Robot-Niki

#include <SoftWareSerial.h>

#define M11 5
#define M12 6
#define M21 9
#define M22 10

SoftwareSerial bt(3, 4); // RX, TX
int msg;

void setup(){
   bt.begin(9600);
   pinMode(M11, OUTPUT);
   pinMode(M12, OUTPUT);
   pinMode(M21, OUTPUT);
   pinMode(M22, OUTPUT);
}

void loop(){
  if(bt.available() > 0){
     msg = bt.read();
     switch (msg){
        case 'F': forward(); break;
        case 'B': backward(); break;
        case 'L': left(); break;
        case 'R': right(); break;
        default: stop(); break;
     }
  }
  delay(10);
}


void forward(){
  digitalWrite(M11, HIGH);
  digitalWrite(M12, LOW);
  digitalWrite(M21, HIGH);
  digitalWrite(M21, LOW);
}


void forward(){
  digitalWrite(M11, HIGH);
  digitalWrite(M12, LOW);
  digitalWrite(M21, HIGH);
  digitalWrite(M21, LOW);
}


void backward(){
  digitalWrite(M11, LOW);
  digitalWrite(M12, HIGH);
  digitalWrite(M21, LOW);
  digitalWrite(M21, HIGH);
}


void left(){
  digitalWrite(M11, LOW);
  digitalWrite(M12, HIGH);
  digitalWrite(M21, HIGH);
  digitalWrite(M21, LOW);
}


void right(){
  digitalWrite(M11, HIGH);
  digitalWrite(M12, LOW);
  digitalWrite(M21, LOW);
  digitalWrite(M21, HIGH);
}

void stopp(){
  digitalWrite(M11, LOW);
  digitalWrite(M12, LOW);
  digitalWrite(M21, LOW);
  digitalWrite(M21, LOW);
}