新闻中心

EEPW首页 > 嵌入式系统 > 设计应用 > 51单片机倒计时发声器

51单片机倒计时发声器

作者：时间：2016-12-01 来源：网络

设计要求: 1：上电后二位数码管显示88
2：单击按钮，倒计时开始从20秒开始，到0时喇叭发声。
3：双击按钮开关：倒计时从0开始正常记时，到20秒后发声。
4：记数结束从开始状态重新开始下一轮.

基本器件和管脚:

1)数码管:

2)74译码器 SN 74LS47

将BCD 码转换成数码管显示的数.

单片机及其接口电路:

程序代码: 本次晶振12MHZ

<a href='https://ad.eepw.com.cn/www/delivery/ck.php?n=a7a83b30&cb=INSERT_RANDOM_NUMBER_HERE' target='_blank'><img src='https://ad.eepw.com.cn/www/delivery/avw.php?zoneid=114&cb=INSERT_RANDOM_NUMBER_HERE&n=a7a83b30' border='0' alt='' /></a>
<a href='https://ad.eepw.com.cn/www/delivery/ck.php?n=a3d98779&cb=INSERT_RANDOM_NUMBER_HERE' target='_blank'><img src='https://ad.eepw.com.cn/www/delivery/avw.php?zoneid=115&cb=INSERT_RANDOM_NUMBER_HERE&n=a3d98779' border='0' alt='' /></a>
<a href='https://ad.eepw.com.cn/www/delivery/ck.php?n=abca108c&cb=INSERT_RANDOM_NUMBER_HERE' target='_blank'><img src='https://ad.eepw.com.cn/www/delivery/avw.php?zoneid=116&cb=INSERT_RANDOM_NUMBER_HERE&n=abca108c' border='0' alt='' /></a>
<a href='https://ad.eepw.com.cn/www/delivery/ck.php?n=a1775170&cb=INSERT_RANDOM_NUMBER_HERE' target='_blank'><img src='https://ad.eepw.com.cn/www/delivery/avw.php?zoneid=117&cb=INSERT_RANDOM_NUMBER_HERE&n=a1775170' border='0' alt='' /></a>
<a href='https://ad.eepw.com.cn/www/delivery/ck.php?n=a449048b&cb=INSERT_RANDOM_NUMBER_HERE' target='_blank'><img src='https://ad.eepw.com.cn/www/delivery/avw.php?zoneid=118&cb=INSERT_RANDOM_NUMBER_HERE&n=a449048b' border='0' alt='' /></a>

关键词： 51单片机倒计时发声

关闭