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 A0
10. #define ir2 A1
11. #define ir3 A2
12. #define ir4 A3
13. #define ir5 A4
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.  
32. void loop() {
33.   //Reading Sensor Values
34.   int s1 = digitalRead(ir1);  //Left Most Sensor
35.   int s2 = digitalRead(ir2);  //Left Sensor
36.   int s3 = digitalRead(ir3);  //Middle Sensor
37.   int s4 = digitalRead(ir4);  //Right Sensor
38.   int s5 = digitalRead(ir5);  //Right Most Sensor
39.  
40.   //if only middle sensor detects black line
41.   if((s1 == 1) && (s2 == 1) && (s3 == 0) && (s4 == 1) && (s5 == 1))
42.   {
43.     //going forward with full speed
44.     analogWrite(e1, speed); //you can adjust the speed of the motors from 0-255
45.     analogWrite(e2, speed); //you can adjust the speed of the motors from 0-255
46.     digitalWrite(m1, HIGH);
47.     digitalWrite(m2, LOW);
48.     digitalWrite(m3, HIGH);
49.     digitalWrite(m4, LOW);
50.   }
51.  
52.   //if only left sensor detects black line
53.   if((s1 == 1) && (s2 == 0) && (s3 == 1) && (s4 == 1) && (s5 == 1))
54.   {
55.     //going right with full speed
56.     analogWrite(e1, speed); //you can adjust the speed of the motors from 0-255
57.     analogWrite(e2, speed); //you can adjust the speed of the motors from 0-255
58.     digitalWrite(m1, HIGH);
59.     digitalWrite(m2, LOW);
60.     digitalWrite(m3, LOW);
61.     digitalWrite(m4, LOW);
62.   }
63.  
64.   //if only left most sensor detects black line
65.   if((s1 == 0) && (s2 == 1) && (s3 == 1) && (s4 == 1) && (s5 == 1))
66.   {
67.     //going right with full speed
68.     analogWrite(e1, speed); //you can adjust the speed of the motors from 0-255
69.     analogWrite(e2, speed); //you can adjust the speed of the motors from 0-255
70.     digitalWrite(m1, HIGH);
71.     digitalWrite(m2, LOW);
72.     digitalWrite(m3, LOW);
73.     digitalWrite(m4, HIGH);
74.   }
75.  
76.   //if only right sensor detects black line
77.   if((s1 == 1) && (s2 == 1) && (s3 == 1) && (s4 == 0) && (s5 == 1))
78.   {
79.     //going left with full speed
80.     analogWrite(e1, speed); //you can adjust the speed of the motors from 0-255
81.     analogWrite(e2, speed); //you can adjust the speed of the motors from 0-255
82.     digitalWrite(m1, LOW);
83.     digitalWrite(m2, LOW);
84.     digitalWrite(m3, HIGH);
85.     digitalWrite(m4, LOW);
86.   }
87.  
88.   //if only right most sensor detects black line
89.   if((s1 == 1) && (s2 == 1) && (s3 == 1) && (s4 == 1) && (s5 == 0))
90.   {
91.     //going left with full speed
92.     analogWrite(e1, speed); //you can adjust the speed of the motors from 0-255
93.     analogWrite(e2, speed); //you can adjust the speed of the motors from 0-255
94.     digitalWrite(m1, LOW);
95.     digitalWrite(m2, HIGH);
96.     digitalWrite(m3, HIGH);
97.     digitalWrite(m4, LOW);
98.   }
99.  
100.   //if middle and right sensor detects black line
101.   if((s1 == 1) && (s2 == 1) && (s3 == 0) && (s4 == 0) && (s5 == 1))
102.   {
103.     //going left with full speed
104.     analogWrite(e1, speed); //you can adjust the speed of the motors from 0-255
105.     analogWrite(e2, speed); //you can adjust the speed of the motors from 0-255
106.     digitalWrite(m1, LOW);
107.     digitalWrite(m2, LOW);
108.     digitalWrite(m3, HIGH);
109.     digitalWrite(m4, LOW);
110.   }
111.  
112.   //if middle and left sensor detects black line
113.   if((s1 == 1) && (s2 == 0) && (s3 == 0) && (s4 == 1) && (s5 == 1))
114.   {
115.     //going right with full 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, LOW);
121.     digitalWrite(m4, LOW);
122.   }
123.  
124.   //if middle, left and left most sensor detects black line
125.   if((s1 == 0) && (s2 == 0) && (s3 == 0) && (s4 == 1) && (s5 == 1))
126.   {
127.     //going right with full speed
128.     analogWrite(e1, speed); //you can adjust the speed of the motors from 0-255
129.     analogWrite(e2, speed); //you can adjust the speed of the motors from 0-255
130.     digitalWrite(m1, HIGH);
131.     digitalWrite(m2, LOW);
132.     digitalWrite(m3, LOW);
133.     digitalWrite(m4, LOW);
134.   }
135.  
136.   //if middle, right and right most sensor detects black line
137.   if((s1 == 1) && (s2 == 1) && (s3 == 0) && (s4 == 0) && (s5 == 0))
138.   {
139.     //going left with full speed
140.     analogWrite(e1, speed); //you can adjust the speed of the motors from 0-255
141.     analogWrite(e2, speed); //you can adjust the speed of the motors from 0-255
142.     digitalWrite(m1, LOW);
143.     digitalWrite(m2, LOW);
144.     digitalWrite(m3, HIGH);
145.     digitalWrite(m4, LOW);
146.   }
147.  
148.   //if all sensors are on a black line
149.   if((s1 == 0) && (s2 == 0) && (s3 == 0) && (s4 == 0) && (s5 == 0))
150.   {
151.     //stop
152.     digitalWrite(m1, LOW);
153.     digitalWrite(m2, LOW);
154.     digitalWrite(m3, LOW);
155.     digitalWrite(m4, LOW);
156.   }
157. }