int pin[8]={2,3,4,5,6,7,8};
int steps[][4] =
{
{HIGH,HIGH,LOW,LOW},
{HIGH,LOW,LOW,HIGH},
{LOW,LOW,HIGH,HIGH},
{LOW,HIGH,HIGH,LOW},
} ;
int current=1;
int type=3;
int place=0;

int lastLockState = LOW;
long lastLockTime = 0;
int LockState;
int Lockreading;
bool lock=true;

int lastReturnState = LOW;
long lastReturnTime = 0;
int ReturnState;
int Returnreading;

void setup() {
for (int num=0; num<5; num++) pinMode(pin[num],OUTPUT);
for (int num=5; num<7; num++) pinMode(pin[num],INPUT);
}

void reset(){
for(int num=0;num<4;num++) digitalWrite(pin[num],LOW);
}

void stepper()
{
for (int num=0; num<4;num++) { digitalWrite(pin[num],steps[abs(type-current)][num]);} if(type==0) {++place;} if(type==3) {--place;} delay(2); } void button1() { Lockreading = digitalRead(pin[5]); if (Lockreading != lastLockState) { lastLockTime = millis(); } if ((millis() - lastLockTime) > 50)
{
if (Lockreading != LockState) {
LockState = Lockreading;
if (LockState == HIGH) {
lock=false;
if ((place!=1024*4)&&(place!=512*4)) {type=abs(type-3);}
}
}
}
lastLockState = Lockreading;
}

void button2()
{
Returnreading = digitalRead(pin[6]);
if (Returnreading != lastReturnState)
{
lastReturnTime = millis();
}
if ((millis() - lastReturnTime) > 50)
{
if (Returnreading != ReturnState) {
ReturnState = Returnreading;
if (ReturnState == HIGH) {
type=3;
digitalWrite(pin[4],HIGH);
while (place>0)
{
for (int num=0; num<4;num++) {
digitalWrite(pin[num],steps[3-current][num]);}
--place;
if (current==3) {current=0;}
else ++current;
delay(2);
}
digitalWrite(pin[4],LOW);
reset();
}
}
}
lastReturnState = Returnreading;
}

void loop() {
if (lock==true) {button1();button2();}
if (lock==false) {stepper();}
if ((place==2048*4)or(place==0)or(((place==1024*4)or(place==512*4))and(type==3))){lock=true;reset();}
if (current==3) {current=0;}
else ++current;
}