Cat Litter Box Smart Monitoring

Feb 01, 2024

While cats are relatively self-sufficient compared to their canine counterparts, they do require repetitive litter box maintennance. If you’d like to know exactly when your feline friend has done its business, and even track its patterns over time, then this NodeMCU sensor package from Owen Ashurst is a simple solution that can be made for £10.18, or around $13.

The project employs a NodeMCU ESP8266 dev board for communication and control, and an AM312 mini PIR sensor to detect when the cat has entered its chamber. An MQ135 air quality sensor measures the cat's effect on the immediate atmosphere, allowing it to detect when an “event” has taken place.

The litter box unit transmits data to Ashurst’s Home Assistant instance via MQTT, which is set up with automations for motion detection and when the air quality level switches from good to… moderate. Home Assistant sends out a notification when an “atmospheric event” has taken place, letting Ashurst know that there is a task to be done when he gets home.

In addition to providing immediate notifications, the setup also tracks usage stats over time. This could certainly be helpful for the veterinarian in certain instances.

The whole system is put together on a piece of perfboard, and power is provided through an external USB plug somewhere on the outside of the box. Code is available here if you would like to try something similar.