CARMAGEDDON: The Agile Arduino Car

1char command;                  
2int const directionA = 12;		   
3int  const directionB = 13;
4int const speedA = 3;		                    //A is the  left wheel, B is the right one
5int const speedB = 11;
6int const brakeA = 9;			   
7int const brakeB = 8;
8bool flagBackward;
9
10void setup() {
11  Serial.begin(9600);          
12  pinMode(directionA, OUTPUT);
13  pinMode(directionB, OUTPUT);
14  pinMode(speedA, OUTPUT);             
15  pinMode(speedB, OUTPUT);
16  pinMode(brakeA,  OUTPUT);
17  pinMode(brakeB, OUTPUT);
18}
19
20void loop() {
21
22  if (Serial.available()  > 0) {             
23
24    command = Serial.read();                 
25
26    switch (command) {
27      case ('='):                                //stop  command
28        flagBackward = false;
29        analogWrite(speedA, 0);
30        analogWrite(speedB, 0);
31        digitalWrite(brakeA, HIGH);
32        digitalWrite(brakeB,  HIGH);
33        break;
34
35      case ('F'):                               //forward  command
36        flagBackward = false;
37        digitalWrite(brakeA, LOW);	   
38        digitalWrite(brakeB, LOW);
39        digitalWrite(directionA, LOW);	
40        digitalWrite(directionB, LOW);
41        analogWrite(speedA, 255);
42        analogWrite(speedB, 255);
43        break;
44
45      case ('B'):                               //backward  command
46        flagBackward = true;
47        digitalWrite(brakeA, LOW);
48        digitalWrite(brakeB, LOW);
49        digitalWrite(directionA, HIGH);
50        digitalWrite(directionB, HIGH);
51        analogWrite(speedA, 255);
52        analogWrite(speedB, 255);
53        break;
54
55      case ('R'):                               //right  command
56        digitalWrite(brakeA, LOW);
57        digitalWrite(brakeB, HIGH);
58        if (flagBackward == false) {
59          digitalWrite(directionA, LOW);
60        } else {
61          digitalWrite(directionA, HIGH);
62        }
63        digitalWrite(directionB,  HIGH);
64        analogWrite(speedA, 255);
65        analogWrite(speedB, 0);
66        break;
67
68      case ('L'):                               //left command
69        digitalWrite(brakeA, HIGH);
70        digitalWrite(brakeB, LOW);
71        digitalWrite(directionA,  HIGH);
72        if (flagBackward == false) {
73          digitalWrite(directionB,  LOW);
74        } else {
75          digitalWrite(directionB, HIGH);
76        }
77        analogWrite(speedA, 0);
78        analogWrite(speedB, 255);
79        break;
80
81    }
82  }
83}
84