Motors on arduino robot not working

Other Hardware Robotics
1

I am trying to recreate a project I found on Youtube for school. This is the link to the video:

I have everything connected like in the video except I am using a different motor driver.

When I connect to the arduino with my phone the motors will not work when I type in any of the commands I set. Also on the app, the text doesn't work right when I type in "w" to test it. If I were to press "w" two times, it would just keep saying stop and it wouldn't go onto a new line. Since I am still pretty new to this, I'm not sure if it is a problem with the program or the motors themselves. When I tested them they worked, so I know they aren't broken. Here is the program (I tried to copy it as best I could from the video):

int LmotorUp = 10;
int LmotorDn = 11;
int RmotorUp = 8;
int RmotorDn = 9;


void setup()
{
  Serial.begin(9600);
  pinMode(LmotorUp,OUTPUT);
  pinMode(LmotorDn,OUTPUT);
  pinMode(RmotorUp,OUTPUT);
  pinMode(RmotorDn,OUTPUT);
  Serial.print("I am a robot");
  delay(500);
  Serial.print("I move acording to the keys on your phone");
}
void loop()
{
  if (Serial.available()>0)
  {
    int input = Serial.read();
    switch(input)
    {
      case 'w' : MoveF();
      break;
      case 's' : MoveB();
      break;
      case 'a' : MoveL();
      break;
      case 'd' : MoveR();
      break;
      case 'x' : Stop();
      break;
      default : break;
    }
  }
  delay(50);
}

void MoveF()
{
  Serial.print("Move Forward");
  digitalWrite(LmotorUp,HIGH);
  digitalWrite(LmotorDn,LOW);
  digitalWrite(RmotorUp,HIGH);
  digitalWrite(RmotorDn,LOW);
}

void MoveB()
{
  Serial.print("Move Backward");
  digitalWrite(LmotorUp,LOW);
  digitalWrite(LmotorDn,HIGH);
  digitalWrite(RmotorUp,LOW);
  digitalWrite(RmotorDn,HIGH);
}

void MoveL()
{
  Serial.print("Move Left");
  digitalWrite(LmotorUp,LOW);
  digitalWrite(LmotorDn,LOW);
  digitalWrite(RmotorUp,HIGH);
  digitalWrite(RmotorDn,LOW);
}

void MoveR()
{
  Serial.print("P.E.T.E.R. Move Left");
  digitalWrite(LmotorUp,HIGH);
  digitalWrite(LmotorDn,LOW);
  digitalWrite(RmotorUp,LOW);
  digitalWrite(RmotorDn,LOW);
}

void Stop()
{
  Serial.print("Stop");
  digitalWrite(LmotorUp,LOW);
  digitalWrite(LmotorDn,LOW);
  digitalWrite(RmotorUp,LOW);
  digitalWrite(RmotorDn,LOW);
}

If anyone is able to help, then I thank you.

2

Hi!

If you use a different motor driver you have to change the addresses in your sketch !

3

What do you mean change the addresses in the sketch? :o

4 
int LmotorUp = 10;
int LmotorDn = 11;
int RmotorUp = 8;
int RmotorDn = 9;

This has to fit with your motor driver !