文件名称：ESP32蓝牙架构（官方）
文件大小：1.16MB
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更新时间：2021-08-29 07:40:28
ESP32 Bluetooth FreeRtos 蓝牙 Low
ESP32 蓝牙开发资料，用于了解ESP32内部的蓝牙实现。 本⼿册为 ESP32 的蓝⽛架构简介，主要分三个章节介绍了蓝⽛、经典蓝⽛和蓝⽛低功耗 ⽅⾯的整体架构。注意，本⼿册仅针对 ESP-IDF V2.1 及以下版本。 ⽬录 1. 蓝⽛ 1 ......................................................................................................................................... 1.1. 概述 ............................................................................................................................................1 1.1.1. 蓝⽛应⽤结构 ................................................................................................................1 1.1.2. HCI 接⼝选择 ................................................................................................................2 1.1.3. 蓝⽛运⾏环境 ................................................................................................................3 1.2. 框架 ............................................................................................................................................4 1.2.1. 控制器 ...........................................................................................................................4 1.2.2. BLUEDROID .................................................................................................................4 1.2.2.1. 主机架构 ................................................................................................................4 1.2.2.2. OS 相关适配..........................................................................................................6 1.2.3. 蓝⽛⽬录........................................................................................................................6 2. 经典蓝⽛ 9 ................................................................................................................................. 2.1. 概述 ............................................................................................................................................9 2.2. 协议和规范 ...............................................................................................................................10 2.2.1. L2CAP.........................................................................................................................10 2.2.2. SDP.............................................................................................................................10 2.2.3. GAP.............................................................................................................................10 2.2.4. A2DP 和 AVRCP .........................................................................................................11 3. 蓝⽛低功耗 14 ............................................................................................................................ 3.1. GAP..........................................................................................................................................14 3.1.1. 概述.............................................................................................................................14 3.1.2. BLE 设备⻆⾊转换状态图............................................................................................15 3.1.3. BLE ⼴播流程..............................................................................................................16 3.1.3.1. 使⽤ public 地址进⾏⼴播...................................................................................16 3.1.3.2. 使⽤可解析地址进⾏⼴播....................................................................................17 3.1.3.3. 使⽤静态随机地址进⾏⼴播 ................................................................................18 3.1.4. BLE ⼴播类型介绍.......................................................................................................19 3.1.4.1. 可连接可扫描⾮定向⼴播....................................................................................19 3.1.4.2. ⾼占空⽐定向⼴播和可连接低占空⽐定向⼴播 ...................................................19 3.1.4.3. 可扫描⾮定向⼴播...............................................................................................20 3.1.4.4. 不可连接⾮定向⼴播 ...........................................................................................20 3.1.5. BLE ⼴播过滤策略介绍 ...............................................................................................20 3.1.6. BLE 扫描流程..............................................................................................................21 3.1.7. BLE GAP 实现机制 .....................................................................................................21 3.2. GATT ........................................................................................................................................21 3.2.1. ATT 属性协议 .............................................................................................................21 3.2.2. GATT 规范...................................................................................................................23 3.2.3. 基于 ESP32 IDF 建⽴ GATT 服务（GATT 服务器） ....................................................25 3.2.4. 基于 ESP32 IDF 发现对⽅设备的服务信息（GATT 客户端）......................................26 3.3. SMP .........................................................................................................................................27 3.3.1. 概述.............................................................................................................................27 3.3.2. BLE 安全管理控制器...................................................................................................27 3.3.2.1.BLE 加密流程 .......................................................................................................27 3.3.2.2.BLE 绑定流程 .......................................................................................................30 3.3.3. BLE 安全管理实现机制 .............................