以下是一个基于bluez-5.50版本的样例工程代码，用于在ARM开发板上实现一个支持蓝牙5.0和可读写的GATT服务器。

#include <bluetooth/bluetooth.h>
#include <bluetooth/gatt.h>

static uint8_t value = 0;

static void read_callback(GDBusConnection *conn, const gchar *sender, const gchar *path,
                          const gchar *interface, const gchar *property, GVariant *value,
                          GError **error, gpointer user_data)
{
    g_variant_get(value, "(y)", &value);
}

static void write_callback(GDBusConnection *conn, const gchar *sender, const gchar *path,
                           const gchar *interface, const gchar *property, GVariant *value,
                           GError **error, gpointer user_data)
{
    g_variant_get(value, "(y)", &value);

    // 处理收到的写入数据

    // 发送信号通知属性值已更新
    g_dbus_connection_emit_signal(conn,
                                  NULL,
                                  path,
                                  "org.freedesktop.DBus.Properties",
                                  "PropertiesChanged",
                                  g_variant_new("(sa{sv}as)",
                                                "org.bluez.GattCharacteristic1",
                                                g_variant_new_array(NULL, NULL, 0),
                                                NULL),
                                  NULL);
}

int main()
{
    GMainLoop* loop;
    GDBusObjectManagerServer* manager;
    char uuid[] = "0000xxxx-0000-1000-8000-00805F9B34FB"; // 替换为你自己的UUID

    loop = g_main_loop_new(NULL, FALSE);

    // 初始化D-Bus连接
    if (!g_dbus_init())
        return -1;

    // 创建D-Bus对象管理器
    manager = g_dbus_object_manager_server_new("/org/bluez/example");

    // 创建GATT服务
    GDBusObjectSkeleton* service_skeleton = g_dbus_object_skeleton_new("/org/bluez/example/service");
    GattService1* service_proxy = gatt_service1_skeleton_new();
    
    // 设置GATT服务UUID
    GVariant* uuid_variant = g_variant_new_string(uuid);
    gatt_service1_set_uuid(service_proxy, uuid_variant);
    
    // 添加GATT特征值
    GDBusObjectSkeleton* characteristic_skeleton = g_dbus_object_skeleton_new("/org/bluez/example/characteristic");
    GattCharacteristic1* characteristic_proxy = gatt_characteristic1_skeleton_new();

    // 设置GATT特征值UUID
    GVariant* char_uuid_variant = g_variant_new_string("0000yyyy-0000-1000-8000-00805F9B34FB"); // 替换为你自己的UUID
    gatt_characteristic1_set_uuid(characteristic_proxy, char_uuid_variant);

    // 设置GATT特征值Flags，这里设置为Read和Write属性
    guint flags = GATT_CHARACTERISTIC_FLAGS_READ | GATT_CHARACTERISTIC_FLAGS_WRITE;
    gatt_characteristic1_set_flags(characteristic_proxy, flags);

    // 设置GATT特征值Value和Length属性，这里假设value变量是一个uint8_t类型的全局变量
    const gchar value_str[2] = {(char)value, '\0'};
    GBytes *gvalue_bytes = g_bytes_new(value_str, sizeof(value_str));
    
    if (gvalue_bytes != NULL)
        gatt_characteristic1_set_value(characteristic_proxy, (guchar *)g_bytes_get_data(gvalue_bytes, NULL), g_bytes_get_size(gvalue_bytes));

    // 注册GATT特征值的Read和Write回调函数
    gatt_characteristic1_set_read_value_callback(characteristic_proxy, read_callback, NULL);
    gatt_characteristic1_set_write_value_callback(characteristic_proxy, write_callback, NULL);

    // 将GATT特征值添加到GATT服务中
    GDBusObject* characteristic_object = G_DBUS_OBJECT(characteristic_skeleton);
    g_dbus_object_manager_server_export(manager, characteristic_object);
    
    gatt_service1_add_characteristics(service_proxy, characteristic_skeleton);

    // 添加GATT服务到D-Bus对象管理器中
    GDBusObject* service_object = G_DBUS_OBJECT(service_skeleton);
    g_dbus_object_manager_server_export(manager, service_object);

    gatt_manager1_set_default_adapter(manager);  // 设置默认适配器

    // 启动D-Bus事件循环
    g_main_loop_run(loop);

    return 0;
}

请注意，这只是一个简单的样例代码，需要根据你的具体需求进行修改和完善。确保正确设置UUID、特征值的读写属性以及相应的回调函数。另外，还需要安装bluez开发库，并在编译时链接对应的库文件。

希望这个示例对你有所帮助！


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