给单片机初学的经验（包括电子琴，电子琴,闪烁灯,模拟开关灯,00－59秒计时器,动态数码显示技术,×4矩阵式键盘识别拉幕式数码显示技术 ,“叮咚”门铃）-To the microcontroller beginner s experience (including keyboard, organ, flashing lights, analog switches light ,00-59-second timer, dynamic digital display technology, × 4 matrix keyboard identification pull screen digital display technology, "ding dong" doorbell)