基于单片机设计的电子琴，不仅有电子琴的基本功能，还可以播放系统自带的三首乐曲，更重要的是用户可以自制乐曲并可以断点保存。-Microcontroller-based design of the keyboard, not only the basic functions of the keyboard can also play the system comes with three music and, more importantly, the user can self-made musi