An automated garage door that can be locked with a keypad

Projects Programming
1

Im very newbie with this and coding, i dont know a lot of stuff.
So, i want to make a garage with an automated door, that can also be locked and unlocked with a keypad, for a RC car for a school proyect.

The thing is simple, the car goes close to the garage, and if the garage is unlocked, a sensor detects the car, the garage door opens with a servo when the car gets detected.

But when the garage is locked, the garage door doesn't open when getting the car close.

I wanted to make to the door gets locked when pressing '1' in the keypad, then unlocking it pressing '2', and i managed to make it stay lock, but cant unlock it, and i dont know how to solve it. I already tried many ways and looked up some tutorials, but i couldn't find anything that i could understand, is there a way to make a proper lock? I'm somewhat desperate.

PS. The LCD shows the state of the lock.
(also sorry if my english is confusing)

#include <LiquidCrystal.h>
  const int pecho = 13;
  const int ptrig = 12;
  int duration, distance;
  LiquidCrystal lcd(8,7,5,4,3,2);

#include <Servo.h>
  Servo servoMotor;

#include <Keypad.h>
  
  const byte ROWS = 2;
  const byte COLS = 2;

  char Keys[ROWS][COLS] = {      //only using 4 keys from a 4x4 keypad.
  {'1', '2'},
  {'4', '5'},
  };

  byte rowPins[ROWS] = {16, 17};
  byte colPins[COLS] = {14, 15};

  Keypad customKeypad = Keypad(makeKeymap(Keys), rowPins, colPins, ROWS, COLS);

//
void setup() {
  
 Serial.begin(9600);

 servoMotor.attach(6);
 pinMode(pecho, INPUT);
 pinMode(ptrig, OUTPUT);
 lcd.begin(16, 2);

}

//

void loop() {
  
  char KEY = customKeypad.getKey();

int keyState = '1';
int lastKeyState = 0;
int keyOverwrite = '4';

while (KEY == '1'){
  delay(500);
//
  if (KEY){
    Serial.println(KEY); //this was only to verify if the thing worked, wich is not
//
  }
  
     if ((KEY == '1') && (lastKeyState = '1')){  //the problem, i can't make it exit the state '1' (LOCK)
       
     if (KEY == '2'){
       lastKeyState == keyOverwrite;
       
      }
     lcd.setCursor(0,0);
     lcd.print("--Status--");
     Serial.print("--Status--");
     lcd.setCursor(0,1);
     lcd.print("[Lock]");
     Serial.print("[Lock]");
     servoMotor.write(90);
     delay(200);
     keyState == lastKeyState;  //what i did to make it loop from here
     
     }
}

 digitalWrite(ptrig, LOW); //State (UNLOCK), i cant get it to get back here and loop here again,
 delay(2);
 digitalWrite(ptrig, HIGH);
 delay(0.01);
 digitalWrite(ptrig, LOW);
 duration = pulseIn(pecho, HIGH); 
 distance = (duration/2)*0.034;
 delay(2);


 if (distance > 20){
   lcd.setCursor(0,0);
   lcd.print("--Status--");
   Serial.print("--Status--");
   lcd.setCursor(0,1);
   lcd.println("Closed");
   Serial.println("Closed");
   servoMotor.write(90);
  }

 else if(distance <= 20){
   lcd.setCursor(0,0);
   lcd.print("--Status--");
   Serial.print("--Status--");
   lcd.setCursor(0,1);
   lcd.println("Open");
   Serial.println("Open");
   servoMotor.write(0);
  }

}
2

Welcome to the forum

Take a close look at your while loop

    while (KEY == '1')
    {
        delay(500);
        //
        if (KEY)
        {
            Serial.println(KEY);  //this was only to verify if the thing worked, wich is not
                                  //
        }

        if ((KEY == '1') && (lastKeyState = '1'))
        {  //the problem, i can't make it exit the state '1' (LOCK)

            if (KEY == '2')
            {
                lastKeyState == keyOverwrite;
            }
            lcd.setCursor(0, 0);
            lcd.print("--Status--");
            Serial.print("--Status--");
            lcd.setCursor(0, 1);
            lcd.print("[Lock]");
            Serial.print("[Lock]");
            servoMotor.write(90);
            delay(200);
            keyState == lastKeyState;  //what i did to make it loop from here
        }
    }

Once in the while loop will the value of KEY ever change to allow the loop to end ?

This part

        if ((KEY == '1') && (lastKeyState = '1'))
        {  //the problem, i can't make it exit the state '1' (LOCK)

            if (KEY == '2')
            {
                lastKeyState == keyOverwrite;
            }

is particularly silly because if KEY equals '1' then how likely is it that KEY will equal '2' ?

1 Like
3

If you’re only managing the ‘locked’ state, Why add the complexity of a keypad?
A simple button or switch can handle toggling the status.
Even simpler - if you isolate the servo with a small switch.

4

I would do that if the teacher didnt forced the class to use it for the project.
And this was my ''most simple idea'' to implement it, without knowing was everything but ''simple''.

5

I been looking at it for a while... clearly im not in a level to understand well how to use while() and a way to code what im looking for.

6

The system will be in one of 2 states, locked or unlocked so you could use the state of a boolean variable to signify the state. Name the variable doorLocked and set it to true (locked) or false (unlocked)

Now the code looks something like this pseudo code

start of loop()
  read the keypad
  if doorLocked equals true
    //code here to unlock door if correct key has been pressed
  else  //door is unlocked
    //code here to lock door if correct key has been pressed
  end if    
end of loop()
1 Like
7

Get back to basics..
Load the simplest keypad example you can find…

Get that working, the rest is trivial to setting up the key matrix and parser.
Once you can see the 1/2 keys, the rest is simple.

Use serial.print() to debug your progress.

8

look over this simple lock logic and how the keypad is used

// simple lock

# include <Keypad.h>

const byte ROWS = 2;
const byte COLS = 2;
char Keys[ROWS][COLS] = {      //only using 4 keys from a 4x4 keypad.
    {'1', '2'},
    {'4', '5'},
};
byte rowPins[ROWS] = {16, 17};
byte colPins[COLS] = {14, 15};
Keypad customKeypad = Keypad (makeKeymap (Keys), rowPins, colPins, ROWS, COLS);

char keyLst;
bool unlocked;

// -----------------------------------------------------------------------------
void loop ()
{
    char key = customKeypad.getKey ();
    if (keyLst != key)  {
        keyLst = key;

        if ('1' == key)  {
            unlocked = false;
            Serial.println ("  locked");
        }
        else if ('2' == key)  {
            unlocked = true;
            Serial.println ("  un-locked");
        }
    }

    if (unlocked)  {
        ;       // do something
    }
}

// -----------------------------------------------------------------------------
void setup ()
{
    Serial.begin (9600);
}
1 Like
9

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.