int m1p=8;
int m1n=9;
int m2p=10;
int m2n=11;
char state;
const int trigPin = 6;
const int echoPin = 7;
int led=5;
long duration;
int distance;

void setup() {
  // put your setup code here, to run once:
  pinMode(8,OUTPUT);
  pinMode(9,OUTPUT);
  pinMode(10,OUTPUT);
pinMode(11,OUTPUT);
pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
pinMode(echoPin, INPUT); // Sets the echoPin as an Input
pinMode(led,OUTPUT);
Serial.begin(9600);
}

void loop() {

  digitalWrite(trigPin, LOW);
delayMicroseconds(2);
// Sets the trigPin on HIGH state for 10 micro seconds
digitalWrite(trigPin, HIGH);
delayMicroseconds(10);
digitalWrite(trigPin, LOW);
// Reads the echoPin, returns the sound wave travel time in microseconds
duration = pulseIn(echoPin, HIGH);
// Calculating the distance
distance= duration*0.034/2;
// Prints the distance on the Serial Monitor
/*Serial.print("Distance: ");
Serial.println(distance);*/
if (distance<=15)
{
digitalWrite(5,HIGH);
} 
else
{
  digitalWrite(5,LOW);
}
 
  // put your main code here, to run repeatedly:
  if (Serial.available()>0)
  {
    char state=Serial.read();
    if (state=='L')
    {
      digitalWrite(9,LOW);
digitalWrite(11,HIGH);
digitalWrite(8,HIGH);
digitalWrite(10,LOW);
    }
  else if (state=='R')
  {

digitalWrite(8,LOW);
digitalWrite(10,HIGH);
digitalWrite(9,HIGH);
digitalWrite(11,LOW);
  }

else if (state=='B')
{
  digitalWrite(9,LOW);
digitalWrite(8,HIGH);
digitalWrite(10,HIGH);
digitalWrite(11,LOW);
}
else if (state=='F')
{
  digitalWrite(8,LOW);
digitalWrite(9,HIGH);
digitalWrite(11,HIGH);
digitalWrite(10,LOW);
}
else 
{
  digitalWrite(8,HIGH);
digitalWrite(10,HIGH);
digitalWrite(11,HIGH);
digitalWrite(9,HIGH);
}
}
}