按键是单片机系统最常用的输入设备之一；几乎是只要需要交互输入，就必须有键盘。本程序提供最常用的4*4矩阵键盘的程序，和4个按键的程序。 -The key is one of the most commonly used input devices MCU system it is nearly as long as the need for interactive input, it must have the keyboard.