蓝牙技术在嵌入式系统设计中的应用

　　蓝牙技术在嵌入式系统设计中的应用

　　提起蓝牙，非工程师首先想到的是无线耳机，它似乎从几乎所有智能手机用户的耳朵中萌芽。另一方面，嵌入式设计师看到一种低成本、互操作的、电池友好的技术，可以使他们的产品与越来越多的消费者和工业设备交换数据文件和多媒体流（图1）。在本文中，我们将探讨成功集成该技术的一些设计问题，以及新一代专门为嵌入式应用设计的蓝牙设备的体系结构和功能集。

　　Figure 1： Bluetooth， and its cousin Bluetooth low-power， provide an efficient， near-universal conduit for data between embedded applications such as glucometers （top）， blood pressure meters， or other health care equipment （bottom） and a standard smartphone or tablet computer.

　　Different profiles

　　The original Bluetooth specification¹ and all of its variants operate in the in the globally unlicensed Industrial， Scientific， and Medical （ISM） 2.4 GHz short-range band using frequency-hopping spread-spectrum transmission. Nearly all devices on the market today support the Bluetooth v1.2 specification and its 720 kbit/s data rate. Even many low-cost products also support the V2.0/V2.1 +EDR specifications， which feature improved security， simpler pairing between devices， and modes which enable reduced power consumption. The recently-introduced Bluetooth low energy specification² features dramatically-reduced power consumption at the cost of reduced data rates and shorter effective range.