Bluetooth Controlled car using Arduino

#define m11 11 // rear motor
#define m12 12
#define m21 10 // front motor
#define m22 9

char str[2],i;

void forward()
{
digitalWrite(m11, LOW);
digitalWrite(m12, LOW);
digitalWrite(m21, HIGH);
digitalWrite(m22, LOW);
}

void backward()
{
digitalWrite(m11, LOW);
digitalWrite(m12, LOW);
digitalWrite(m21, LOW);
digitalWrite(m22, HIGH);
}

void left()
{
digitalWrite(m11, HIGH);
digitalWrite(m12, LOW);
delay(100);
digitalWrite(m21, HIGH);
digitalWrite(m22, LOW);
}

void right()
{
digitalWrite(m11, LOW);
digitalWrite(m12, HIGH);
delay(100);
digitalWrite(m21, HIGH);
digitalWrite(m22, LOW);
}

void Stop()
{
digitalWrite(m11, LOW);
digitalWrite(m12, LOW);
digitalWrite(m21, LOW);
digitalWrite(m22, LOW);
}

void setup()
{
Serial.begin(9600);
pinMode(m11, OUTPUT);
pinMode(m12, OUTPUT);
pinMode(m21, OUTPUT);
pinMode(m22, OUTPUT);
}

void loop()
{
while(Serial.available())
{
char ch=Serial.read();
str[i++]=ch;

if(str[i-1]==‘1’)
{
Serial.println(“Forward”);
forward();
i=0;
}

else if(str[i-1]==‘2’)
{
Serial.println(“Left”);
right();
i=0;
}

else if(str[i-1]==‘3’)
{
Serial.println(“Right”);
left();
i=0;
}

else if(str[i-1]==‘4’)
{
Serial.println(“Backward”);
backward();
i=0;
}

else if(str[i-1]==‘5’)
{
Serial.println(“Stop”);
Stop();
i=0;
}
delay(100);
}
}

...and?

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