Bluetooth Steering wheel for a robot using 1Sheeld

/*
   Bumper robot code written by: Kristian Blåsol 6/9/2015 kristian@borgstedt.com
   Original BYJ48 Stepper motor code written By :Mohannad Rawashdeh 28/9/2013, Rewritten for use with a 595 Shift Register instead by Kristian Blåsol 16/9/2015.

   Version 0.1 was without the 595
   
   Version 0.2 added a 74HC595: This program is for making a really simple (and cheap) "first" robot to play with Arduino. It is a bumper robot. This particular version
   Uses a 74HC595 to drive the Two motors, 28BYJ-48. This minimizes the pins used for the motors, from the original 8 to three for both motors in this
   Sketch.

   Version 0.2a is this code with 1Sheeld Accelerometer for turning functionality of the robot.
   
   An
   See more on
   Youtube: http://youtu.be/WwCGWTMs0Bs (version 0.2a)
   or
   Duinos.net: http://duinos.net/show/?id=238 (version 0.2a)
*/

#define CUSTOM_SETTINGS
#define INCLUDE_ACCELEROMETER_SENSOR_SHIELD

#include <OneSheeld.h>

int latchPin = 2; //pin 12 on the 595
int dataPin = 3;  //pin 14 on the 595
int clockPin = 4; //pin 11 on the 595
int ledPin = 13;

#define leftBumper 8
#define rightBumper 9

int stepper1val;
int stepper2val;
int Steps1 = 0;
int Steps2 = 0;
int wheelL = 0;
int wheelR = 0;
int AndroidAngle = 0;
//defaults to forward
boolean Direction1 = false;// gre
boolean Direction2 = true;// gre
//dir1=1 dir2=0 goes backwards
//dir1=1 dir2=1 turns right
//dir1=0 dir2=0 turns left
//dir1=0 dir2=1 goes forward

unsigned long last_time;
unsigned long currentMillis ;
int steps_left1=4095; //4095 is a whole rotation
int steps_left2=4095; //4095 is a whole rotation
long time;


void setup()
{
  OneSheeld.begin();
  pinMode(latchPin, OUTPUT);
  pinMode(dataPin, OUTPUT);  
  pinMode(clockPin, OUTPUT);  
  pinMode(ledPin, OUTPUT); 
}

void loop()
{

    AndroidAngle=AccelerometerSensor.getY();
    //wheelL=map(AndroidAngle, -9, 0, 0, 4);
    //wheelR=map(AndroidAngle, 9, 0, 0, 4);
    
    //check bumpers
    int readLeft = digitalRead(leftBumper);
    int readRight = digitalRead(rightBumper);    
   if (readLeft == HIGH) {
     back();     
     turnRight();
    } //if readLeft = HIGH
    if (readRight == HIGH) {
       back();
       turnLeft();
    } //if readRight=HIGH

    //STEP1 for moving forward
    currentMillis = micros();
    if(currentMillis-last_time>=1000) {
      //moving forward
      //defaults to moving forward
      Direction1 = false;
      Direction2 = true;
        if (AndroidAngle>-4) {stepper1(1);}
        if (AndroidAngle<4) {stepper2(1);}
        digitalWrite(latchPin, LOW);
        shiftOut(dataPin, clockPin, MSBFIRST, stepper1val+stepper2val);
        digitalWrite(latchPin, HIGH);
        time=time+micros()-last_time;
        last_time=micros();
    }
    //STEP2 for steering
    currentMillis = micros();
    if(currentMillis-last_time>=1000){
      //moving forward
      //defaults to moving forward
      Direction1 = false;
      Direction2 = true;
        if (AndroidAngle>-6) {stepper1(1);}
        if (AndroidAngle<6) {stepper2(1);}
        digitalWrite(latchPin, LOW);
        //if (AndroidAngle>-6) {shiftOut(dataPin, clockPin, MSBFIRST, stepper1val);}
        //if (AndroidAngle<6) {shiftOut(dataPin, clockPin, MSBFIRST, stepper2val);}
        shiftOut(dataPin, clockPin, MSBFIRST, stepper1val+stepper2val);
        digitalWrite(latchPin, HIGH);
        time=time+micros()-last_time;
        last_time=micros();
    }



  
} //void loop

void back(){
  //back up a bit
     steps_left1=1024;
     steps_left2=1024;
    while(steps_left1>0){
       //dir1=1 dir2=0 goes backwards
       Direction1 = true;
       Direction2 = false;
       currentMillis = micros();
      if(currentMillis-last_time>=1000){
        stepper1(1); 
        stepper2(1);
        digitalWrite(latchPin, LOW);
        shiftOut(dataPin, clockPin, MSBFIRST, stepper1val+stepper2val);
        digitalWrite(latchPin, HIGH); 
        time=time+micros()-last_time;
        last_time=micros();
        steps_left1--;
        steps_left2--;
      }
    }
}

void turnRight() {
  //turn right
      steps_left1=1024;
      steps_left2=1024;
      //dir1=1 dir2=1 turns right
    while(steps_left1>0){
       Direction1 = true;
       Direction2 = true;
       currentMillis = micros();
      if(currentMillis-last_time>=1000){
        stepper1(1); 
        stepper2(1); 
        digitalWrite(latchPin, LOW);
        shiftOut(dataPin, clockPin, MSBFIRST, stepper1val+stepper2val);
        digitalWrite(latchPin, HIGH);
        time=time+micros()-last_time;
        last_time=micros();
        steps_left1--;
        steps_left2--;
      }     
    }
}

void turnLeft() {
  //turn left
      steps_left1=1024;
      steps_left2=1024;
      //dir1=0 dir2=0 turns left
    while(steps_left1>0){
       Direction1 = false;
       Direction2 = false;
       currentMillis = micros();
      if(currentMillis-last_time>=1000){
        stepper1(1); 
        stepper2(1); 
        digitalWrite(latchPin, LOW);
        shiftOut(dataPin, clockPin, MSBFIRST, stepper1val+stepper2val);
        digitalWrite(latchPin, HIGH);
        time=time+micros()-last_time;
        last_time=micros();
        steps_left1--;
        steps_left2--;
      }     
    }
}

// motor 1 is 1 2 4 8
void stepper1(int xw){
  for (int x=0;x<xw;x++){
switch(Steps1){
   case 0:
     stepper1val=8;    
   break; 
   case 1:
     stepper1val=12;
   break; 
   case 2:
     stepper1val=4;
   break; 
   case 3:
     stepper1val=6;
   break; 
   case 4:
     stepper1val=2;
   break; 
   case 5:
     stepper1val=3;
   break; 
     case 6:
     stepper1val=1;
   break; 
   case 7:
     stepper1val=9;
   break; 
   default:
     stepper1val=0;
   break; 
}
SetDirection1();
}
} 

// 16 32 64 128
void stepper2(int xw){
  for (int x=0;x<xw;x++){
switch(Steps2){
   case 0:
     stepper2val=128;
   break; 
   case 1:
     stepper2val=192;
   break; 
   case 2:
     stepper2val=64;
   break; 
   case 3:
     stepper2val=96;
   break; 
   case 4:
     stepper2val=32;
   break; 
   case 5:
     stepper2val=48;
   break; 
     case 6:
     stepper2val=16;
   break; 
   case 7:
     stepper2val=144;
   break; 
   default:
     stepper2val=8;
   break; 
}
SetDirection2();
}
}


void SetDirection1(){
if(Direction1==1){ Steps1++;}
if(Direction1==0){ Steps1--; }
if(Steps1>7){Steps1=0;}
if(Steps1<0){Steps1=7; }
}
void SetDirection2(){
if(Direction2==1){ Steps2++;}
if(Direction2==0){ Steps2--; }
if(Steps2>7){Steps2=0;}
if(Steps2<0){Steps2=7; }
}