电子键盘钢琴，程序自带四首歌曲及可调式音调、速度等，同时自带歌曲可进行速度调试。-Electronic keyboard piano, the program comes with four songs, and adjustable pitch, velocity, etc., while the speed comes songs can debug.

可调式电子密码锁，基于单片机和8段数码管，可以实现时和分的调节-Adjustable electronic password lock, based on single-chip microcomputer and 8 segment digital tube, can realize the adjustment of time and time