采用 AT89C52型号的单片机对传统的电扇系统进行改造，实现对电扇的短距离控制。该设计利用单片机进行红外发送，红外接收，在此过程中对红外进行编码和解码，而后通过不同的编码形成对风扇的不同控制。同时对单片机 P0口的输出进行 DA 变换后，完成对风扇的速度的实时控制。通过仿真实验，验证了该方案的可行性，该设计简单、可靠，具有很强的实用性。
SHOW FULL COLUMNS FROM `jrk_downrecords` [ RunTime:0.001518s ]
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:0.114325s ]
SHOW FULL COLUMNS FROM `jrk_tagrecords` [ RunTime:0.004753s ]
SELECT * FROM `jrk_tagrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 20 [ RunTime:0.002118s ]
SHOW FULL COLUMNS FROM `jrk_member` [ RunTime:0.001339s ]
SELECT `id`,`username`,`userhead`,`usertime` FROM `jrk_member` WHERE `status` = 1 ORDER BY `usertime` DESC LIMIT 10 [ RunTime:0.004876s ]
SHOW FULL COLUMNS FROM `jrk_searchrecords` [ RunTime:0.001174s ]
SELECT * FROM `jrk_searchrecords` WHERE `status` = 1 ORDER BY `num` DESC LIMIT 5 [ RunTime:0.005077s ]
SELECT aid,title,count(aid) as c FROM `jrk_downrecords` GROUP BY `aid` ORDER BY `c` DESC LIMIT 10 [ RunTime:0.015505s ]
SHOW FULL COLUMNS FROM `jrk_articles` [ RunTime:0.001080s ]
UPDATE `jrk_articles` SET `hits` = 2 WHERE `id` = 549086 [ RunTime:0.018527s ]
