设计一个紧急控制开关信号，当紧急开关信号为1时，两个方向的灯全为红灯。紧急开关撤消后，按照开关按下之前的状态继续运行（其参数要保存）。（2）设计一个夜间行车开关，当开关按下后，两个方向都只有黄灯闪烁，其它灯熄灭。（3）设计两个方向的亮时时间可调。-Design an emergency control switch signal, when the emergency switch signal is 1, the two directions of light are all red. After withdrawal of the emergency switch, according to the state before the switch is pressed to continue to run (the parameters to be saved). (2) to design a switch driving at night, when the switch is pressed, the flashing yellow light are only two directions, the other lights off. (3) design time in both directions when the light adjustable.