Tactile Thermometer-Clock

Hi!

I made this device, a thermometer-clock without screen, buttons, needles or any visible interface.

It may not be the most practical device, but we can’t deny that it’s a cool idea. 😎

I think it might be a good device for people who live far from home and want to feel a "physical" bond with their place of origin.

It's based on a NodeMCU, a peltier plate and a solenoid, and uses a PID system to reach the target temperature accurately.

BOM:

-NodeMCU.

-Solenoid.

-Peltier plate.

-BTS7960-43A cd-motor driver.

-MAX31855 Thermocouple Amplifier.

-Mini 360 dc buck converter.

-2 x irlb8721 mosfet.

-2 x 1KΩ resistor.

-1 x 1MΩ resistor.

-Piezo disk.

You can find the sketch and the stl files here: github.com/sagarrabanana/notJustAnotherKnockClock

In general terms, the operation of the program would be as follows: First, the device is connected to the Internet, once connected it stays listening to the piezo, if we knock the box twice, it'll use the "NTPClient libraries. h" and "WiFiUdp. h" to consult the time. Once it reads the data, translates the result to "bell towers" style and expresses it through the solenoid.

On the other hand, if the piezo detects three knocks, the device will check the temperature in the target city, using the openweather API. Once it gets this the data, it turns on the peltier plate. This plate is controlled by a DC motor driver. The program will use the ambient temperature as a reference to decide whether the plate should be heated or cooled to reach the target temperature. All this will be regulated with a PID system, having a continuous feedback of the thermometer placed between the peltier plate and the aluminum plate. Once the target temperature is reached, you will notify using the solenoid.

Here you can find more details about the process. (English subtitles).

I hope you like it!