Motoren Ansteuerung mit Arduino Seeeduino atmega168

#include <SoftwareSerial.h>

int bluetoothTx = 7;

int bluetoothRx = 5;

int M1 = 3;              //   Vorne Links

int M2 = 9;              //   Vorne Rechts

int M3 = 10;             //   Hinten Links

int M4 = 11;             //   Hinten Rechts

int zdM1=0;

int zdM2=0;

int zdM3=0;

int zdM4=0;

int x1 = 0;

int x2 = 0;

int x3 = 0;

int x4 = 0;

int b;

int bWert;

int x = 0;

int befehlsWert = 0;

int befehl = 0;         //    0 - Drehzahl

                        //    1 - Vorwärts

                        //    2 - Rückwärts

                        //    3 - Links

                        //    4 - Rechts

                        //    5 - Drehen Links

                        //    6 - Drehen Rechts

                        //    7 - KameraSerbo

SoftwareSerial bluetooth(bluetoothTx, bluetoothRx);

void setup()

{

  //Setup usb serial connection to computer

  Serial.begin(9600);

  //Setup Bluetooth serial connection to android

  bluetooth.begin(115200);

  bluetooth.print("$$$");

  delay(100);

  bluetooth.println("U,9600,N");

  bluetooth.begin(9600);

}

void loop()

{

  //Read from bluetooth and write to usb serial

  if(bluetooth.available())

  {

    char toSend = (char)bluetooth.read();

    x = toSend;

    if(x < 0)               // Korrektur des empfangenen Signal

    {

      x = 255 + x;

    }

    if(x>120)

    {

      x = x+1;

    }

    if(x>0)

    {

    //infoZerlegen(x);

    //Serial.println(x);

    b = x % 10;

    bWert = x/10;

    //Serial.println(b);

    if(b == 0){x = bWert*10;}                         //GAS

    if(b == 1){zdM3 = bWert; zdM4 = bWert;}           //Vor

    if(b == 2){zdM1 = bWert; zdM2 = bWert;}           //Zurueck

    if(b == 3){zdM2 = bWert; zdM4 = bWert;}           //Links

    if(b == 4){zdM1 = bWert; zdM3 = bWert;}           //Rechts

    x1  =   x + zdM1;

    x2  =   x + zdM2;

    x3  =   x + zdM3;

    x4  =   x + zdM4;

    analogWrite(M1,x1);

    analogWrite(M2,x1);

    analogWrite(M3,x1);

    analogWrite(M4,x1);

    }

    delay(100);

  }

  //Read from usb serial to bluetooth

  if(Serial.available())

  {

    char toSend = (char)Serial.read();

    bluetooth.print(toSend);

  }

}