TIMER1与TIMER2控制十字路口秒计时显示屏 东西向蓝色数码管与南北向红色数码管同步倒计时，若干秒后交换，如此反复，仅剩5秒时，系统会发出报警提示声音-TIMER1 with TIMER2, control crossroads second chronograph display something to the blue LED with north and south toward the red end of the digital tube synchronized countd