Arduino Motion-controlled Dot Matrix Display

/*
 * Arduino Motion-controlled Dot Matrix Display
 *
 * 1 Sept 2017
 * learnelectronics
 *
 * www.youtube.com/c/learnelectronics
 * arduino0169@gmail.com
 *
 * LedControl library can be found here: https://github.com/wayoda/LedControl
 * More info: https://wayoda.github.io/LedControl/pages/software
 */






#include "LedControl.h"                           //library to control 8x8 led modules w/max7219 chip


LedControl lc=LedControl(12,11,10,1);             //create instance of LedControl called lc
                                                  //arduino pin 12 -> DIN
                                                  //arduino pin 11 -> CLK
                                                  //arduino pin 10 -> LOAD(CS)
                                                  //number of modules in use


int a[5],k=0,rno=0;                               //variables

unsigned long delayTime=200;                      //int variable for milisecond wait time

byte invader1a[] =
{
   B00011000,                                     // First frame of invader #1
   B00111100,
   B01111110,
   B11011011,
   B11111111,
   B00100100,
   B01011010,
   B10100101
};

byte invader1b[] =
{
  B00011000,                                      // Second frame of invader #1
  B00111100,
  B01111110,
  B11011011,
  B11111111,
  B00100100,
  B01011010,
  B01000010
};

byte invader2a[] =
{
  B00100100,                                      // First frame of invader #2
  B00100100,
  B01111110,
  B11011011,
  B11111111,
  B11111111,
  B10100101,
  B00100100
};

byte invader2b[] =
{
  B00100100,                                      // Second frame of invader #2
  B10100101,
  B11111111,
  B11011011,
  B11111111,
  B01111110,
  B00100100,
  B01000010
};

void lister(){                                    //  Makes a stack of the analog input from A0
  for (k=0;k<4;k++){
    a[k]=a[k+1];
   }
  a[4]=analogRead(A0)/75;
  Serial.print("Input = ");
  Serial.println(a[4]);
 delay(100);
 }

int check(){                                      // Checks all the values in the stack and returns 1 if any value is different
  int flag=0;
  for(k=0;k<4;k++){
    if(a[k]!=a[k+1]){
      flag=1;
      break;
    }

  }
  return(flag);
}

void sinvader1a()                                 // Draws frame one from invader #1
{
  for (int i = 0; i < 8; i++)
  {
    lc.setColumn(0,i,invader1a[i]);
  }
}

void sinvader1b()                                 // Draws frame two from invader #1
{
  for (int i = 0; i < 8; i++)
  {
    lc.setColumn(0,i,invader1b[i]);
  }
}

void sinvader2a()                                 // Draws frame one from invader #2
{
  for (int i = 0; i < 8; i++)
  {
    lc.setColumn(0,i,invader2a[i]);
  }
}

void sinvader2b()                                 // Draws frame two from invader #2
{
  for (int i = 0; i < 8; i++)
  {
    lc.setColumn(0,i,invader2b[i]);
  }
}

void setup(){
  lc.setIntensity(0,5);                           // Set intensity level
  lc.clearDisplay(0);                             // Clear Display
}

void disp(long sel){                              // Displays invader depending on the arguments recived
  if(sel==1){
    sinvader1a();
    delay(delayTime);
    sinvader1b();
    delay(delayTime);
    }
    if(sel==2){
    sinvader2a();
    delay(delayTime);
    sinvader2b();
    delay(delayTime);
    }
  }

void loop(){

  int inc=-1,test;
  lister();
  test=check();
  Serial.print("Test = ");
  Serial.println(test);
  if (test==1){
    lc.shutdown(0,false);                         //Turns on the display
    disp(rno);
    }
   else{

    if(rno==0||rno==1)
     inc=-inc;

     rno=rno+inc;
     lc.shutdown(0,true);                         // Turns off the display
    }
}