此方法是我用4*5矩阵键盘时候想到的，采用了中断检测方法，释放了CPU等待时间，加强OS实时性。此算法和电路经验证简单可行，仅以简单的51单片机做例子.-This method is what I use 4* 5 matrix keyboard ever think of, using the interrupt detection methods, the release of CPU wait time, strengthen the real-time OS. This algorith