单片机播放音乐 通过控制高低电平让蜂鸣器发出不同的声音 做相应的延时实现节拍
开发环境是keil-SCM music by controlling the high-low so that the buzzer sounds different delay accordingly to achieve the beat
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001075s ]
SELECT `a`.`aid`,`a`.`title`,`a`.`create_time`,`m`.`username` FROM `jrk_downrecords` `a` INNER JOIN `jrk_member` `m` ON `a`.`uid`=`m`.`id` WHERE `a`.`status` = 1 GROUP BY `a`.`aid` ORDER BY `a`.`create_time` DESC LIMIT 10 [ RunTime:0.084430s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001669s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001871s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.001732s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.005105s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.001472s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.006266s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.018267s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001346s ]
UPDATE `jrk_articles` SET `hits` = 2 WHERE `id` = 137014 [ RunTime:0.011079s ]
