1 int redled = 8; //红色LED 输出
 2 int yellowled = 7; //黄色LED输出
 3 int greenled = 6; //绿色LED输出
 4 int redpin = 5; //红色按键引脚
 5 int yellowpin = 4; //黄色按键引脚
 6 int greenpin = 3; //绿色按键引脚
 7 int restpin = 2; //复位按键引脚定义
 8 int red;
 9 int yellow;
10 int green;
11 void setup() {
12     pinMode(redled, OUTPUT);
13     pinMode(yellowled, OUTPUT);
14     pinMode(greenled, OUTPUT);
15     pinMode(redpin, INPUT);
16     pinMode(yellowpin, INPUT);
17     pinMode(greenpin, INPUT);
18 }
19 void loop() //按键循环扫描。
20 {
21     red = digitalRead(redpin);
22     yellow = digitalRead(yellowpin);
23     green = digitalRead(greenpin);
24     if (red == LOW) RED_YES();
25     if (yellow == LOW) YELLOW_YES();
26     if (green == LOW) GREEN_YES();
27 }
28
29 void RED_YES() //一直执行红灯亮，直到复位键按下，结束循环
30 {
31     while (digitalRead(restpin) == 1) {
32         digitalWrite(redled, HIGH);
33         digitalWrite(greenled, LOW);
34         digitalWrite(yellowled, LOW);
35     }
36     clear_led();
37 }
38 void YELLOW_YES() //一直执行黄灯亮，直到复位键按下，结束循环
39 {
40     while (digitalRead(restpin) == 1) {
41         digitalWrite(redled, LOW);
42         digitalWrite(greenled, LOW);
43         digitalWrite(yellowled, HIGH);
44     }
45     clear_led();
46 }
47 void GREEN_YES() //一直执行绿灯亮，直到复位键按下，结束循环
48 {
49     while (digitalRead(restpin) == 1) {
50         digitalWrite(redled, LOW);
51         digitalWrite(greenled, HIGH);
52         digitalWrite(yellowled, LOW);
53     }
54     clear_led();
55 }
56 void clear_led() //清除LED
57 {
58     digitalWrite(redled, LOW);
59     digitalWrite(greenled, LOW);
60     digitalWrite(yellowled, LOW);
61 }