Trouble with Electric Door Lock Project

Projects General Guidance
1

Hi there! I am working on an electric door lock system and my LCD won't display the text. I've tried using 2 other LCDs, rewiring, and testing out another code.

IMG_5046
IMG_50461920×2560 399 KB

This is a picture of the wiring, the blue and black wires are not connected right now but they are supposed to connect to a solenoid.

This is the code:

#include <Keypad.h>

#include<LiquidCrystal.h>

#include<EEPROM.h>

LiquidCrystal liquid_crystal_display(9,8,7,6,5,4,);

char password[4];

char initial_password[4],new_password[4];

int i=0;

int relay_pin = 10;

char key_pressed=0;

const byte rows = 4; 

const byte columns = 4; 

char hexaKeys[rows][columns] = {

{'1','2','3','A'},

{'4','5','6','B'},

{'7','8','9','C'},

{'*','0','#','D'}

};

byte row_pins[rows] = {A0,A1,A2,A3};

byte column_pins[columns] = {A4,A5,3,2};   

Keypad keypad_key = Keypad( makeKeymap(hexaKeys), row_pins, column_pins, rows, columns);




void setup()

{

  pinMode(relay_pin, OUTPUT);

  liquid_crystal_display.begin(16,2);

  liquid_crystal_display.print(" DIYhacking.com");

  liquid_crystal_display.setCursor(0,1);

  liquid_crystal_display.print("Electronic Lock ");

  delay(2000);

  liquid_crystal_display.clear();

  liquid_crystal_display.print("Enter Password");

  liquid_crystal_display.setCursor(0,1);

  initialpassword();

}




void loop()

{

  digitalWrite(relay_pin, HIGH);

  key_pressed = keypad_key.getKey();

  if(key_pressed=='#')

    change();

  if (key_pressed)

  {

    password[i++]=key_pressed;

    liquid_crystal_display.print(key_pressed);

      }

  if(i==4)

  {

    delay(200);

    for(int j=0;j<4;j++)

      initial_password[j]=EEPROM.read(j);

    if(!(strncmp(password, initial_password,4)))

    {

      liquid_crystal_display.clear();

      liquid_crystal_display.print("Pass Accepted");

      digitalWrite(relay_pin, LOW);

      delay(2000);

      liquid_crystal_display.setCursor(0,1);

      liquid_crystal_display.print("Pres # to change");

      delay(2000);

      liquid_crystal_display.clear();

      liquid_crystal_display.print("Enter Password:");

      liquid_crystal_display.setCursor(0,1);

      i=0;




    }

    else

    {

      digitalWrite(relay_pin, HIGH);




      liquid_crystal_display.clear();

      liquid_crystal_display.print("Wrong Password");

      liquid_crystal_display.setCursor(0,1);

      liquid_crystal_display.print("Pres # to Change");

      delay(2000);

      liquid_crystal_display.clear();

      liquid_crystal_display.print("Enter Password");

      liquid_crystal_display.setCursor(0,1);

      i=0;




    }

  }

}

void change()

{

  int j=0;

  liquid_crystal_display.clear();

  liquid_crystal_display.print("Current Password");

  liquid_crystal_display.setCursor(0,1);

  while(j<4)

  {

    char key=keypad_key.getKey();

    if(key)

    {

      new_password[j++]=key;

      liquid_crystal_display.print(key);

       

    }

    key=0;

  }

  delay(500);




  if((strncmp(new_password, initial_password, 4)))

  {

    liquid_crystal_display.clear();

    liquid_crystal_display.print("Wrong Password");

    liquid_crystal_display.setCursor(0,1);

    liquid_crystal_display.print("Try Again");

    delay(1000);

  }

  else

  {

    j=0;

    liquid_crystal_display.clear();

    liquid_crystal_display.print("New Password:");

    liquid_crystal_display.setCursor(0,1);

    while(j<4)

    {

      char key=keypad_key.getKey();

      if(key)

      {

        initial_password[j]=key;

        liquid_crystal_display.print(key);

        EEPROM.write(j,key);

        j++;

     

      }

    }

    liquid_crystal_display.print("Pass Changed");

    delay(1000);

  }

  liquid_crystal_display.clear();

  liquid_crystal_display.print("Enter Password");

  liquid_crystal_display.setCursor(0,1);

  key_pressed=0;

}




void initialpassword(){

  for(int j=0;j<4;j++)

    EEPROM.write(j, j+49);

  for(int j=0;j<4;j++)

    initial_password[j]=EEPROM.read(j);

}
2

upload a schematic showing the wiring
how are you powering the devices?

3

Neither blue wire nor black wire is connected.

4

Why

All

The

Spaces

Between

Each

Line

Of

Code?

5

space

for

comments

in

the

future

6

Hi,
Your code does not compile because there is an error on the line:
LiquidCrystal liquid_crystal_display(9,8,7,6,5,4,);
the comma after the 4 is wrong. need to remove it.

I tested your code in the simulator with the comma removed and
the message appeared on the LCD: Enter Password
In your assembly, nothing appears on the LCD?

7

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