Engineering feedback needed: IoT-based autonomous public toilet maintenance system.

Hi everyone,

I am working on a prototype for an IoT-based autonomous public toilet maintenance system aimed at improving hygiene and reducing the need for manual monitoring. The idea is to use an ESP32 microcontroller connected with multiple sensors to automatically monitor usage and environmental conditions inside the toilet.

The system includes a PIR sensor to detect user presence, an IR footfall counter to track the number of users, an MQ135 gas sensor to monitor odour levels, and water level and flow sensors to track water usage. After each use, the system automatically triggers a flush and releases a small amount of disinfectant. If gas levels increase beyond a threshold, an exhaust fan and deodoriser system are activated to control odour.

The system also sends real-time data such as usage count, gas levels, water levels, and cleaning cycles to a cloud dashboard for remote monitoring. The entire setup is intended to run on solar power with a battery backup so that it can operate in areas with unreliable electricity.

I would really appreciate feedback on the design. In particular, I would like to know if the selected sensors are suitable for this application, whether there are better methods for odour detection, and if there are any improvements that could make the system more reliable for real-world deployment.