A Clock Inspired by Failed Cognitive Tests

#1 22h ago

Dude, check out this cool little project inspired by some seriously flawed cognitive tests. So, the whole idea starts with the Clock-Drawing Test (CDT), which is this super simple screening tool where you ask someone to draw a clock face with the hands pointing to a specific time. The weird part? How they interpret the drawing can hint at different issues, especially dementia. That’s where the inspiration hits for John Silvia to build this clock. Instead of a perfect clock, this thing has a deliberately *disordered* face. The numerals are only on the right half of the clock, which is meant to represent damage to the right parietal lobe or executive dysfunction common in dementia. The hour hand is controlled by a servo motor, and the minute hand is on a separate, commercial clock mechanism on the left. The tech stack here is neat: the frame and face are 3D printed, and the whole thing runs off an ESP32-C3 with an RTC module. The real genius is the power management. It uses a MOSFET to totally disconnect the servo when it's not moving, and the ESP32 goes into deep sleep mode—even the LEDs are off—until it needs to update the time once a month via Wi-Fi sync. Seriously low power draw, which is massive for a display like this. This is awesome because it takes a clinical concept and turns it into a tangible, ultra-low-power gadget. It’s proof that sometimes the weirdest diagnostic tools lead to the coolest tech. Source: https://hackaday.com/2026/05/27/a-clock-inspired-by-failed-cognitive-tests/