RC car racing (Arduino interfaced)

1#include <VirtualWire.h>  // you must download and install the VirtualWire.h  to your hardware/libraries folder
2
3//Undefine unneded types
4#undef abs
5#undef  double
6#undef float
7#undef round
8
9
10//Define constants
11#define  FORWARD '8'
12#define BACKWARD '5'
13#define STOP '0'
14#define LEFT '4'
15#define  RIGHT '6'
16#define STRAIGHT '/'
17
18#define TIMEOUT 500UL
19
20//Set motor  pins
21int motor1Pin1 = 4;    // pin 2 on L293D
22   // pin 7 on L293D
23int  enablePin1 = 10;    // pin 1 on L293D
24int motor2Pin1 = 6;    // pin 10 on L293D
25    // pin 15 on L293D
26int enablePin2 = 11;    // pin 9 on L293D
27
28//motor  speed variables
29int motor1Speed = 255;
30int motor2Speed = 255;
31int angle  = 0;   // angle defined
32//Counter variable
33unsigned long counter;
34
35
36void  setup() 
37{  
38    //Set pin modes
39    pinMode(motor1Pin1, OUTPUT);
40   
41    pinMode(motor2Pin1, OUTPUT);
42   
43    
44    
45
46
47    Serial.begin(115200);
48    //Initialise the IO and ISR
49    vw_set_ptt_inverted(true);    // Required  for RX Link Module
50    vw_setup(4500);                   // Bits per sec
51    vw_set_rx_pin(13);           // We will be receiving on pin 23 (Mega) ie the  RX pin from the module connects to this pin. 
52    vw_rx_start();                      //  Start the receiver 
53}
54void loop()
55{
56   
57  //variables for Virtual  Wire
58  uint8_t buf[VW_MAX_MESSAGE_LEN];
59  uint8_t buflen = VW_MAX_MESSAGE_LEN;
60  
61  //If we got a message from the serial port
62  if (Serial.available())
63  {
64    //Reset the timeout counter
65    counter = millis();
66    //Drive  the requested motor
67    drive(Serial.read());
68    
69    //Otherwise check  for a message from the reciever
70  } else if (vw_get_message(buf, &buflen)) //  check to see if anything has been received
71    {
72      //Reset timeout counter
73      counter = millis();
74      int i;
75      Serial.println("recieved");  //Debug message
76       // Message with a good checksum received.
77      
78      
79      //For each command recieved
80      for (i = 0; i < buflen; i++)
81      {
82          drive(buf[i]); //Drive requested motors
83      }
84      
85      
86      //If the counter is greater than the timeout (No signal recieved)  then stop the car.
87    } else if(millis()-counter >= TIMEOUT) {
88      drive(STOP);
89      drive(STRAIGHT); 
90    }
91}
92
93
94//The drive function
95void drive(int  dir) {
96  //Check which direction is requested (same for below)
97  if (dir ==  FORWARD) {
98     Serial.println("Forward");//Used for debugging
99     
100       //Set motor accordingly (same for below)
101     digitalWrite(motor1Pin1,  LOW);
102     analogWrite(enablePin1, 255);
103     digitalWrite(motor2Pin1,LOW);
104     analogWrite(enablePin2, 255);
105     
106  } else if (dir == BACKWARD) {
107    Serial.println("Backward");
108     digitalWrite(motor1Pin1,HIGH);
109     analogWrite(enablePin1,  255);  
110     digitalWrite(motor2Pin1, HIGH);
111     analogWrite(enablePin2,  255);
112    
113  } else if (dir == STOP) {
114     Serial.println("Stop");
115     digitalWrite(motor1Pin1, LOW);
116     analogWrite(enablePin1, 0);  
117     digitalWrite(motor2Pin1,  LOW);
118     analogWrite(enablePin2, 0);
119  
120  } else if(dir == STRAIGHT)  {
121    Serial.println("Straight");
122     digitalWrite(motor1Pin1, HIGH);
123     analogWrite(enablePin1, 0);
124     digitalWrite(motor2Pin1, HIGH);
125     analogWrite(enablePin2,0);
126    
127  }else if (dir == LEFT) {
128    Serial.println("Left");
129     digitalWrite(motor1Pin1,  LOW);  
130     analogWrite(enablePin1, 255);
131     digitalWrite(motor2Pin1, HIGH);
132     analogWrite(enablePin2, 255);
133    
134  }else if (dir == RIGHT) {
135    Serial.println("Right");
136   digitalWrite(motor1Pin1, HIGH); 
137   analogWrite(enablePin1, 0);
138     digitalWrite(motor2Pin1,  LOW);
139     analogWrite(enablePin2, 255);
140    
141  }
142}
143
144 
145