Arduino Locking Safe

This Arduino locking safe is a secure and innovative way to store valuables. Utilizing circuits and a locking mechanism, this Instructable will teach you how to build one of your own!

Here is a breakdown of the costs associated with creating our safe. However, each safe design and project are subject to changes in price and materials used. Our team was able to receive all the parts through our university, except for the ELEGOO UNO kit. This kit was required for previous classes and you may already have the parts necessary.

Parts required from the kit:

1. Arduino or ELEGOO Uno or equivalent
2. Membrane 4x4 Keypad
3. LCD Display
4. Assorted Wires
5. L293D Motor Driver

Make sure you have the following equipment on hand:

1. Computer with the Arduino IDE software and a 3D printing slicing
2. Hot glue gun
3. Small screwdriver set
4. 3D printer
5. Nuts & bolts/screws
6. Tape
7. Hinges
8. Laser Cutter/ Water Jet

Use CAD software (like SolidWorks) to create a basic idea of what you want the safe to look like. Be sure to take into account functionality and additional attachments that will be added later. Our basic design was made with laser-cut wood and 3D printing technology; however, this can be any material you like. Be sure the final design has these properties:

1. Drop-resistant
2. Unable to access from outside the safe

You will be creating your own safe, and your next step is to design your parts using CAD software, like SolidWorks. This will provide a visual of what you will be constructing. If you do not have access to CAD software, you can try sketching your idea by hand, but this is not the most practical or effective method. Then, begin collecting the materials and parts required to make your safe. In the Materials section, we list the components that go into constructing the safe. Be sure to get what you need before beginning assembly.

If you are using a 3D printer, you will first need to upload your STL file into a software application, such as Cura. The STL file contains all the required information to enable the printer to print your parts. Then, the 3D printer prints the individual parts for your safe.

The power source you use to power your safe can be anything, as long as it falls within the 5.5V-12V range. However, once you’ve connected your power source, be sure that the Arduino you are using is getting power. It should be indicated by the green light on the Arduino Uno.

In order to make your locking safe, there are a few things that need to be considered. First, you will need to test your circuit. You can do this by following the schematic that we have laid out. The easiest way to test your code is by breadboarding the circuit. After you have successfully run a test circuit, you can start working on a PCB. Ideally, you can attach the Arduino to the inside wall of the locking safe to save space. You can then organize the wiring easier. KiCad and SolidWorks are both free software that is useful for this kind of design. If you are at a university, you may be able to use the resources there to create the board as well.

If using the Arduino-based version of this locking safe, ensure your Arduino is powered on with the green light present. This is usually achieved with the Arduino connected to the USB port of the computer. Then, assemble the locking safe by adding all of the components. Once the safe is assembled, you can test its functionality by attempting to open and close the safe multiple times. You can also test the locking mechanism by inserting the correct password and seeing if the lock unlocks the safe.

Upload the correct code and ensure that it runs smoothly before sending it to your car as a final product. Function check and test all controls before finalizing your code! This was the code that we used for our safe!

Finally! Your locking safe is now finished! We tested each part and functionality to make sure the final product works. So, insert your valuables and enjoy your new Arduino locking safe!

Here are some videos of our safe in action!