While making your own locking system can be quite tricky, not all of them need to be of the highest security possible. Sure, if you're creating, say, a lock to protect your property or your deepest, darkest secrets, then, yes, you'll want to go all out on the details and buy only the best components. However, if you're making something just for fun, where the contents aren't incredibly important to your well-being, you don't need to splash out for it.

For example, what if you're making a cool prop for an escape room, or for your next TTRPG adventure? Well, if you're on the hunt for a lockbox that may not be the toughest lock in the business, but still acts as a fun puzzle for people to solve, you can do worse than this cool ESP32 project that costs less than $30.

This ESP32 lockbox makes for a fun little puzzle

And it's cheap to boot

As spotted by Hackaday, this cool project was the idea of Chad Kapper over on HackMakeMod. They wanted to make a fun lockbox for an escape room puzzle, and they wanted to get something functional up and running without spending too much money. To achieve this, they enlisted a device called the "Cheap Yellow Display," or CYD for short. As Chad puts it:

The CYD is infamous in maker circles. It’s a low-cost ESP32 development board with a 240x320 touchscreen, WiFi, a speaker output, and a few extras. Dozens of manufacturers produce slightly different versions, and the documentation is often incomplete or flat-out wrong. It’s not exactly a polished product… but it’s cheap, it works (most of the time), and with a little creativity you can squeeze surprising value out of it.

For this project, Chad wanted to put the CYD to good use and see what it can do. Chad noted that the entirety of the CYD's screen has touch controls, which made it really easy to make a numpad. That way, you could devise an escape room that involves finding a four-digit code, then have the solver enter it into the box to access its goodies.

However, because it's a touchscreen and not a physical keypad, you could theoretically put anything you want on it. Maybe you can make a code based on shapes, or have a simple sliding tile puzzle that someone has to solve to open up the chest. There's a lot you can do with this kit, and with Chad claiming that the whole thing cost them less than $30 to make, that's an excellent price for a fun project like this.

If you like ESP32s and saving your money (and who doesn't?), be sure to check out these cheap ESP32-based display projects anyone can build.