓝牙功能支持列表

RTL8721DxRTL8720ERTL8710ERTL8726ERTL8713ERTL8730ERTL8721FRTL8735C

RTL8721Dx:

Item	Feature	Supported
Physical	BR/EDR	N
	BLE	Y
BLE 4.0	Advertiser	Y
	Scanner	Y
	Initiator	Y
	Master	Y
	Slave	Y
	Link Layer Encryption	Y
	BLE Max. Link (Theoretical value)	8 Master + 3 Slave
BLE 4.1	Low Duty Cycle Directed Advertising	Y
	MWS Coexistence	N
	LE Ping	Y
	LE Link Layer Topology	Y
	LE Scatternet	Y
BLE 4.2	LE Data Length Extension	Y
	LE Secure Connection	Y
	Link Layer Privacy	Y
	Link Layer Extended Scanner Filter Policies	Y
BLE 5.0	LE 2Mbps PHY	Y
	LE Long Range	Y
	LE Advertising Extensions	Y
	LE Channel Selection Algorithm #2	Y
	High Duty Cycle Non-Connectable Advertising	Y
	LE Periodic Advertising	N

蓝牙功能配置

功能	配置文件	配置项
Link Layer Privacy	以 Peripheral 为例： \component\bluetooth\example\ble_peripheral\peripheral.c	修改 privacy_enable 为 true
LE Advertising Extensions	\component\bluetooth\api\include\bt_api_config.h	修改 RTK_BLE_5_0_AE_ADV_SUPPORT 和 RTK_BLE_5_0_AE_SCAN_SUPPORT 为 1
LE Periodic Advertising	\component\bluetooth\api\include\bt_api_config.h	修改相应 SoC 的 RTK_BLE_5_0_AE_ADV_SUPPORT，RTK_BLE_5_0_AE_SCAN_SUPPORT，RTK_BLE_5_0_PA_ADV_SUPPORT 和 RTK_BLE_5_0_PA_SYNC_SUPPORT 为 1
Periodic Advertising Sync Transfer (PAST)	\component\bluetooth\api\include\bt_api_config.h	修改相应 SoC 的 RTK_BLE_5_0_AE_ADV_SUPPORT，RTK_BLE_5_0_AE_SCAN_SUPPORT，RTK_BLE_5_0_PA_ADV_SUPPORT，RTK_BLE_5_0_PA_SYNC_SUPPORT， RTK_BLE_5_1_PAST_SENDER_SUPPORT 和 RTK_BLE_5_1_PAST_RECIPIENT_SUPPORT 为 1
SMP OOB	\component\bluetooth\api\include\bt_api_config.h	默认开启，修改 RTK_BLE_SMP_OOB_SUPPORT 为 0 关闭
LE Data Length Extension	\component\bluetooth\api\include\bt_api_config.h	默认开启，修改 RTK_BLE_4_2_DATA_LEN_EXT_SUPPORT 为 0 关闭
SET PHYS	\component\bluetooth\api\include\bt_api_config.h	默认开启，修改 RTK_BLE_5_0_SET_PHYS_SUPPORT 为 0 关闭
LE Power Control	\component\bluetooth\api\include\bt_api_config.h	修改 RTK_BLE_5_2_POWER_CONTROL_SUPPORT 为 1
EATT	\component\bluetooth\api\include\bt_api_config.h	修改 RTK_BT_5_2_EATT_SUPPORT 为 1