(2) Eye fatigue alert: automatic calculation of time learning to read, after reaching a certain time to remind the rest, preventing eye fatigue;

(3) automatic light test;：Test whether the light intensity can reach learning standard of reading conditions。 If the situation is too dark or too strong,it automatic alarms。

This article describes the characteristics and the application of Bluetooth 4。0 technology, summed up in the intelligent care areas of daily life in Bluetooth 4。0 has irreplaceable advantages。 At present, the research and design of the system overall program  includes the detection module, a processing module and alarm module。 

Various types of sensors for detecting the surrounding environment sampled, after analog to digital conversion into a digital signal;nRF51xx series development board's Cortex M0 information processing module。 Buzzer, red LED and the like achieve data processing and alarm around。 After clipping the back of this product by physical model design and integrated into the glasses, which can effectively help users to re-develop good habits with their eyes, reducing the use of glasses at a lot of inconvenience。 The latter can apply for related patents, it has a market value。

Key words: Bluetooth 4。0; Smart Glasses; Fatigue Warning; Wireless Communication

目   录

第一章 概论 1

1。1 课题研究背景及意义 1

1。2 国内外现状 1

1。3 课题研究内容及章节安排 2

1。3。1 课题研究内容 2

1。3。2 本文结构安排 2

第二章 蓝牙系统相关技术概述 3

2。1 蓝牙发展历程 3

2。2 蓝牙的网络结构 3

2。3 第四代蓝牙 4

2。4 低功耗 5

2。5 第四代蓝牙协议栈 6

2。5。1 控制层 7

2。5。2 主协议层 9

2。5。3 应用层 12

2。6 本章小结 12

第三章  硬件子系统的分析与设计 14

3。1 硬件选择需求分析 14

3。1。1 芯片版本对应的flash和RAM 14

3。1。2 芯片版本对应的SDK 15

3。2 nRF51822开发板 15

3。2。1 nRF51822 16

3。2。2 电源 17

3。3 Jlink下载器 18

3。4 OLED屏幕模块 18

3。5光敏传感器 19

3。6 蜂鸣器模块 21

3。7 本章小结 21

第四章 软件子系统设计与实现 23

4。1 开发环境 23

4。1。1 nRFgo Studio 23

4。1。2 Keil 23

4。1。3 蓝牙4。0协议栈 24

4。2  I/O接口输入输出 24

4。2。1 普通接口