脉冲宽度的测量，利用1602液晶显示，和4*4键盘输入，AT89C52单片机控制，实现对长脉冲宽度的测量-Pulse width measurement, the use of liquid crystal display 1602, and 4* 4 keyboard input, AT89C52 single-chip control, realize the long pulse width measurement
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001243s ]
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:0.087832s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001242s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.001892s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.001198s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003593s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.001042s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.003200s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.014676s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001281s ]
UPDATE `jrk_articles` SET `hits` = 1 WHERE `id` = 225788 [ RunTime:0.001198s ]
