Advertisement

After writing about ESPHome projects for what feels like an eternity, there is finally one with a creative name: The MIST-O-Matic 3000. This fun little device is exactly what you’d expect it to be: A smart, Wi-Fi connected humidifier. At the heart of the MIST-O-Matic 3000 is the beloved LOLIN (previously WEMOS) D1 mini (official AliExpress store) running firmware built using ESPHome. And it wouldn’t be an ESPHome project without any RGB illumination, right? To solve that problem, a NeoPixel Ring with 24 WS2812B LEDs is built into the base.

Advertisement
The MIST-O-Matic 3000, a smart and Wi-Fi connected ultrasonic humidifier

Different to many of the other projects I’ve featured in the past, this one started as an attempt at reverse engineering an existing humidifier. That however turned out to be too complicated due to the use of a custom controller. In the end the easiest option for the creator of this ESPHome project was to build the whole thing from the ground up using parts from AliExpress and our favourite Swedish furniture store, IKEA.

Parts needed for the smart and Wi-Fi connected humidifier

Besides the aforementioned LOLIN D1 mini, the smart and Wi-Fi connected humidifier needs a number of various parts. The mist is created using an ultrasonic humidifier. These use high-frequency sound vibrations to produce what is essentially very fine water mist. Unlike with an evaporative humidifier, there is no heat involved, as there is no need to boil any water for the mist. The ultrasonic modules can be found for little money on many online marketplaces, such as AliExpress.

Advertisement

To move the mist out of the container and in to your space, a small blower-type fan is used. This fan blows air in to the container so that the mist has only one place to escape: The opening in the top. To prevent the humidifier running out of water, a floating water level switch is placed in the water. These turn on or off, depending on how high the water is.

As you might have already guessed, this project uses multiple 3D-printed parts. Namely, the base and its cover, the diffuser base, the top cover, and the water level sensor. In the base there are also two buttons for manual control: One controls the humidifier and the other the LEDs.

SaleBestseller No. 1
Official Creality Ender 3 3D Printer Fully Open Source with Resume Printing Function DIY 3D Printers Printing Size...
  • Resume Printing Function: Ender 3 has the ability to resume printing even after a power outage or lapse occurs.
  • Easy and Qucik Assembly: It comes with several assembled parts, you only need about 2 hours to assemble 20 nuts well.
SaleBestseller No. 2
Official Creality Ender 3 V2 Upgraded 3D Printer Integrated Structure Design with Carborundum Glass Platform Silent...
  • Self-developed Silent Motherboard: The Ender-3 V2 built-in self-developed silent motherboard, which has stronger anti-interference, faster and more stable motion performance, silent printing and low decibel operation.
  • UL Certified MeanWell Power Supply: Equipped with MeanWell power supply, produced by the listed company with mature technology, meeting all the needs of fast heating and long-time printing. Moreover, the power supply is concealed in the machine, making it much safer.
Bestseller No. 3
NantFun DIY 3D Printer for Kids, Mini 3D Printer for Beginners, Upgraded Extruder Technology Small 3D Printer Fast...
  • [EASY TO USE] - The mini 3D printer is super easy to use, children and beginners are able to grasp it quickly. The accuracy is as low as 0.1 mm, which allows a smooth and alive printing effect. It's an excellent tool for kids to develop interest and improve spatial imagination. Note: This mini 3D printer does not have the function of resume printing, it will print from the beginning when there is a power failure.
  • [Quick assembly] - The mini 3D printer diy kit consists of 2 main parts. Usually it can be assembled in just 5 minutes according to the assembly video (included with TF card and product page). It is easy to use even for children. You can print the attached model or your own design. Note: The filament holder can point inwards or outwards, which does not affect the use.

How the smart and Wi-Fi connected humidifier works

The wiring might look rather complex at first sight, however it is easily explained. The power supply for the Wi-Fi connected humidifier provides 24V, which is what the ultrasonic humidifier and the fan need. To not destroy the ESP8266 board and LEDs, .

Advertisement
The schematic for the smart and Wi-Fi connected humidifier using ESPHome

The fan and the ultrasonic humidifier do not have variable levels of operation. They are either on or off. To allow the ESP8266 board to toggle them, two TIP120 NPN transistors are used. The buttons and the water level switch are attached as you would attach any button.

How the smart and Wi-Fi connected ultrasonic humidifier could be improved

In my eyes, this ESPHome project is missing a humidity sensor. Using such a sensor, the whole thing could be configured to turn on whenever the humidity reaches a certain level. Then again, it might be better to measure the humidity at the other end of the room, to see how well the humidifier is performing.

While the exterior of the smart ultrasonic humidifier does look very clean, it could further be improved by using a capacitive touch switch. Though I can’t be sure these wouldn’t be triggered by the ultrasonic module.

Of course, you also have the option to build a larger smart humidifier. All you need is a larger water container and multiple ultrasonic modules.

Advertisement
Liam Alexander Colman, the author and maintainer of Home Assistant Guides.

About Liam Alexander Colman

Liam Alexander Colman has been using Home Assistant for various projects for quite some time. What started of with a Raspberry Pi quickly became three Raspberry Pis and eventually a full-blown server. I now use Unraid as my operating system and Home Assistant happily runs in a Docker container. My personal setup includes many Zigbee devices as well as integrations with existing products such as my Android TV box. Read on to find out more on how I got started with Home Assistant.

Leave a comment

Advertisement