Arduino Door Lock With Password





Introduction: Arduino Door Lock With Password

In this project I mede an door lock (or box lock) that opens when you enter your password and press "#". The servo turns back to the position it was in after some seconds.


For this project I used:

* Arduino uno ( )

* 4x4 matrix keypad, can also use 3x4( )

* Arduino PCB shield ( )

* 2x 1k OHM resistors ( )

* 3mm green and red LEDs ( )

* Male pin header ( )

* Female pin header ( )

* Servo ( )

* Wires ( )

The tools you are going to need:

* Soldering iron

* Soldering paste

* Soldering tin

* Plier

Step 2: Schematic

Follow the schematic.

Step 3: Solder the Connectors

Solder he connections for the Arduino, kaypad and servo. When you are soldering the connection for the keypad and the servo try not to have it in a place where the programing port on the Arduino UNO touches your soldered places, I did that once and I almost ended up destroying my Arduino because the 5v and the GND got connected together when they touched the programing port.

Step 4: Soldering

Solder the LEDs, resistors and the wires for them, than solder the rest of the wires, try to cut your wires so that they fit nice and smooth on the PCB like shown in the photos.

Step 5: The Door Lock

I mounted my servo on an aluminum plate with an simple lock. unfortunately I did not take any photos when making this but hopefully you will understand how to make it by the photo, its really easy.

Step 6: CODE

Download the code and import libraries. You need to download the 3 Arduino libraries if you don't have them.

* password.h

* keypad.h

* servo.h


Ifyou like this project than go check out my channel for more cool projects :)

If you have any questions or tips than post them in the comments.

3 People Made This Project!


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3 Questions


can ı use arduino nano


can ı use arduıno nano

Can ı use arduıno nano


hello , i made the same project , but i want to add buzzer which do a sonor signal when we enter a false password 3 times
could someone how can i do it
(am asking about the code )

dude ask once, not like 30 times

I made this the first time round and had no problem, but i wanted to use a smaller uno bored but now every time i try to upload the code i get this "\Documents\Arduino\TEST1\TEST1.ino:7:18: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]" and because of this the code isnt working right on the bored, pls can anyone help as im confused to what the issue is. thanks

C:\Users\Mahmoud\Documents\Arduino\sketch_jun13a\sketch_jun13a.ino:8:38: warning: deprecated conversion from string constant to 'char*' [-Wwrite-strings]

Password password = Password( "0000" );

Please help , this error appeared.

This instructable is very nice and perfect .

I made it .but there
is a problem in the program .

When you enter password keys and * key
the pass is accepted , but after that whenever you press

Just only * key
and no any other key the servo acts ,unless you press another key or
rest # key .

I solved the problem by inserting this line password.reset();

by this when password is accepted the program automatically resets it .



//Add code to run
if it works

myservo.write(150); //deg


digitalWrite(11, HIGH);//turn on

//wait 5 seconds

LOW);// turn off


how i connect the pins for 3x4 numpad ?

is this the full programming ???
and how the programming if i add a lcd or cctv ?
can you help me to program it ?

hello , i made the same project , but i want to add buzzer which do a sonor signal when we enter a false password 3 times
could someone how can i do it
(am asking about the code )

a little doubt here. if i press 123456789 instead of just 159 the opens. i mean the code is such that as if you press any no. having 1,5 & 9 in sequence the door opens