This Instructable will show you how to make a password locked safe using a keypad. The code can be changed in code to anything you want. This model is only a prototype and is not intended for real use as the materials do not resemble that of an actual safe. This safe uses Arduino.

Step 1: Circuit

These are some pictures of the circuit. Since the circuit is very complicated these will help for the breadboard and arduino portion of the circuit. For the certain parts of the circuit such as the relay module, the keypad, servo, and LCD display there are separate tutorials on how to attach the wires to them as they all follow similar procedures. The two buttons can be used for custom procedures that are up to you if you build this by editing the code.

Here is a list of important parts needed for the safe:

- Relay module

- LCD liquid crystal display screen

- Button keypad 4x4 buttons.

- 180 degree servo

- 2 buttons (optional)

- Buzzer

Step 2: Making Parts for the Model

The material of the safe is high quality foam board. I used roughly 3 full sheets to create the whole safe. The dimensions of the safe are 30 cm x 30 cm. The safe is cube shaped.

Here is list of each piece used:

- 30 cm x 30 cm piece, 6 used

- 10 cm x 4 cm piece, 4 used

- 15 cm x 4 cm piece, 2 used

*Some of these parts can be seen in photos of the safe in this instructable

Step 3: Assembling the Outside of the Safe

Now that all the pieces are made, it is now ready to be assembled. A glue gun is useful for this part but it depends on the material you are using. A glue gun is recommended for the foam board material.

Step 1:

Begin by using 5 of the 6, 30 cm x 30 cm pieces. Make a box shape and make sure each side is glued except for the 6th piece which is the door. This piece should not be glued on.

Step 2:

Next take the 2 hinge pieces (10 cm x 4 cm) and cut a slit about halfway through the piece, make sure to not simply cut it in half because this will not work. Next glue these pieces one side of the wall, where you want the door to open. Then glue to door to these pieces.

Step 3:

Take another 10 cm x 4 cm piece and cut it in half, then glue on horizontally on the outside of the door and the other piece on the piece you just glued but make sure it is sticking out towards you. This will be the handle for the door.

Step 4: (optional)

Cut a small hole in the back of the safe for the connector cable if you are using one to attach to the Arduino.

Step 4: Making the Locking Mechanism

Now that the outside of the safe is complete, now it is time to make the inside.

Step 1:

Take the last 10 cm x 4 cm piece and glue it to the wall at the end of the door side. Then one of the 15 cm by 4 cm pieces and glue it to the back of the first piece but vertically. Trim the piece if it does not touch the roof of the safe, make sure you glue it to the top. (If confused, refer to the picture with the 2 pieces on the inside for clarification).

Step 2:

Glue the last piece of foam board (15 cm by 4 cm) to the servo and glue the servo to the inside of the door. Make sure that the servo is on the same level as the locking mechanism. (If confused, refer to the picture with the servo attached to the door and the piece attached to it). The servo should be closer to the wall side rather than the locking mechanism side. To see if it locks, see if the bar lines up with the bar attached to the wall.

Step 5: Clarification Picture

Step 6: Attaching the LCD Display and Padlock

Make sure to measure the LCD display and Padlock you are using as the sizes can vary. To attach them simply cut out the same dimensions of these components from the door and then insert them. There mat be an excess of wires sticking out so make sure to make extra room if that is a problem.