Halloween Trick or Treater Mini Escape Room Puzzle

This last Halloween I build a simple escape room puzzle and left it out for trick or treaters, with a grand prize inside for the first group to solve it. I didn't think anyone would really notice it, much less solve it. I was so wrong! The trick or treaters loved the puzzle! Even after the grand prize was taken, there were trick or treaters who were determined to come to my house first next year so they could try again!

Here is the original video of the puzzle in action:

1. Instagram
2. TikTok

This tutorial will go through how I built the keypad and electronic lock mechanism. This tutorial will NOT go through how I built the blinking pumpkins from the video, I will create a tutorial about those at a later date. As is, this tutorial is already really long and I didn't want to continue overcomplicating it.

IMPORTANT: I will do my best to approach this tutorial as if you've never touched an electronics project before. You should be able to follow along step by step and recreate this build on your own with no experience. If you're new, please don't be intimidated! The best way to learn something new is to challenge yourself. And if you follow along, you should be able to build something really fun! For more experienced enthusiasts, the YouTube tutorial will probably be a little slow for you so feel free to skip ahead as needed.

Here is a link to my Amazon Storefront, which contains everything you will need for this build (minus a cabinet that you will install the puzzle in):

Amazon Storefront Link - A lot of the parts come in bulk which is unfortunate. But if you're going to continue building projects like this then you might want to get a little storage bin to store the extra parts!

In many cases you can find the exact same electronics parts from AliExpress for MUCH cheaper, so feel free to try an source the parts there.

I will also list the parts below in case my Amazon Storefront link breaks, or you want to find the parts yourself:

Tools:

1. Soldering Iron
2. Solder
3. Soldering Tip Cleaner (not required, but nice for keeping your soldering tip clean)
4. Wire Strippers
5. An electronics screwdriver set (just a small screwdriver)
6. Little snippers/scissors

Parts:

1. 1 x 12V Power Supply
2. 1 x Solderless Breadboard (aka Prototype Board)
3. 1 x Breakaway PCB Board Pins (Male)
4. 2 x Wago Lever Nut (for joining just two wires, this is not necessary, you could also just solder the wires together or use wire nuts)
5. Low voltage 22/2 power cable (red/black)
6. Solderless Breadboard Jumper Cables
7. 2 x Small compression springs
8. 1 x LED (must be < 5V)
9. 1 x 5V Relay Module
10. 1 x Steel Solenoid Cabinet Spring Lock
11. 1 x Arduino Nano (or similar clone board)
12. 1 x 3x4 MCU Board Matrix (if you do not buy the exact same one as me, then your pin layout may be different)
13. 1 x 220 ohm resistor

This tutorial will go through how to connect a keypad, an LED, and an electronic lock to an Arduino. When a secret code is entered, the lock should be released; unlocking whatever it is attached to.

It is up to you to decide where to install that puzzle though! In my example I am using an old nightstand that was being thrown out. You could install it to open a drawer, a door, a box, etc. You will want to have a plan around what is going to be opened when the puzzle is solved before you start.

Copy and save this code for later in the video tutorial. You will need to upload this code to your arduino.

I've posted the code in GitHub: Click Here to navigate to the repository.

If you want to 3D print the enclosure I designed for the keypad, attached is the STL file. Once it was printed, I just marked and drilled holes to secure the keypad with M2 screws. I also drilled a hole for the LED and hot glued it in.