BlueZ5.45 D-Bus总线 GATT API 分析

最新推荐文章于 2025-03-18 14:39:40 发布

代码搬运工@@

最新推荐文章于 2025-03-18 14:39:40 发布

阅读量8.1k

点赞数

分类专栏： linux开发 ble蓝牙文章标签： linux

本文链接：https://blog.youkuaiyun.com/csdn_zyp2015/article/details/73089380

版权

笔者目前做linux系统下bluez蓝牙项目开发，发现网上关于bluez开发的资料很少。对于刚开始接触bluez蓝牙的开发人员来说是非常痛苦的。通过调试bluez源码自带的应用例子和文档说明，对BlueZ5.45 D-Bus总线 GATT API有了一些感悟。笔者不才，愿意将所了解到的一些知识分享给大家，希望能带给大家一些帮助。

一、首先看一下gatt-api说明文档，路径如下：Bluez-5.45/doc/gatt-api.txt

1、Service hierarchy

外部应用首先要用GattManager1中的注册方法注册该服务才能使本地服务生效，而且使这些方法和属性生效，还要在GattService1 接口声明，以下是gatt-api.txt文档中关于Service hierarchy说明

Service org.bluez

Interface org.bluez.GattService1

Object path   [variable prefix]/{hci0,hci1,...}/dev_XX_XX_XX_XX_XX_XX/serviceXX
Properties   string UUID [read-only]
           128-bit service UUID.
       boolean Primary [read-only]
           Indicates whether or not this GATT service is a
           primary service. If false, the service is secondary.
       object Device [read-only, optional]
           Object path of the Bluetooth device the service
           belongs to. Only present on services from remote
           devices.
       array{object} Includes [read-only]: Not implemented
           Array of object paths representing the included
           services of this service.

为了便于理解以gatt-service.c文档为例说明：

程序开始定义了以下接口：

#define GATT_MGR_IFACE           "org.bluez.GattManager1"
#define GATT_SERVICE_IFACE       "org.bluez.GattService1"
#define GATT_CHR_IFACE           "org.bluez.GattCharacteristic1"
#define GATT_DESCRIPTOR_IFACE       "org.bluez.GattDescriptor1"

其中GATT_SERVICE_IFACE为org.bluez.GattService1接口

然后定义了服务uuid和对应的特征值uuid

/* Immediate Alert Service UUID */
#define IAS_UUID           "ea816b5a-129c-4941-8a20-1c2ae3239f02"
#define ALERT_LEVEL_CHR_UUID       "7df357bb-4f53-49c0-861e-84aa2be57f65"
#define UPDATE_CHR_UUID       "b5635b6e-02cb-4fe8-a4a2-3c0279f53755"

其中#define IAS_UUID "ea816b5a-129c-4941-8a20-1c2ae3239f02"为服务uuid

然后创建和注册该服务：

create_services()->service_path = register_service(IAS_UUID)->g_dbus_register_interface(connection, path, GATT_SERVICE_IFACE,
NULL, NULL, service_properties,
g_strdup(uuid), g_free)

为该服务注册两个特征值：

/* Add Alert Level Characteris