1. #define m1 5  //Right Motor MA1
2. #define m2 4  //Right Motor MA2
3. #define m3 2  //Left Motor MB1
4. #define m4 3  //Left Motor MB2
5. #define e1 11  //Right Motor Enable Pin EA
6. #define e2 10 //Left Motor Enable Pin EB
7.  
8. //**********5 Channel IR Sensor Connection**********//
9. #define ir1 A1
10. #define ir2 A2
11. #define ir3 A3
12. #define ir4 A4
13. #define ir5 A5
14. //*************************************************//
15.  
16. int speed = 150;
17.  
18. void setup() {
19.   pinMode(m1, OUTPUT);
20.   pinMode(m2, OUTPUT);
21.   pinMode(m3, OUTPUT);
22.   pinMode(m4, OUTPUT);
23.   pinMode(e1, OUTPUT);
24.   pinMode(e2, OUTPUT);
25.   pinMode(ir1, INPUT);
26.   pinMode(ir2, INPUT);
27.   pinMode(ir3, INPUT);
28.   pinMode(ir4, INPUT);
29.   pinMode(ir5, INPUT);
30.  
31.   CarTest();
32. }
33.  
34. void loop() {
35.   //Reading Sensor Values
36.   int s1 = digitalRead(ir1);  //Left Most Sensor
37.   int s2 = digitalRead(ir2);  //Left Sensor
38.   int s3 = digitalRead(ir3);  //Middle Sensor
39.   int s4 = digitalRead(ir4);  //Right Sensor
40.   int s5 = digitalRead(ir5);  //Right Most Sensor
41.  
42.   //if only middle sensor detects black line
43.   if((s1 == 1) && (s2 == 1) && (s3 == 0) && (s4 == 1) && (s5 == 1))
44.   {
45.     //going forward with full speed
46.     Forward(speed);
47.   }
48.  
49.   //if only left sensor detects black line
50.   if((s1 == 1) && (s2 == 0) && (s3 == 1) && (s4 == 1) && (s5 == 1))
51.   {
52.     //going right with full speed
53.     Right(speed);
54.   }
55.  
56.   //if only left most sensor detects black line
57.   if((s1 == 0) && (s2 == 1) && (s3 == 1) && (s4 == 1) && (s5 == 1))
58.   {
59.     //going right with full speed
60.     Right(speed);
61.   }
62.  
63.   //if only right sensor detects black line
64.   if((s1 == 1) && (s2 == 1) && (s3 == 1) && (s4 == 0) && (s5 == 1))
65.   {
66.     //going left with full speed
67.     Left(speed);
68.   }
69.  
70.   //if only right most sensor detects black line
71.   if((s1 == 1) && (s2 == 1) && (s3 == 1) && (s4 == 1) && (s5 == 0))
72.   {
73.     //going left with full speed
74.     Left(speed);
75.   }
76.  
77.   //if middle and right sensor detects black line
78.   if((s1 == 1) && (s2 == 1) && (s3 == 0) && (s4 == 0) && (s5 == 1))
79.   {
80.     //going left with full speed
81.     Left(speed);
82.   }
83.  
84.   //if middle and left sensor detects black line
85.   if((s1 == 1) && (s2 == 0) && (s3 == 0) && (s4 == 1) && (s5 == 1))
86.   {
87.     //going right with full speed
88.     Right(speed);
89.   }
90.  
91.   //if middle, left and left most sensor detects black line
92.   if((s1 == 0) && (s2 == 0) && (s3 == 0) && (s4 == 1) && (s5 == 1))
93.   {
94.     //going right with full speed
95.     Right(speed);
96.   }
97.  
98.   //if middle, right and right most sensor detects black line
99.   if((s1 == 1) && (s2 == 1) && (s3 == 0) && (s4 == 0) && (s5 == 0))
100.   {
101.     //going left with full speed
102.     Left(speed);
103.   }
104.  
105.   //if all sensors are on a black line
106.   if((s1 == 0) && (s2 == 0) && (s3 == 0) && (s4 == 0) && (s5 == 0))
107.   {
108.     //stop
109.     Stop();
110.   }
111.  
112.   delay(100);
113. }
114.  
115. void Forward(int speed){
116.   analogWrite(e1, speed); //you can adjust the speed of the motors from 0-255
117.   analogWrite(e2, speed); //you can adjust the speed of the motors from 0-255
118.   digitalWrite(m1, HIGH);
119.   digitalWrite(m2, LOW);
120.   digitalWrite(m3, HIGH);
121.   digitalWrite(m4, LOW);
122. }
123.  
124. void Backward(int speed){
125.   analogWrite(e1, speed); //you can adjust the speed of the motors from 0-255
126.   analogWrite(e2, speed); //you can adjust the speed of the motors from 0-255
127.   digitalWrite(m1, LOW);
128.   digitalWrite(m2, HIGH);
129.   digitalWrite(m3, LOW);
130.   digitalWrite(m4, HIGH);
131. }
132.  
133. void Right(int speed){
134.   analogWrite(e1, speed); //you can adjust the speed of the motors from 0-255
135.   analogWrite(e2, speed); //you can adjust the speed of the motors from 0-255
136.   digitalWrite(m1, HIGH);
137.   digitalWrite(m2, LOW);
138.   digitalWrite(m3, LOW);
139.   digitalWrite(m4, LOW);
140. }
141.  
142. void Left(int speed){
143.   analogWrite(e1, speed); //you can adjust the speed of the motors from 0-255
144.   analogWrite(e2, speed); //you can adjust the speed of the motors from 0-255
145.   digitalWrite(m1, LOW);
146.   digitalWrite(m2, LOW);
147.   digitalWrite(m3, HIGH);
148.   digitalWrite(m4, LOW);
149. }
150.  
151. void Stop(){
152.   digitalWrite(m1, LOW);
153.   digitalWrite(m2, LOW);
154.   digitalWrite(m3, LOW);
155.   digitalWrite(m4, LOW);
156. }
157.  
158.  
159. void CarTest(){
160.   Forward(150);
161.   delay(1000);
162.   Backward(150);
163.   delay(1000);
164.   Right(150);
165.   delay(1000);
166.   Left(150);
167.   delay(1000);
168.   Stop();
169.   delay(1000);
170. }