Litterbox Monitor: sensor prototyping

I’m developing a fume-activated litterbox monitor (i.e. “your cat’s box smells bad! time to clean it!”). I’ve devoted this first prototyping to achieving full functionality in my sensor in the breadboard phase. As you can see* in the video below, I have:

Here’s a clearer look at my breadboard wiring:


And here’s a glimpse into the process whereby I concocted a water-ammonia solution with roughly the same ammonia levels as cat urine:


Healthy cat urine is allegedly .05% ammonia, among other things. So I combined 2 liters of water with 1 milliliter of ammonia to simulate cat urine. However, this concoction was too mild to impact the gas sensor enough to create a spike in the serial output, so I ended up just doubling the “resting” threshold as my “stinky-enough” benchmark.

Here are my envisioned next steps:

  • Incorporate a smaller Arduino board for a sleeker profile
  • Consider the inclusion of a WiFi-capable Arduino board, explore transforming output from LED ignition to SMS sending (i.e., “time to clean the litterbox!”)
  • Develop a chassis that can encompass all these components, convey the utility (cat-shaped?), and inspire admiration

Please  let me know your thoughts or suggestions in the comments!



*I hope! My LED is rather dim in this lighting.