tiny LED cube

The revised code:

#include <LiquidCrystal (2).h>
#include <LiquidCrystal.h>

LiquidCrystal lcd(53, 51, 41, 39, 33, 31);

//variables used:

int brightness = 175;    //used for the brightness of the LEDs
int operation;     //this will control which LED operation occurs
int previousNumber;//used to try and prevent any operation repeating twice in a row
int delayValue = 500; //this determines how long a function lasts before moving on
int i;             //this will be used in for loops and array controlls


//pin declerations:

const int TFL = 3;    //top front, left LED
const int TFR = 4;    //top front, right LED
const int TRL = 5;    //top rear, left LED
const int TRR = 6;    //top rear, right LED
const int BFL = 7;    //bottom front, left LED
const int BFR = 8;    //bottom front, right LED
const int BRL = 9;    //bottom rear, left LED
const int BRR = 10;   //bottom rear, right LED


//function prototypes for LED operations:

void top();
void bottom();
void left();
void right();
void corners1();
void corners2();
void all();


//arrays used:

char chaseTop[4] = {TFL, TFR, TRR, TRL};
char chaseBottom[4] = {BFL, BFR, BRR, BRL};
char chaseLeftSide[4] = {TFL, BFL, BRL, TRL};
char chaseRightSide[4] = {TFR, BFR, BRR, TRR};
char chaseCorners[4] = {TFR, TRL, BRL, BFR};
char chaseCorners1[4] = {TFL, TRR, BRR, BFL};




void setup(){
  lcd.begin(16,2);
  //set up the LCD so we can see what it is doing
  
  //the LED brighness pin is an analog INPUT by default.
  //As we are using it as an analog input pin, we do not need to
  //declare it's use.
  //the LED brighness pin is an analog OUTPUT by default.
  //As we are using it as an analog output pin, we do not need to
  //declare it's use.
}


void loop(){
  loops:
  
  //TURN ALL PINS OFF
  analogWrite(TFL, 0);
  analogWrite(TFR, 0);
  analogWrite(TRL, 0);
  analogWrite(TRR, 0);
  analogWrite(BFL, 0);
  analogWrite(BFR, 0);
  analogWrite(BRL, 0);
  analogWrite(BRR, 0);
  
  delay(50);
  
 // brightnessRead = analogRead(brightPin);             //read the potentiometer value on analog pin 0
 // brightness = map(brightnessRead, 0, 1023, 0, 255);  //map the brighness value from the analog reading
                                   // range of 0 - 1023 to the brightness range of 0 - 255
  randomSeed(analogRead(A7));      //pick a random place to start making random numbers from
  operation = random(1, 13);       //create a random number with a max of 13 and a min of 1. 
                                   //This will be used for choosing the LED operation.
  if(operation == previousNumber){
    goto loops;
  }
  
  else{
    
    lcd.clear();    //eraxe the current contents of the LCD to display the new contents  
  switch(operation){             
      //perform a different function depending on the value of operation
      case 1:    //if 'operation' equals 1,
      lcd.print("top()");
      analogWrite(TFR, brightness);    //turns on the top front right LED
      analogWrite(TRR, brightness);    //turns on the top back right LED
      analogWrite(TFL, brightness);    //turns on the top front left LED
      analogWrite(TRL, brightness);    //turns on the top back left LED
      delay(delayValue);
      break;         //used to close switch statement

      case 2:    //if 'operation' equals 2,
      lcd.print("bottom()");
      analogWrite(BFR, brightness);    //turns on the bottom front right LED
      analogWrite(BRR, brightness);    //turns on the bottom back right LED
      analogWrite(BFL, brightness);    //turns on the bottom front left LED
      analogWrite(BRL, brightness);    //turns on the bottom back left LED
      delay(delayValue);
      break;            //used to close switch statement
      
      case 3:          //same as above
      lcd.print("left()");
      analogWrite(TFL, brightness);    //turns on the top front left LED
      analogWrite(TRL, brightness);    //turns on the top back left LED
      analogWrite(BFL, brightness);    //turns on the top front left LED
      analogWrite(BRL, brightness);    //turns on the top back left LED
      delay(delayValue);
      break;
      
      case 4:
      lcd.print("right()");
      analogWrite(TFR, brightness);    //turns on the top front right LED
      analogWrite(TRR, brightness);    //turns on the top back right LED
      analogWrite(BFR, brightness);    //turns on the top front right LED
      analogWrite(BRR, brightness);    //turns on the top back right LED
      delay(delayValue);
      break;
      
      case 5:
      lcd.print("corners1()");
      analogWrite(TFL, brightness);    //turns on the top front left LED
      analogWrite(BRR, brightness);    //turns on the bottom back right LED
      delay(delayValue);
      break;
      
      case 6:
      lcd.print("corners2()");      
      analogWrite(TFR, brightness);    //turns on the top front right LED
      analogWrite(BRL, brightness);    //turns on the bottom back left LED  
      delay(delayValue);
      break;
      
      case 7:
      lcd.print("all()");
      analogWrite(TFL, brightness);
      analogWrite(TFR, brightness);
      analogWrite(TRL, brightness);
      analogWrite(TRR, brightness);
      analogWrite(BFL, brightness);
      analogWrite(BFR, brightness);
      analogWrite(BRL, brightness);
      analogWrite(BRR, brightness); 
      delay(delayValue);
      break;
      
      case 8:
      lcd.print("chaseTop()");
      for(int l = 0; l < 3; l++){
        //a for loop has been used here to chase more than once
        for(i = 0; i < 4; i++){
          //this for loop turns on each LED in the array chaseTop
          analogWrite(chaseTop[i], brightness);
          delay(100);
          analogWrite(chaseTop[i], 0);
        }
        i = 0;    //return the value of i back to it's original value
      }
      break;
      
      case 9:
      lcd.print("chaseBottom()");
      for(int l = 0; l < 3; l++){
        //a for loop has been used here to chase more than once
        for(i = 0; i < 4; i++){
          //this for loop turns on each LED in the array chaseBottom
          analogWrite(chaseBottom[i], brightness);
          delay(100);
          analogWrite(chaseBottom[i], 0);
        }
        i = 0;    //return the value of i back to it's original value
      }
      break;
      
      case 10:
      lcd.print("chaseLeftSide()");
      for(int l = 0; l < 3; l++){
        //a for loop has been used here to chase more than once
        for(i = 0; i < 4; i++){
          //this for loop turns on each LED in the array chaseLeftSide
          analogWrite(chaseLeftSide[i], brightness);
          delay(100);
          analogWrite(chaseLeftSide[i], 0);
        }
        i = 0;    //return the value of i back to it's original value
      }
      break;
      
      case 11:
      lcd.print("chaseRightSide()");
      for(int l = 0; l < 3; l++){
        //a for loop has been used here to chase more than once
        for(i = 0; i < 4; i++){
          //this for loop turns on each LED in the array chaseRightSide
          analogWrite(chaseRightSide[i], brightness);
          delay(100);
          analogWrite(chaseRightSide[i], 0);
        }
        i = 0;    //return the value of i back to it's original value
      }
      break;
      
      case 12:
      lcd.print("chaseCorners()");
      for(int l = 0; l < 3; l++){
        //a for loop has been used here to chase more than once
        for(i = 0; i < 4; i++){
          //this for loop turns on each LED in the array chaseCorners
          analogWrite(chaseCorners[i], brightness);
          delay(100);
          analogWrite(chaseCorners[i], 0);
        }
        i = 0;    //return the value of i back to it's original value
      }
      break;
      
      case 13:
      lcd.print("chaseCorners1()");
      for(int l = 0; l < 3; l++){
        //a for loop has been used here to chase more than once
        for(i = 0; i < 4; i++){
          //this for loop turns on each LED in the array chaseCorners1
          analogWrite(chaseCorners1[i], brightness);
          delay(100);
          analogWrite(chaseCorners1[i], 0);
        }
        i = 0;    //return the value of i back to it's original value
      }
      break;
  }
 }
}