利用PWM产生高精度正弦波,从PWM引脚输出的脉冲信号经过简单的低通滤波后,可以得到平滑的正弦波,波的频率可以微调-produced using high-precision sine wave PWM, PWM output pin from the pulse signal through simple low-pass filter, can be smooth sine wave, the wave frequency can be fine-tuned
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001403s ]
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:0.117498s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.001349s ]
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SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.000893s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.003143s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.000830s ]
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SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.015417s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.000997s ]
UPDATE `jrk_articles` SET `hits` = 2 WHERE `id` = 172403 [ RunTime:0.018688s ]