The code works in simulator but in my real arduino uno the code is succeeding to compile but the LCD is not displaying anything and it just stay light

[luaplemoj_444]

The code works in simulator but in my real arduino uno the code is succeeding to compile but the LCD is not displaying anything and it just stay in light I already installed the right library in the simulatir through my uno

this is my work in simulation

KEYPAD LCD BUZZER SIM Copy (2) - Wokwi ESP32, STM32, Arduino Simulator

this is the code:

#include <Keypad.h>
#include <EEPROM.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
#include <Buzzer.h> // Include the Tone library for buzzer

// Define constants for better readability and maintainability
const int PASSWORD_LENGTH = 5;
const int BUZZER_PIN = 10; // Define the buzzer pin
const int BUZZER_FREQUENCY = 1500; // Define the buzzer frequency
const int MAX_WRONG_ATTEMPTS = 5; // Maximum allowed wrong attempts before locking
const int LOCK_DURATION = 30000; // Lock duration in milliseconds (30 seconds)

// Initialize LCD object
LiquidCrystal_I2C lcd(0x27, 16, 2);

// Declare variables
char password[PASSWORD_LENGTH];
char initial_password[PASSWORD_LENGTH], new_password[PASSWORD_LENGTH];
int vcc = 11;
int i = 0;
int relay_pin = 11;
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] = {2, 3, 4, 5};
byte column_pins[columns] = {6, 7, 8, 9};
Keypad keypad_key = Keypad(makeKeymap(hexaKeys), row_pins, column_pins, rows, columns);
int wrong_attempts = 0; // Counter for wrong attempts
unsigned long lock_start_time = 0; // Timestamp to track lock start time
bool device_locked = false; // Flag to indicate device lock state

// Function prototypes
void setPassword();
void initialpassword();
void buzzOnce();
void buzzEscapeAlarm();
void change();

// Setup function
void setup()
{
    // Initialize LCD
    lcd.begin(16, 2);
    lcd.backlight();

    // Set pin modes
    pinMode(relay_pin, OUTPUT);
    pinMode(vcc, OUTPUT);
    pinMode(BUZZER_PIN, OUTPUT); // Set buzzer pin as output

    // Display startup message
    lcd.print("    WELCOME");
    lcd.setCursor(0, 1); 
    delay(3000);
    lcd.clear();

    // Check if the password is already initialized in EEPROM
    bool password_initialized = true;
    for (int j = 0; j < PASSWORD_LENGTH; j++)
    {
        if (EEPROM.read(j) != j + 49)
        {
            password_initialized = false;
            break;
        }
    }

    if (!password_initialized)
    {
        lcd.print("Set up Password");
        lcd.setCursor(0, 1);
        setPassword();
    }
    else
    {
        // Prompt user to enter password
        lcd.print("Enter Password:");
        lcd.setCursor(0, 1);
        initialpassword();
    }
}

// Main loop function
void loop()
{
    digitalWrite(relay_pin, HIGH);

    // Check if '#' key is pressed to initiate password change
    key_pressed = keypad_key.getKey();
    if (key_pressed == '#' && !device_locked)
        change();

    // Check for keypad input
    if (key_pressed && !device_locked)
    {
        // Mask the password input with '*'
        password[i++] = key_pressed;
        lcd.print('*');
    }

    // Check if password length is reached and device not locked
    if (i == PASSWORD_LENGTH && !device_locked)
    {
        delay(200);

        // Read initial password from EEPROM
        for (int j = 0; j < PASSWORD_LENGTH; j++)
            initial_password[j] = EEPROM.read(j);

        // Check if entered password matches initial password
        if (!(strncmp(password, initial_password, PASSWORD_LENGTH)))
        {
            lcd.clear();
            lcd.print("Pass Accepted");
            digitalWrite(relay_pin, LOW);
            buzzOnce(); // Buzz once for correct password
            delay(2000);
            lcd.setCursor(0, 0);

            lcd.clear();
            lcd.print("Enter Password:");
            lcd.setCursor(0, 1);
            i = 0;
            wrong_attempts = 0; // Reset wrong attempts counter
        }
        else
        {
            // Increment wrong attempts counter
            wrong_attempts++;

            // Check if maximum wrong attempts reached
            if (wrong_attempts >= MAX_WRONG_ATTEMPTS)
            {
                device_locked = true;
                lock_start_time = millis(); // Record lock start time
            }

            digitalWrite(relay_pin, HIGH);
            lcd.clear();
            lcd.print("Wrong Password");
            buzzEscapeAlarm(); // Buzz like an escape alarm for wrong password
            lcd.setCursor(0, 0);

            lcd.clear();
            lcd.print("Enter Password:");
            lcd.setCursor(0, 1);
            i = 0;
        }
    }

    // Check if device is locked
    if (device_locked)
    {
        // Check if lock duration has passed
        if (millis() - lock_start_time >= LOCK_DURATION)
        {
            device_locked = false; // Unlock the device
            lcd.clear();
            lcd.print("Device Unlocked");
            delay(2000);
            lcd.clear();
            lcd.print("Enter Password:");
            lcd.setCursor(0, 1);
        }
        else
        {
            lcd.clear();
            lcd.print("Device in Lock");
            lcd.setCursor(0, 1);
            lcd.print("Wait for 30 secs");
            delay(500);
        }
    }
}

// Function to change password
void change()
{
    int j = 0;
    lcd.clear();
    lcd.print("Current Password");
    lcd.setCursor(0, 1);
    while (j < PASSWORD_LENGTH)
    {
        char key = keypad_key.getKey();
        if (key)
        {
            new_password[j++] = key;
            lcd.print('*'); // Mask the password input with '*'
        }
        key = 0;
    }
    delay(500);

    // Check if entered current password matches initial password
    if ((strncmp(new_password, initial_password, PASSWORD_LENGTH)))
    {
        lcd.clear();
        lcd.print("Wrong Password");
        lcd.setCursor(0, 1);
        lcd.print("Try Again");
        delay(1000);
    }
    else
    {
        j = 0;
        lcd.clear();
        lcd.print("New Password:");
        lcd.setCursor(0, 1);

        while (j < PASSWORD_LENGTH)
        {
            char key = keypad_key.getKey();
            if (key)
            {
                initial_password[j] = key;
                lcd.print('*'); // Mask the password input with '*'
                EEPROM.write(j, key);
                j++;
            }
        }
        lcd.print("Pass Changed");
        delay(1000);
    }

    lcd.clear();
    lcd.print("Enter Password:");
    lcd.setCursor(0, 1);
    key_pressed = 0;
}

// Function to initialize password from EEPROM
void initialpassword()
{
    for (int j = 0; j < PASSWORD_LENGTH; j++)
        EEPROM.write(j, j + 49);
    for (int j = 0; j < PASSWORD_LENGTH; j++)
        initial_password[j] = EEPROM.read(j);
}

// Function to make the buzzer sound once
void buzzOnce()
{
    tone(BUZZER_PIN, 1000, 100); // Buzz at 1000 Hz for 100 ms
}

// Function to make the buzzer sound like an escape alarm
void buzzEscapeAlarm()
{
    for (int i = 0; i < 5; i++)
    {
        tone(BUZZER_PIN, BUZZER_FREQUENCY, 200); // Buzz at specified frequency for 200 ms
        delay(300); // Wait for 300 ms between each buzz
    }
}

// Function to set up a new password
void setPassword()
{
    int j = 0;
    lcd.clear();
    lcd.print("Set Password:");
    lcd.setCursor(0, 1);

    while (j < PASSWORD_LENGTH)
    {
        char key = keypad_key.getKey();
        if (key)
        {
            initial_password[j] = key;
            lcd.print('*'); // Mask the password input with '*'
            EEPROM.write(j, key);
            j++;
        }
    }
    lcd.print("Pass Set");
    delay(1000);
    lcd.clear();
    lcd.print("Enter Password:");
    lcd.setCursor(0, 1);
}

Plss help me in my uno after i compile its all working but the lcd stays in light

[DaveX]

Then it sounds like a wiring/power/hardware problem.

How to get the best out of this forum

Welcome to the Arduino forum! A guide explaining how to get the best out of this forum is available at the link below. Please read it:

[floresta]

Try just the 'Hello World' program on your real hardware and let us know if it works.

Don

[luaplemoj_444]

Yes the lcd work fine and display text in this code
I dont know if theres a problem in the code and this use another library to my lcdI2c

#include <LiquidCrystal_I2C.h>
#include <Keypad.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);
const byte number_of_rows = 4;
const byte number_of_columns = 4;

char row_pins[number_of_rows] = {2, 3, 4, 5};
char column_pins[number_of_columns] = {6, 7, 8, 9};

char key_array[number_of_rows][number_of_columns] = {  
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};

const char *correct_password = "1234"; // Change this to your desired password
char entered_password[5] = ""; // Including space for null terminator

Keypad k = Keypad(makeKeymap(key_array), row_pins, column_pins, number_of_rows, number_of_columns);

const int solenoid_pin = 10; // Connect the solenoid to pin 11

void setup() {
  Serial.begin(9600);
  lcd.init();
  lcd.backlight();
  lcd.setBacklight(HIGH);
  pinMode(solenoid_pin, OUTPUT);
  lcd.print("Enter password:");
  lcd.setCursor(0, 1); // Set cursor to the second row
}

void loop() {
  char key_pressed = k.getKey();
  if (key_pressed) {
    if (strlen(entered_password) < 4) {
      entered_password[strlen(entered_password)] = key_pressed;
      lcd.print("*");
    } else {
      // Entered password length is 4, so clear the display and validate the password
      lcd.clear();
      lcd.print("Enter password:");
      lcd.setCursor(0, 1); // Set cursor to the second row
      if (strcmp(entered_password, correct_password) == 0) {
        lcd.print("Correct Password");
        digitalWrite(solenoid_pin, LOW); // Unlock the solenoid
        delay(2000); // Keep the solenoid unlocked for 2 seconds
        digitalWrite(solenoid_pin, HIGH); // Lock the solenoid
      } else {
        lcd.print("Wrong Password");
      }
      // Reset entered_password for next entry
      memset(entered_password, 0, sizeof(entered_password));
      delay(2000); // Display message for 2 seconds before clearing
      lcd.clear();
      lcd.print("Enter password:");
      lcd.setCursor(0, 1); // Set cursor to the second row
    }
  }
}