* 十字路口红绿灯控制器 *

* 第一个状态：主干道、支干道均亮红灯5S 　　　　*

* 第二个状态：主干道亮绿灯30S、支干道亮红灯 　　　　*

* 第三个状态：主干道绿灯闪3次转亮黄灯、支干道亮红灯3S 　　　　*

* 第四个状态：主干道亮红灯、支干道亮绿灯25S 　　　　*

* 第五个状态：主干道亮红灯、支干道绿灯闪3次转亮黄灯3S 　　　　*

* 返回到第二个状态 　　　　*- * Crossroads traffic light controller* * The first one states: trunk, branch roads are red flag, 5S* * The second states: trunk light green 30S, branch roads red light* * The third-state : main road turn bright green light flashing three times yellow, branch roads red light 3S* * The fourth state: trunk red light, green light sticks roads 25S* * the fifth state: trunk red light , branch roads turn bright green light flashing three times yellow 3S* * to return to the second state*