Chad Kapper Turns a Cheap Yellow Display Into a Low-Cost Lockbox Escape Room Puzzle
A Cheap Yellow Display, a solenoid, and a battery pack deliver a slick code- or puzzle-based lockbox for an escape room experience.
Maker Chad Kapper has built a code-entry lockbox for an escape room game — and rather than opting for the usual physical keypad, put a touchscreen Cheap Yellow Display at the heart of the project.
"Would you believe this touchscreen escape room lockbox cost less than $30 to build? The key to pulling it off is a quirky little board known as the CYD (Cheap Yellow Display)," Kapper explains. "The CYD is infamous in maker circles. It's a low-cost [Espressif] ESP32 development board with a 240×320 touchscreen, Wi-Fi, 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."
The Cheap Yellow Display is more properly known as the ESP32-2432S028R, with its easier-to-remember moniker coming from the usual yellow PCB on which it is built. The rear of the board features the Espressif ESP32 module that powers the device, along with various ports and a microSD card slot, while the front is dominated by a full-color 2.8" 240×320 touchscreen display. With an integrated microcontroller and Wi-Fi connectivity, it's ready-to-run with no external components required — and as it can be purchased for as little as $15, or less if you can hunt down a bargain, it's a popular choice for a range of projects.
In Kapper's case, the project is a lockbox designed for an escape room game: enter the code to open the box and win your freedom. "I used the CYD as a touchscreen keypad to unlock a solenoid lock. Tap in the right code and the box opens. Simple idea, but with a ton of room for expansion," Kapper explains, suggesting future alternatives to a traditional numerical keypad that could include puzzle-based locking systems with pattern-matching and sequence-continuation tasks.
"I plan to experiment with different puzzle types, starting with shape sequence challenges (like IQ test patterns)," Kapper explains. "The idea is that you'd need to solve three in a row to unlock the box. Because the puzzles are randomly generated, it's never the same twice."
More information is available on Kapper's website.