电子钟，实现每按一次按键,显示时分秒的数码管数字均可分别加1或减1，且当显示小时的数码管显示到24时，所有数码管会自动清零。-Electronic clock to achieve every time I press the button, the display minutes and seconds can be a digital control numbers plus 1 or minus 1, respectively, and when the digital LED display shows hours to 24 hours, all the digital control will be automatically cleared.