主要围绕HC-05蓝牙模块的主从连接来实现U盘的防丢功能。在该设计中首先对两个HC-05蓝牙模块进行主从设置,使它们能够在上电后自动验证密码,当密码正确时则进行配对连接,密码错误则拒绝连接,防止其他蓝牙模块的干扰。当主从两个蓝牙模块之间物理距离在所设定的15米范围内,报警电路不输出报警信息。超过15米范围,蓝牙主模块与从模块之间的信号连接将会中断,蓝牙主模块检测不到从模块所发出连接信息,蓝牙主模块将会给继电器模块发出高电平信号,驱动继电器模块动作,使继电器模块的常开触点吸合,进而为单片机提供5V电源,单片机开始得电运行并通过P1.0口输出高电平来驱动蜂鸣器发出警报声,从而实现防丢的目的。 Mainly around the HC-05 Bluetooth module master-slave connection to achieve U disk anti-lost function. The design of the first two HC-05 Bluetooth module master and slave settings, so that they can automatically verify the password after power-on, when the password is correct, the connection is paired, the wrong password is refused to connect to prevent interference from other Bluetooth modules . When the master-slave two Bluetooth module physical distance between the set within 15 meters, the alarm circuit does not output alarm information. Over 15 meters, the signal connection between the Bluetooth master module and the slave module will be interrupted. The Bluetooth master module can not detect the connection information sent from the module. The Bluetooth master module will send a high signal to the relay module to drive the relay module Action, so that the normally open contact relay module pull-in, and then provide 5V power supply for the microcontroller, the microcontroller began to run and electricity through the P1.0 port output high to drive the buzzer sounded the alarm, so as to achieve the purpose of anti-lost .