Arduino Secret Pattern Lock

Introduction

In this project, we are making a pattern lock using Arduino and Solenoid lock. The lock will only get opened when the correct pattern is entered. the pattern is a combination of “long” and “short” press of the pattern switch.

Hardware Used

Components	AliExpress	Banggood	Amazon.com	Amazon.in	Win Source
Micro push-button
Arduino Nano
TIP120 transistor
Resistors 2.3k,10k(kit)
1N4007 Diode
Solenoid Lock

Watch the video

Theory

The code will constantly monitor the enter switch and patter switch state and store it
Whenever I press the pattern button, the time from millis() function will be stored in two variables, one for press time and one for release time.
then the time difference between the release and press will be calculated and stored.
then using an if condition the program will check whether the time difference is less-than or greater-than the predefined time for “short” and “long” press.
then the code will check whether there is any space for the last detected press and if will be stored to the nearly available NULL space in the pattern lock array until all the array is filled
now if we press the enter button the program will compare the default pattern and the patter which you just entered.
if the pattern is true then the transistor will turn on and all the values stored to the pattern array will be erased.
if the pattern is false then the transistor will remain off and all the values stored to the pattern array will be erased.
also, I have added some LEDs for indication

Circuit

Connect the Circuit as shown,

Digital pin 2 and 3 to enter and the pattern button.
Digital pin 5 and 6 for Red and Green LEDs.
Digital pin 12 to the transistor base.
Transistor emitter to GND.
Transistor collector to Solenoid ground.
12v to Solenoid VCC.
Don’t forget to connect ground of 12 to ground of Arduino
The diode in between VCC and ground of solenoid
and don’t forget all the resistors.

Arduino Code

//https://diyusthad.com

#define pSw 2 //pattern switch pin

#define enter 3 //enter switch pin

#define redLED 5 //red led pin

#define greenLED 6 //green led pin

#define lock 12 //transistor pin

int pattern[4] = {NULL, NULL, NULL, NULL};

int pcode[4] = {1, 2, 2, 1}; //Enter your code 1 for short press and 2 for long press

double presstime = 0, releasetime = 0; //for saving press and release time

double timediff; //for storing time diffrence

bool flag1 = 1, flag2 = 0; //flag values

bool enterSwStatus; //for storing enter switch status

bool patternSwStatus; // for storing patern switch status

void setup() {

pinMode(pSw, INPUT);

pinMode(enter, INPUT);

pinMode(redLED, OUTPUT);

pinMode(greenLED, OUTPUT);

pinMode(lock, OUTPUT); digitalWrite(lock, LOW);

Serial.begin(115200);

digitalWrite(redLED, LOW);

delay(100);

digitalWrite(redLED, HIGH);

digitalWrite(greenLED, LOW);

delay(100);

digitalWrite(greenLED, HIGH);

}

void loop() {

if (digitalRead(pSw) == 1 && flag2 == 0)

{

presstime = millis();

flag1 = 0;

flag2 = 1;

delay(10);

}

if (digitalRead(pSw) == 0 && flag1 == 0)

{

releasetime = millis();

flag1 = 1;

delay(10);

timediff = releasetime - presstime;

if (timediff <= 250)

{

Serial.println("short");

digitalWrite(redLED, LOW);

delay(10);

digitalWrite(redLED, HIGH);

flag2 = 0;

flag1 = 1;

while (true)

{

if (pattern[0] == 0)

{

pattern[0] = 1;

break;

}

if (pattern[1] == 0)

{

pattern[1] = 1;

break;

}

if (pattern[2] == 0)

{

pattern[2] = 1;

break;

}

if (pattern[3] == 0)

{

pattern[3] = 1;

break;

}

break;

}

else if (timediff >= 250)

{

Serial.println("long");

digitalWrite(redLED, LOW);

delay(10);

digitalWrite(redLED, HIGH);

flag2 = 0;

flag1 = 1;

while (true)

{

if (pattern[0] == 0)

{

pattern[0] = 2;

break;

}

if (pattern[1] == 0)

{

pattern[1] = 2;

break;

}

if (pattern[2] == 0)

{

pattern[2] = 2;

break;

}

if (pattern[3] == 0)

{

pattern[3] = 2;

break;

}

break;

}

patternSwStatus = 1;

}

if (digitalRead(enter) > 0 && enterSwStatus == 0)

{

enterSwStatus = 1;

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

{

Serial.print(pattern[i]);

}

Serial.println("");

if (unlock() == false)

{

Serial.println("wrong");

digitalWrite(redLED, LOW);

delay(200);

digitalWrite(redLED, HIGH);

}

else

{

Serial.println("access granted");

digitalWrite(greenLED, LOW);

digitalWrite(lock, HIGH);

delay(10000);

digitalWrite(greenLED, HIGH);

digitalWrite(lock, LOW);

}

patternSwStatus = 0;

pattern[0] = NULL;

pattern[1] = NULL;

pattern[2] = NULL;

pattern[3] = NULL;

}

if (digitalRead(enter) == 0)

enterSwStatus = 0;

}

int unlock()

{

if (pcode[0] != pattern [0])

return false;

else if (pcode[1] != pattern [1])

return false;

else if (pcode[2] != pattern [2])

return false;

else if (pcode[3] != pattern [3])

return false;

else

return true;

}

//https://diyusthad.com #define pSw 2 //pattern switch pin #define enter 3 //enter switch pin #define redLED 5 //red led pin #define greenLED 6 //green led pin #define lock 12 //transistor pin int pattern[4] = {NULL, NULL, NULL, NULL}; int pcode[4] = {1, 2, 2, 1}; //Enter your code 1 for short press and 2 for long press double presstime = 0, releasetime = 0; //for saving press and release time double timediff; //for storing time diffrence bool flag1 = 1, flag2 = 0; //flag values bool enterSwStatus; //for storing enter switch status bool patternSwStatus; // for storing patern switch status void setup() { pinMode(pSw, INPUT); pinMode(enter, INPUT); pinMode(redLED, OUTPUT); pinMode(greenLED, OUTPUT); pinMode(lock, OUTPUT); digitalWrite(lock, LOW); Serial.begin(115200); digitalWrite(redLED, LOW); delay(100); digitalWrite(redLED, HIGH); digitalWrite(greenLED, LOW); delay(100); digitalWrite(greenLED, HIGH); } void loop() { if (digitalRead(pSw) == 1 && flag2 == 0) { presstime = millis(); flag1 = 0; flag2 = 1; delay(10); } if (digitalRead(pSw) == 0 && flag1 == 0) { releasetime = millis(); flag1 = 1; delay(10); timediff = releasetime - presstime; if (timediff <= 250) { Serial.println("short"); digitalWrite(redLED, LOW); delay(10); digitalWrite(redLED, HIGH); flag2 = 0; flag1 = 1; while (true) { if (pattern[0] == 0) { pattern[0] = 1; break; } if (pattern[1] == 0) { pattern[1] = 1; break; } if (pattern[2] == 0) { pattern[2] = 1; break; } if (pattern[3] == 0) { pattern[3] = 1; break; } break; } } else if (timediff >= 250) { Serial.println("long"); digitalWrite(redLED, LOW); delay(10); digitalWrite(redLED, HIGH); flag2 = 0; flag1 = 1; while (true) { if (pattern[0] == 0) { pattern[0] = 2; break; } if (pattern[1] == 0) { pattern[1] = 2; break; } if (pattern[2] == 0) { pattern[2] = 2; break; } if (pattern[3] == 0) { pattern[3] = 2; break; } break; } } patternSwStatus = 1; } if (digitalRead(enter) > 0 && enterSwStatus == 0) { enterSwStatus = 1; for (int i = 0; i < 4; i++) { Serial.print(pattern[i]); } Serial.println(""); if (unlock() == false) { Serial.println("wrong"); digitalWrite(redLED, LOW); delay(200); digitalWrite(redLED, HIGH); } else { Serial.println("access granted"); digitalWrite(greenLED, LOW); digitalWrite(lock, HIGH); delay(10000); digitalWrite(greenLED, HIGH); digitalWrite(lock, LOW); } patternSwStatus = 0; pattern[0] = NULL; pattern[1] = NULL; pattern[2] = NULL; pattern[3] = NULL; } if (digitalRead(enter) == 0) enterSwStatus = 0; } int unlock() { if (pcode[0] != pattern [0]) return false; else if (pcode[1] != pattern [1]) return false; else if (pcode[2] != pattern [2]) return false; else if (pcode[3] != pattern [3]) return false; else return true; }

//https://diyusthad.com

#define pSw 2 //pattern switch pin
#define enter 3 //enter switch pin
#define redLED 5 //red led pin
#define greenLED 6 //green led pin
#define lock 12 //transistor pin
int pattern[4] = {NULL, NULL, NULL, NULL};
int pcode[4] = {1, 2, 2, 1}; //Enter your code 1 for short press and 2 for long press
double presstime = 0, releasetime = 0; //for saving press and release time
double timediff; //for storing time diffrence
bool flag1 = 1, flag2 = 0; //flag values 
bool enterSwStatus; //for storing enter switch status 
bool patternSwStatus; // for storing patern switch status 

void setup() {

  pinMode(pSw, INPUT);
  pinMode(enter, INPUT);
  pinMode(redLED, OUTPUT);
  pinMode(greenLED, OUTPUT);
  pinMode(lock, OUTPUT); digitalWrite(lock, LOW);
  Serial.begin(115200);

  digitalWrite(redLED, LOW);
  delay(100);
  digitalWrite(redLED, HIGH);
  digitalWrite(greenLED, LOW);
  delay(100);
  digitalWrite(greenLED, HIGH);

}

void loop() {

  if (digitalRead(pSw) == 1 && flag2 == 0)
  {
    presstime = millis();
    flag1 = 0;
    flag2 = 1;
    delay(10);
  }
  if (digitalRead(pSw) == 0 && flag1 == 0)
  {
    releasetime = millis();
    flag1 = 1;
    delay(10);
    timediff = releasetime - presstime;

    if (timediff <= 250)
    {
      Serial.println("short");
      digitalWrite(redLED, LOW);
      delay(10);
      digitalWrite(redLED, HIGH);
      flag2 = 0;
      flag1 = 1;
      while (true)
      {
        if (pattern[0] == 0)
        {
          pattern[0] = 1;
          break;
        }
        if (pattern[1] == 0)
        {
          pattern[1] = 1;
          break;
        }
        if (pattern[2] == 0)
        {
          pattern[2] = 1;
          break;
        }
        if (pattern[3] == 0)
        {
          pattern[3] = 1;
          break;
        }
        break;
      }

    }
    else if (timediff >= 250)
    {
      Serial.println("long");
      digitalWrite(redLED, LOW);
      delay(10);
      digitalWrite(redLED, HIGH);
      flag2 = 0;
      flag1 = 1;
      while (true)
      {
        if (pattern[0] == 0)
        {
          pattern[0] = 2;
          break;
        }
        if (pattern[1] == 0)
        {
          pattern[1] = 2;
          break;
        }
        if (pattern[2] == 0)
        {
          pattern[2] = 2;
          break;
        }
        if (pattern[3] == 0)
        {
          pattern[3] = 2;
          break;
        }
        break;
      }
    }
    patternSwStatus = 1;
  }


  if (digitalRead(enter) > 0 && enterSwStatus == 0)
  {
    enterSwStatus = 1;
    for (int i = 0; i < 4; i++)
    {
      Serial.print(pattern[i]);
    }
    Serial.println("");
    if (unlock() == false)
    {
      Serial.println("wrong");
      digitalWrite(redLED, LOW);
      delay(200);
      digitalWrite(redLED, HIGH);
    }
    else
    {
      Serial.println("access granted");
      digitalWrite(greenLED, LOW);
      digitalWrite(lock, HIGH);
      delay(10000);
      digitalWrite(greenLED, HIGH);
      digitalWrite(lock, LOW);
    }
    patternSwStatus = 0;
    pattern[0] = NULL;
    pattern[1] = NULL;
    pattern[2] = NULL;
    pattern[3] = NULL;
  }
  if (digitalRead(enter) == 0)
    enterSwStatus = 0;

}
int unlock()
{
  if (pcode[0] != pattern [0])
    return false;
  else if (pcode[1] != pattern [1])
    return false;
  else if (pcode[2] != pattern [2])
    return false;
  else if (pcode[3] != pattern [3])
    return false;
  else
    return true;
}

How to change the LOCK CODE?

int pcode[4] = {1, 2, 2, 1};

Enter your code “1” for short press and “2” for long press in the above-mentioned line.

For example, if you want to set your code as “long short short short” then change the line to this ????????

int pcode[4] = {2, 1, 1, 1};

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Arduino Secret Pattern Lock

Introduction

Hardware Used

Watch the video

Theory

Circuit

Arduino Code

How to change the LOCK CODE?

RFID Solenoid Lock Using Arduino Nano

Using RFID to Lock/Unlock computer

Position control of stepper motor using potentiometers

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Introduction

Hardware Used

Watch the video

Theory

Circuit

Arduino Code

How to change the LOCK CODE?

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RFID Solenoid Lock Using Arduino Nano

Using RFID to Lock/Unlock computer

Position control of stepper motor using potentiometers

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