Well, I just copied the program from your post, copied it to the IDE and it compiled without any problem.
It would help in copying the program if you posted it in code tags like this
/*
* Control DC motor with Smartphone via bluetooth
*/
int motorPin1 = 3; // pin 2 on L293D IC
int motorPin2 = 4; // pin 7 on L293D IC
int enablePin = 5; // pin 1 on L293D IC
char state;
boolean messagePrinted = false; //makes sure that the serial only prints once the state
unsigned long currentTime; //current time used throughout the program
unsigned long startTime; //start time of period used throughout the program
unsigned long period = 200; //change this to alter the run period
boolean timing = false; //flag to indicate that timing is in progress
void setup()
{
// sets the pins as outputs:
pinMode(motorPin1, OUTPUT);
pinMode(motorPin2, OUTPUT);
pinMode(enablePin, OUTPUT);
// sets enablePin high so that motor can turn on:
digitalWrite(enablePin, HIGH);
// initialize serial communication at 9600 bits per second:
Serial.begin(9600);
}
void loop()
{
currentTime = millis(); //current time
//if some date is sent, reads it and saves in state
if (Serial.available() > 0)
{
state = Serial.read();
messagePrinted = false;;
// if the state is '0' the DC motor will turn off
if (state == '0')
{
showState();
motorStop("state 0"); //stop the motor
if (!messagePrinted)
{
Serial.println("Motor: off");
messagePrinted = true;
}
}
// if the state is '1' the motor will turn right
else if (state == '1')
{
showState();
motorRight("state 1"); //turn motor to the right
startTime = currentTime; //start time of 1 second period **************
timing = true;
Serial.println("timing");
if (!messagePrinted)
{
Serial.println("Motor: right");
messagePrinted = true;
}
}
// if the state is '2' the motor will turn left
else if (state == '2')
{
showState();
motorLeft("state 2"); //turn the motor to the left
startTime = currentTime; //start time of timing period **************
timing = true;
Serial.println("timing");
if (!messagePrinted)
{
Serial.println("Motor: left");
messagePrinted = true;
}
}
}
if (timing) //check whether period has ended
{
if (currentTime - startTime >= period) //period has ended
{
timing = false;
motorStop("timing ended");
}
}
}
void motorStop(char * source)
{
Serial.println("in motorStop()");
Serial.print("Called from : ");
Serial.println(source);
digitalWrite(motorPin1, LOW); // set pin 2 on L293D low turn off the motor
digitalWrite(motorPin2, LOW); // set pin 7 on L293D low
}
void motorRight(char * source)
{
Serial.println("in motorRight()");
Serial.print("Called from : ");
Serial.println(source);
digitalWrite(motorPin1, LOW); // set pin 2 on L293D low
digitalWrite(motorPin2, HIGH); // set pin 7 on L293D high
}
void motorLeft(char * source)
{
Serial.println("in motorLeft()");
Serial.print("Called from : ");
Serial.println(source);
digitalWrite(motorPin1, HIGH); // set pin 2 on L293D high
digitalWrite(motorPin2, LOW); // set pin 7 on L293D low
}
void showState()
{
Serial.print("State : ");
Serial.println(state);
}
What happens if you just comment out the test section rather than deleting it ?
What OS, Arduino and IDE version are you using ?
Have you got anything connected to pins 0 and 1 ?