Keep forgetting the fan and getting mold in the shower? This is the solution

When Manivannan moved to the UK from India, he found that the damp winters provide the perfect conditions for mold growth in the shower. The preventative solution is to run the ventilation fan when showering, but that is easy to forget. So, he built the AntiMould Shower Sentinel to ensure discipline.

This device’s purpose is to sound a warning alarm if the user runs the shower, but doesn’t turn on the ventilation fan that is necessary to prevent mold. When it determines that the user has failed to turn on the fan, it sends a notification to the user via Home Assistant. 

You might be wondering why the device wouldn’t simply turn on the fan itself, because that would solve the problem in a more convenient way. But that would also require modifying the fan’s mains power wiring, which isn’t an option for most renters. Manivannan’s solution doesn’t require anything but Wi-Fi, a USB-C power supply, and a microphone.

That’s because it works using an Arduino UNO Q, which runs a machine learning model deployed via Edge Impulse. That model leverages the microphone to listen to the ambient sound and recognizes the acoustic signature of a running shower. If it hears that, it then checks to see if the fan is running. If the fan is on and continues to stay on for at least 20 minutes, then all is well. If those conditions aren’t met, the user gets the notification through Home Assistant.

It is impressive that Manivannan found an affordable and unobtrusive way to detect the shower and fan states, all in a compact package that doesn’t require any installation steps that might upset a landlord.