I Turned a Battery-Powered Air Wick Into a Smart Home Device Using ESPHome

This project started with a simple problem.

I was using an Air Wick automatic air freshener at home, but I was tired of replacing batteries and being limited by the built-in timer options.

Instead of buying a new smart air freshener, I decided to reverse engineer the original Air Wick unit and replace its electronics with an ESP8266 NodeMCU running ESPHome.

The original spray mechanism and motor were kept intact, while the original PCB was removed completely.

The result is a WiFi-enabled smart air freshener that can be controlled by Home Assistant, scheduled automatically, and powered directly from an AC adapter without using batteries.

Features:

- No batteries required

- ESPHome integration

- Home Assistant compatible

- Automatic spraying every 5 minutes

- Active only between 8:00 AM and 11:30 PM

- Remote control support

- OTA firmware updates

This Instructable shows the complete reverse engineering and modification process.

Materials:

- Air Wick Automatic Spray Unit

- ESP8266 NodeMCU

- 1-Channel Relay Module

- AC Power Adapter

- Jumper Wires

- Small Plastic Food Container (DIY enclosure)

- Double-sided tape or hot glue

Tools:

- Screwdriver

- Soldering Iron

- Wire Cutter

- Multimeter (optional)

- Computer with ESPHome

- Home Assistant Server

The first step is to open the Air Wick housing and understand how the original device works.

I wanted to identify:

- The motor

- The gear mechanism

- The trigger system

- The original PCB

After opening the unit, I discovered that the spraying process is controlled by a small DC motor and a set of gears that physically press the spray nozzle.

Before modifying anything, I spent some time understanding the entire mechanism.

I needed a quick enclosure for the NodeMCU and relay.

Instead of buying a project box, I reused a small plastic food container.

The enclosure houses:

- ESP8266 NodeMCU

- Relay Module

- Wiring

It may not be the prettiest solution, but it works very well and costs almost nothing.

The ESP8266 runs ESPHome firmware.

I created a relay switch and a virtual push-button switch.

When the virtual button is activated, the relay powers the motor briefly, which triggers a spray cycle.

This approach allows Home Assistant to trigger the original Air Wick mechanism without modifying the mechanical design.

Home Assistant handles the scheduling logic.

Current configuration:

- Spray every 5 minutes

- Active only between 8:00 AM and 11:30 PM

This gives much more flexibility than the original Air Wick timer.

After testing everything, I installed the modified Air Wick in its final location.

The unit is now powered directly from an AC adapter and operates automatically every day.

No more battery replacement and complete Home Assistant integration.

The project has been running reliably and achieved all original goals.

Benefits:

- No batteries

- Smart scheduling

- Home Assistant integration

- Remote control

- Reuse of existing hardware

Future improvements:

- Spray level monitoring

- Refill detection

- Occupancy-based spraying

- Air quality sensor integration

- Custom PCB design

This project shows that many commercial devices can be upgraded rather than replaced.