The Tactile Clock-Thermometer

from hackster.io

Creating your own clock seems to be something of a maker rite of passage, and while most have a visual indicator of some kind, this timepiece by Sagarrabanana does not. In fact, it simply looks like a well-made, if curious box, with a 3D-printed base, a few aluminum pieces, and a top mostly cut out of wood.

Tap twice on the top, however, and you’ll get some indication of what it does, as it taps back in an hours-and-minutes pattern like clock chimes. Tap three times, and the aluminum section on the top becomes hotter or colder to indicate the outdoor temperature.

A NodeMCU ESP8266 dev board is the brains of the operation, pulling the time and weather stats off the Internet, and a piezoelectric sensor is implemented to detect knocks. Tapping back to indicate the time is accomplished by a solenoid, and heating/cooling of the aluminum plate is via a Peltier device.

The Peltier heater/cooler is hooked up to a motor driver, which can regulate the power as well as the polarity as needed to produce the correct temperature at the pad. A thermocouple provides closed-loop feedback, and PID control is implemented so that the temperature doesn’t just bounce up and down.

On the surface, it seems like a rather fun and silly design, but perhaps these concepts could have implications for those with visual or even auditory impairments. Check out the build video – in Spanish with English subtitles – for more info!