安防声光报警器：自制一个单片机最小系统，包括串口下载、复位电路，采用两路外部中断输入门禁和红外探测两路信号（采用两个小按键模拟），中断信号输入后能将报警信息在四位一体数码管上显示，并输出声光报警信号。-Security sound and light alarm: a homemade smallest single-chip system, including the serial download, reset circuit, using two external interrupt inputs Access and infrared detection two signals (using two small buttons analog), the input signal can interrupt the alarm message four in one digital display on the tube, and output sound and light alarm signal.