单片机的双精度实型数double存储格式是8个字节，当上传至后台电脑时，需要将以长整数表示形式转换成为实型数，该程序函数提供了转换方法-The single-chip double-precision real number double the storage format is 8 bytes, when uploaded to the background when the computer requires that the form will be a long integer typ

三建扫描程序，实现三个键盘的扫描，去抖动，及与后台程序的通信-three key scan ,scan the three key ,remove the error,and com with the while.