My LCD screen is overwriting white blocks [wrong wiring]

Other Hardware Displays
1

When i print this code my lcd screen starts filling my screens with white block i tried a for loop etc and adding a delay but it did not change the result. i tried a different simpler code and my screen worked fine i don't get it? can anybody help me? I am using a 4x4 Keypad, arduino uno, motionsensor, buzzer and a lcd screen.

code_1:

/*
  Arduino Security and Alarm System

  by Dejan Nedelkovski,
  www.HowToMechatronics.com

*/

#include <LiquidCrystal.h> // includes the LiquidCrystal Library 
#include <Keypad.h>

#define buzzer 8
#define trigPin 9
#define echoPin 10

long duration;
int distance, initialDistance, currentDistance, i;
int screenOffMsg = 0;
int Contrast = 50;
String password = "1234";
String tempPassword;
boolean activated = false; // State of the alarm
boolean isActivated;
boolean activateAlarm = false;
boolean alarmActivated = false;
boolean enteredPassword; // State of the entered password to stop the alarm
boolean passChangeMode = false;
boolean passChanged = false;


const byte ROWS = 4; //four rows
const byte COLS = 4; //four columns
char keypressed;
//define the cymbols on the buttons of the keypads
char keyMap[ROWS][COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};
byte rowPins[ROWS] = {7, 6, 5, 4}; //Rows
byte colPins[COLS] = {3, 2, 12, 11}; //Columns

Keypad myKeypad = Keypad( makeKeymap(keyMap), rowPins, colPins, ROWS, COLS);
LiquidCrystal lcd(2, 3, 4, 5, 6, 7);

void setup() {
  analogWrite(13, Contrast);
  lcd.begin(16, 2);
  pinMode(buzzer, OUTPUT); // Set buzzer as an output
  pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
  pinMode(echoPin, INPUT); // Sets the echoPin as an Input
  Serial.begin(9600);
}

void loop() {
  if (activateAlarm) {
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Alarm will be");
    lcd.setCursor(0, 1);
    lcd.print("activated in");

    int countdown = 9; // 9 seconds count down before activating the alarm
    while (countdown != 0) {
      lcd.setCursor(13, 1);
      lcd.print(countdown);
      countdown--;
      tone(buzzer, 700, 100);
      delay(1000);
    }
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Alarm Activated!");
    initialDistance = getDistance();
    activateAlarm = fallse;
    alarmActivated = true;
  }

  if (alarmActivated == true) {
    currentDistance = getDistance() + 10;
    if ( currentDistance < initialDistance) {
      tone(buzzer, 1000); // Send 1KHz sound signal
      lcd.clear();
      enterPassword();
    }
  }

  if (!alarmActivated) {
    if (screenOffMsg == 0 ) {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("A - Activate");
      lcd.setCursor(0, 1);
      lcd.print("B - Change Pass");
      screenOffMsg = 1;
    }
    for (int i = 0; i < 11; i++) {
      keypressed = myKeypad.getKey();
      Serial.println(keypressed);
    }

    if (keypressed == 'A') {      //If A is pressed, activate the alarm
      tone(buzzer, 1000, 200);
      activateAlarm = true;
    }
    else if (keypressed == 'B') {
      lcd.clear();
      int i = 1;
      tone(buzzer, 2000, 100);
      tempPassword = "";
      lcd.setCursor(0, 0);
      lcd.print("Current Password");
      lcd.setCursor(0, 1);
      lcd.print(">");
      passChangeMode = true;
      passChanged = true;
      while (passChanged) {
        keypressed = myKeypad.getKey();
        if (keypressed != NO_KEY) {
          if (keypressed == '0' || keypressed == '1' || keypressed == '2' || keypressed == '3' ||
              keypressed == '4' || keypressed == '5' || keypressed == '6' || keypressed == '7' ||
              keypressed == '8' || keypressed == '9' ) {
            tempPassword += keypressed;
            lcd.setCursor(i, 1);
            lcd.print("*");
            i++;
            tone(buzzer, 2000, 100);
          }
        }
        if (i > 5 || keypressed == '#') {
          tempPassword = "";
          i = 1;
          lcd.clear();
          lcd.setCursor(0, 0);
          lcd.print("Current Password");
          lcd.setCursor(0, 1);
          lcd.print(">");
        }
        if ( keypressed == '*') {
          i = 1;
          tone(buzzer, 2000, 100);
          if (password == tempPassword) {
            tempPassword = "";
            lcd.clear();
            lcd.setCursor(0, 0);
            lcd.print("Set New Password");
            lcd.setCursor(0, 1);
            lcd.print(">");
            while (passChangeMode) {
              keypressed = myKeypad.getKey();
              if (keypressed != NO_KEY) {
                if (keypressed == '0' || keypressed == '1' || keypressed == '2' || keypressed == '3' ||
                    keypressed == '4' || keypressed == '5' || keypressed == '6' || keypressed == '7' ||
                    keypressed == '8' || keypressed == '9' ) {
                  tempPassword += keypressed;
                  lcd.setCursor(i, 1);
                  lcd.print("*");
                  i++;
                  tone(buzzer, 2000, 100);
                }
              }
              if (i > 5 || keypressed == '#') {
                tempPassword = "";
                i = 1;
                tone(buzzer, 2000, 100);
                lcd.clear();
                lcd.setCursor(0, 0);
                lcd.print("Set New Password");
                lcd.setCursor(0, 1);
                lcd.print(">");
              }
              if ( keypressed == '*') {
                i = 1;
                tone(buzzer, 2000, 100);
                password = tempPassword;
                passChangeMode = false;
                passChanged = false;
                screenOffMsg = 0;
              }
            }
          }
        }
      }
    }
  }
}

void enterPassword() {
  int k = 5;
  tempPassword = "";
  activated = true;
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print(" *** ALARM *** ");
  lcd.setCursor(0, 1);
  lcd.print("Pass>");
  while (activated) {
    keypressed = myKeypad.getKey();
    if (keypressed != NO_KEY) {
      if (keypressed == '0' || keypressed == '1' || keypressed == '2' || keypressed == '3' ||
          keypressed == '4' || keypressed == '5' || keypressed == '6' || keypressed == '7' ||
          keypressed == '8' || keypressed == '9' ) {
        tempPassword += keypressed;
        lcd.setCursor(k, 1);
        lcd.print("*");
        k++;
      }
    }
    if (k > 9 || keypressed == '#') {
      tempPassword = "";
      k = 5;
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print(" *** ALARM *** ");
      lcd.setCursor(0, 1);
      lcd.print("Pass>");
    }
    if ( keypressed == '*') {
      if ( tempPassword == password ) {
        activated = false;
        alarmActivated = false;
        noTone(buzzer);
        screenOffMsg = 0;
      }
      else if (tempPassword != password) {
        lcd.setCursor(0, 1);
        lcd.print("Wrong! Try Again");
        delay(2000);
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print(" *** ALARM *** ");
        lcd.setCursor(0, 1);
        lcd.print("Pass>");
      }
    }
  }
}
// Custom function for the Ultrasonic sensor
long getDistance() {
  //int i=10;

  //while( i<=10 ) {
  // Clears the trigPin
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);

  // Sets the trigPin on HIGH state for 10 micro seconds
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Reads the echoPin, returns the sound wave travel time in microseconds
  duration = pulseIn(echoPin, HIGH);

  // Calculating the distance
  distance = duration * 0.034 / 2;
  //sumDistance += distance;
  //}
  //int averageDistance= sumDistance/10;
  return distance;

}

code_2:

#include <LiquidCrystal.h>
int Contrast = 75;
LiquidCrystal lcd(2, 3, 4, 5, 6, 7);

void setup()
{
  analogWrite(13, Contrast);
  lcd.begin(16, 2);
}
void loop()
{

  lcd.setCursor(0, 0);
  lcd.print("HELLO WORLD!");

  lcd.setCursor(0, 1);
  lcd.print("SUBSCRIBE :]");
  delay(500);
  lcd.clear();

  delay(500);

  /*lcd.scrollDisplayLeft();
    delay(400); */

}
2

You will get help faster if you follow the recommendations on the how to get the best from the forum post.

Format your code.

Post code in a code block.

3

were is it?

4

At the top of every forim section.

5

Welcome to the forum

Please follow the advice given in the link below when posting code, in particular the section entitled 'Posting code and common code problems'

Use code tags (the < CODE/ > icon above the compose window) to make it easier to read and copy for examination

https://forum.arduino.cc/t/how-to-get-the-best-out-of-this-forum

In my experience this is the easiest way to tidy up the code and add the code tags

Start by tidying up your code by using Tools/Auto Format in the IDE to make it easier to read. Then use Edit/Copy for Forum and paste what was copied in a new reply. Code tags will have been added to the code to make it easy to read in the forum thus making it easier to provide help.

6

Welcome to forum.
Redo your post putting code inside tags, by clicking " < code > " at tools bar.

7

activateAlarm = fallse; wrong
activateAlarm = false; correct

The LCD and Keypad use same pins. This is a problem.

Try use analog pins for LCD (A0 = 14..... and so .....)

8

I would just use A0 etc. The problem with the numbers is that it's not portable; e.g. the numbers are different on a Arduino Leonardo or Mega (compared to the Uno).

1 Like
10

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