Published August 22, 2020 © CC BY

Code Lock Concept

Only my 2nd attempt at anything. Connected motor to L239D and a joystick for my 1st go and thought a Code Lock would be interesting to setup

BeginnerShowcase (no instructions)2 hours535

Things used in this project

Hardware components

Breadboard (generic)

Adafruit Standard LCD - 16x2 White on Blue

IR receiver (generic)

Buzzer

Arduino UNO

Rotary Potentiometer, 10 kohm

Resistor 10k ohm

Elegoo RGB LED

Software apps and online services

Arduino IDE

Story

This is the second time I've put anything together, using an Elegoo UNO R3...

I decided to step it up a bit and make something a little more complicated than my first play around, which was just a fan, being driven by a motor, which was controlled by an L293D.

I thought a Code Lock would be interesting to try and setup, although, I have no switches and nothing to actually lock anything, so I decided to use an LCD, LED and a passive buzzer.

LCD for visual feedback with a potentiometer to control contrast.
IR receiver taking input from remote control (would have been a keypad, but need more parts).
Passive buzzer for audio feedback.
RGB LED with 3 10k resistors (mainly just to reduce brightness) for a little more visual feedback.
All controlled with an UNO.

I can input 8 digits, and it gives me 3 attempts to get it correct.

It's pretty basic code-wise in terms of the actual code lock, once 8 characters have been entered it checks that against a hard coded String.

If I fail an attempt, it will sounds an error noise and will flash the LED red, then back to blue.

If I go again after failing all 3 attempts, it will sound an alarm and set the LED to red.

If I put in the right code, it sounds a success noise, displays a new message, and set LED to green.

The standby button on the remote will also turn off/on the voltage to the LCD, LED and passive buzzer and will sound an off/on noise.

It took me a while to get the wiring anywhere near as neat as it is. Though, I don't have enough wires to make it look as neat as it does in the schematic!

The passive buzzer is much smaller than the one in the schematic and the IR receiver is flipped on the actual breadboard to keep wires from blocking it.

Code

Code Lock Code

#include "IRremote.h"
#include "IR.h"
#include "pitches.h"
#include "LiquidCrystal.h"
#define BLUE 6
#define GREEN 9
#define RED 10
#define LCD 13

LiquidCrystal lcd(2, 4, 7, 3, 5, 8);
IRrecv irrecv(RECEIVER);     // create instance of 'irrecv'
decode_results results;      // create instance of 'decode_results'

boolean isPowerButtonPressed = false;
boolean isLedOn = false;
int redValue;
int greenValue;
int blueValue;
int duration = 150;  // 500 miliseconds
int codeDigitCount = 0;
int attemptsRemaining = 3;
String codeInputted = "";

void PlayMelody(const char* type)
{
  int success[] = { NOTE_B5, NOTE_C6, NOTE_B5, NOTE_C6, NOTE_B5, NOTE_C6, NOTE_B5, NOTE_C6 };
  int error[] = { NOTE_C5, NOTE_D5, NOTE_C5, NOTE_D5 };
  int off[] = { NOTE_C6, NOTE_B5, NOTE_A5, NOTE_G5, NOTE_F5, NOTE_E5, NOTE_D5, NOTE_C5 };
  int on[] = { NOTE_C5, NOTE_D5, NOTE_E5, NOTE_F5, NOTE_G5, NOTE_A5, NOTE_B5, NOTE_C6 };
  int alarm[] = { NOTE_A5, NOTE_A4, NOTE_A5, NOTE_A2, NOTE_A5, NOTE_A2, NOTE_A5, NOTE_A4,NOTE_A5, NOTE_A4, NOTE_A5, NOTE_A2, NOTE_A5, NOTE_A2, NOTE_A5, NOTE_A4,};
  if (type == "success") {
    for (int thisNote = 0; thisNote < 8; thisNote++) {
      tone(12, success[thisNote], duration);
      delay(100);
    }
  } else if (type == "error") {
    for (int thisNote = 0; thisNote < 4; thisNote++) {
      tone(12, error[thisNote], duration);
      delay(100);
    }
  } else if (type == "off") {
    for (int thisNote = 0; thisNote < 8; thisNote++) {
      tone(12, off[thisNote], duration);
      delay(100);
    }
  } else if (type == "on") {
    for (int thisNote = 0; thisNote < 8; thisNote++) {
      tone(12, on[thisNote], duration);
      delay(100);
    }
  } else if (type == "alarm") {
    for (int thisNote = 0; thisNote < 16; thisNote++) {
      tone(12, alarm[thisNote], 500);
      delay(500);
    }
  }
}

void PowerOff()
{
  redValue = 0;
  greenValue = 0;
  blueValue = 0;
  codeDigitCount = 0;
  codeInputted = "";
  isPowerButtonPressed = false;
  SetLedColour(redValue, greenValue, blueValue);
  PlayMelody("off");
  attemptsRemaining = 3;
  ClearLcdScreen();
  digitalWrite(LCD, LOW);
}

void PowerOn()
{
  redValue = 0;
  greenValue = 0;
  blueValue = 255;
  codeDigitCount = 0;
  codeInputted = "";
  isPowerButtonPressed = false;
  SetLedColour(redValue, greenValue, blueValue);
  PlayMelody("on");
  ClearLcdScreen();
  ResetLcdScreen();
  digitalWrite(LCD, HIGH);
}

void TooManyIncorrectAttempts()
{
  redValue = 255;
  greenValue = 0;
  blueValue = 0;
  SetLedColour(redValue, greenValue, blueValue);
  lcd.setCursor(0, 0);
  ClearLcdScreen();
  lcd.setCursor(0, 0);
  lcd.print("Too bad...");
  lcd.setCursor(0, 1);
  lcd.print("Alarm Triggered!!!");
  PlayMelody("alarm");
}

void MarqueeScroll() {
  for (int positionCounter = 7; positionCounter > 0; positionCounter--) {
    lcd.scrollDisplayLeft();
    delay(250);
  }
  delay(250);
  for (int positionCounter = 7; positionCounter > 0; positionCounter--) {
    lcd.scrollDisplayRight();
    delay(250);
  }
  delay(250);
  for (int positionCounter = 7; positionCounter > 0; positionCounter--) {
    lcd.scrollDisplayRight();
    delay(250);
  }
  delay(250);
  for (int positionCounter = 7; positionCounter > 0; positionCounter--) {
    lcd.scrollDisplayLeft();
    delay(250);
  }
  delay(250);
}

void TextMarquee() {
  MarqueeScroll();
  
  ClearLcdScreen();
  lcd.setCursor(6, 1);
  lcd.print(".42.");
  lcd.setCursor(0, 0);
  delay(1000);
  
  ClearLcdScreen();
  lcd.setCursor(6, 0);
  lcd.print(".42.");
  
  ClearLcdScreen();
  lcd.setCursor(6, 1);
  lcd.print(".42.");
  
  ClearLcdScreen();
  lcd.setCursor(6, 0);
  lcd.print(".42.");
}

void CodeAccepted()
{
  redValue = 0;
  greenValue = 255;
  blueValue = 0;
  SetLedColour(redValue, greenValue, blueValue);
  lcd.setCursor(0, 0);
  lcd.print("Code Accepted!!!");
  PlayMelody("success");
  delay(2000);

  ClearLcdScreen();
  lcd.setCursor(0, 0);
  lcd.print("The answer to");
  lcd.setCursor(0, 1);
  lcd.print("the ultimate ");
  delay(2000);

  ClearLcdScreen();
  lcd.setCursor(0, 0);
  lcd.print("question of life,");
  lcd.setCursor(0, 1);
  lcd.print("the universe");
  delay(2000);

  ClearLcdScreen();
  lcd.setCursor(0, 0);
  lcd.print("and everything");
  lcd.setCursor(0, 1);
  lcd.print("is...");
  delay(2500);

  ClearLcdScreen();
  lcd.setCursor(6, 0);
  lcd.print(".42.");
  lcd.setCursor(0, 0);
  delay(1000);

  TextMarquee();

}

void IncorrectCode()
{
  attemptsRemaining = attemptsRemaining - 1;
  redValue = 255;
  greenValue = 0;
  blueValue = 0;
  SetLedColour(redValue, greenValue, blueValue);

  lcd.setCursor(0, 0);
  lcd.print("Incorrect code!");
  lcd.setCursor(0, 1);
  String message = (String(attemptsRemaining) + "/3 attempts.");
  lcd.print(message);
  PlayMelody("error");
  delay(2000);


  redValue = 0;
  blueValue = 255;
  SetLedColour(redValue, greenValue, blueValue);
  ClearLcdScreen();
  ResetLcdScreen();
}

void SetupRgbLed()
{
  pinMode(RED, OUTPUT);
  pinMode(GREEN, OUTPUT);
  pinMode(BLUE, OUTPUT);
  digitalWrite(RED, LOW);
  digitalWrite(GREEN, LOW);
  digitalWrite(BLUE, HIGH);
  PlayMelody("on");
}

void SetupIrReceiever()
{
  Serial.begin(9600);
  Serial.println("IR Receiver Button Decode");
  irrecv.enableIRIn();
}

void SetLedColour(int redValue, int greenValue, int blueValue)
{
  analogWrite(RED, redValue);
  analogWrite(GREEN, greenValue);
  analogWrite(BLUE, blueValue);
}

void  SetupLcdDisplay()
{
  pinMode(LCD, OUTPUT);
  digitalWrite(LCD, HIGH);
  lcd.begin(16, 2);
  lcd.print("Please enter");
  lcd.setCursor(0, 1);
  lcd.print("unlock code...");
}

void ClearLcdScreen()
{
  lcd.setCursor(0, 0);
  lcd.print("                                ");
  lcd.setCursor(0, 1);
  lcd.print("                                ");
}

void ResetLcdScreen()
{
  lcd.setCursor(0, 0);
  lcd.print("Please enter");
  lcd.setCursor(0, 1);
  lcd.print("unlock code...");
}

void LoopIrReceiever()
{
  int tmpValue;
  if (irrecv.decode(&results))
  {
    for (int i = 0; i < 23; i++)
    {
      if ((keyValue[i] == results.value) && (i < KEY_NUM))
      {
        ClearLcdScreen();
        switch (results.value)
        {
          case 0xFFA25D:
            Serial.println("POWER");
            isPowerButtonPressed = true;
            isLedOn = !isLedOn;
            break;
            
          case 0xFFE21D: Serial.println("FUNC/STOP"); break;
          case 0xFF629D: Serial.println("VOL+"); break;
          case 0xFF22DD: Serial.println("FAST BACK");    break;
          case 0xFF02FD: Serial.println("PAUSE");    break;
          case 0xFFC23D: Serial.println("FAST FORWARD");   break;
          case 0xFFE01F: Serial.println("DOWN");    break;
          case 0xFFA857: Serial.println("VOL-");    break;
          case 0xFF906F: Serial.println("UP");    break;
          case 0xFF9867: Serial.println("EQ");    break;
          case 0xFFB04F: Serial.println("ST/REPT");    break;

          case 0xFF6897:
            codeInputted = codeInputted + "0";
            break;

          case 0xFF30CF:
            codeInputted = codeInputted + "1";
            break;

          case 0xFF18E7:
            codeInputted = codeInputted + "2";
            break;

          case 0xFF7A85:
            codeInputted = codeInputted + "3";
            break;

          case 0xFF10EF:
            codeInputted = codeInputted + "4";
            break;

          case 0xFF38C7:
            codeInputted = codeInputted + "5";
            break;

          case 0xFF5AA5:
            codeInputted = codeInputted + "6";
            break;

          case 0xFF42BD:
            codeInputted = codeInputted + "7";
            break;

          case 0xFF4AB5:
            codeInputted = codeInputted + "8";
            break;

          case 0xFF52AD:
            codeInputted = codeInputted + "9";
            break;

          case 0xFFFFFFFF:
            Serial.println(" REPEAT");
            break;

          default:
            Serial.println("other button");
            break;
        }


        Serial.println("codeInputted");
        Serial.println(codeInputted);
        Serial.println("codeDigitCount");
        Serial.println(codeDigitCount);


        if (isPowerButtonPressed && isLedOn) {
          PowerOff();
        } else if (isPowerButtonPressed && !isLedOn) {
          PowerOn();
        } else {
          if (!attemptsRemaining) {
            TooManyIncorrectAttempts();
          } else {
            if (codeDigitCount >= 7) {
              if (codeInputted == "01020304") {
                CodeAccepted();
              } else {
                IncorrectCode();
              }
              codeDigitCount = 0;
              codeInputted = "";
            } else {
              codeDigitCount = codeDigitCount + 1;
              switch (codeDigitCount) {
                case 1:
                  ClearLcdScreen();
                  lcd.setCursor(0, 0);
                  lcd.print("*");
                  break;
                case 2:
                  ClearLcdScreen();
                  lcd.setCursor(0, 0);
                  lcd.print("**");
                  break;
                case 3:
                  ClearLcdScreen();
                  lcd.setCursor(0, 0);
                  lcd.print("***");
                  break;
                case 4:
                  ClearLcdScreen();
                  lcd.setCursor(0, 0);
                  lcd.print("****");
                  break;
                case 5:
                  ClearLcdScreen();
                  lcd.setCursor(0, 0);
                  lcd.print("*****");
                  break;
                case 6:
                  ClearLcdScreen();
                  lcd.setCursor(0, 0);
                  lcd.print("******");
                  break;
                case 7:
                  ClearLcdScreen();
                  lcd.setCursor(0, 0);
                  lcd.print("*******");
                  break;
                case 8:
                  ClearLcdScreen();
                  lcd.setCursor(0, 0);
                  lcd.print("********");
                  break;
              }
            }
          }
        }
      }
      else if (REPEAT == i)
      {
        results.value = tmpValue;
      }
    }
    irrecv.resume();
  }
}

void setup()
{
  SetupRgbLed();
  SetupIrReceiever();
  SetupLcdDisplay();
}

void loop()
{
  LoopIrReceiever();
}

Credits

Dammeul

1 project • 1 follower

Developer by trade. Over 15 years Dev and Infrastructure experience. Complete beginner to Micro-controllers though. Bare with me..!

Code Lock Concept

Things used in this project

Hardware components

Software apps and online services

Story

Schematics

Schematic Image

Fritizing File

Code

Code Lock Code

Credits

Dammeul

Comments

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Code Lock Concept

Code Lock Concept

Things used in this project

Hardware components

Software apps and online services

Story

Schematics

Schematic Image

Fritizing File

Code

Code Lock Code

Credits

Dammeul

Comments

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