Building a Better Cat Bathroom

Filed Under Gadgets & Hardware, Geek, Lifehacks on 2014-04-21, 14:19

Bunki peeks in Cat Bathroom

I’ve had cats for many years. This means I’ve had to deal with litter boxes for just as long. When you have one cat, it’s not a big deal. However when you have three of them, like we do, the litter box challenges are greater. For years I dreamed about solving all of these challenges with the perfect litter box situation. We haven’t quite achieved that level of greatness, but what we’ve put together is pretty damn close.

With 3 cats we’ve had 2-3 litter boxes. They’ve been placed in laundry rooms, bathrooms, kitchens, closets, showers, tubs, and just about anywhere in an attempt to make them work. Up until now we rented, so we never wanted to invest the time or money into a more permanent solution. Plus none of our rental apartments had the space for it! When we finally bought a house last year, we resolved to finally solve this problem: Introducing the Cat Bathroom.

The Cat Bathroom was originally designed as an additional room with framing and doors and whatnot, but then we found a garden shed that was the perfect size. It comfortably holds 3 litter boxes and gives the cats plenty of room to walk around and do their business. In a single afternoon we assembled the shed, cut a hole in the side with a jigsaw, and then cut a hole in the wall between our downstairs room and the garage so that we could install the cat door. The cats love it, and we’ve had almost no “registering of complaints” in other areas of the house.

Inside the Cat Bathroom 2

Inside the Cat Bathroom we have three litter boxes. One of the litter boxes is a Litter Robot, which cleans itself. I highly recommend these if your cat will use it. Some of our cats aren’t as fond of it, so we’ve still got two normal boxes. In order to get into the Cat Bathroom, the cats have to climb through the pet door. Since it’s not level with the ground, the cats don’t track the loose litter out into our living space. No longer do we have to step on litter when using a “shared” bathroom barefoot. The shed also has two large doors that swing open and a hydraulically assisted lid that allows for super easy cleaning of the boxes. Because it’s already in the garage it means we never have dirty litter sitting in the house waiting to be taken out.

Exhaust Fan

We learned a very important lesson after the first few days of the Cat Bathroom: ventilation is important. The smell of opening the lid after the first few days was overpowering. A simple exhaust fan found on Amazon and some more jig saw cutting and that problem was easily solved. It exhausts into the garage, which has enough air flow that the smell is never noticed. Gone are the days of nice dinners ruined by the smell emanating from the corner of the kitchen.

Most people would probably stop with that setup and call it good. However I’m not “most people” and wanted to make it a little bit fancier. I’ve already implemented a large amount of home automation with Insteon/X10 hardware and Indigo software. Since I already had that all setup, and I had a leftover X10 motion sensor, I decided to use it — in conjunction with Splunk — to track how often the cats used the litter box. It was an excellent way to make sure full adoption of the Cat Bathroom was happening at the beginning.

Cat Bathroom Visits

The X10 motion sensor sits right inside the door, so the cats trigger it whenever they walk in. It sends a signal to an X10 receiver, which is then picked up by the Indigo software. The Indigo software logs the trip, increments a variable counting the number of trips, and then calls a custom python script that posts a randomly selected message to the Twitter account setup for the @CatBathroom. The Twitter account has 13 followers. I’m still not sure why.

As part of “making sure the cats are using it” I wanted a way to know which cat was using it so we were sure all 3 of them were on board. I happened to have a Raspberry Pi and a camera module sitting on my desk. A little bit of work later and I had motion triggered video recording setup with it. As you can see, I’ve opted for the super high-tech “wad of tape” method of mounting and aiming the camera. I also found out that the Raspberry Pi camera wasn’t so hot at low-light, so I hung an LED bulb in there that’s always one. I like to think that in addition to making the camera work, it also makes the Cat Bathroom friendlier than the dark cave it used to be.

Raspberry Pi Camera

Now we have security camera style footage of the cats using the bathroom. Yes, it’s weird to watch it. If anyone needs almost 2gb of cats and litter boxes for a bizarre art project, get in touch with me. I will admit, there’s a bit of a temptation to hook up automated photo uploading to the Twitter account. Be warned.


The Cat Bathroom solved many of our problems, but it turned out that it caused one rather big one. Since the litter boxes were hidden away from sight, we had a tendency to forget about them. This meant it would be several days before we realized “oh yeah, we need to clean the litter boxes”. Needless to say the cats were a little unhappy about it. Enter an over-engineered solution…

Raspberry Pi CB Monitor

Another Raspberry Pi plus a small LCD touchscreen for display was the hardware of choice. I threw together a super simple flask based webserver that would query the Indigo API for the number of trips the cats had made to the bathroom and also calculate how many days it had been since the last cleaning. If either number gets to high, it turns red to draw attention to our lack of diligence. And there’s a button to tap when I clean the litter box, which resets the counters (and of course sends a tweet). I noticed it occasionally crashing and not reloading the page, so I tossed it on a WeMo switch so I can reset it easily.

You can check out the code I’m using over on github. I’m hoping to turn it into a more full-fledged house server with more than just the Cat Bathroom status at some point.

Raspberry Pi CB Monitor Mounted 3

Another smaller problem I ran into was that the cats had learned to jump directly into the Litter Robot, bypassing the step that triggers the countdown to cleaning. This meant the Litter Robot wasn’t cycling and cleaning itself after every use. Sure I could just go in there and manually switch it off and back on again in true “IT Crowd” fashion to force a cleaning, but that’s too easy. I had a WeMo switch left over from our Christmas tree lights, so I plugged the Litter Robot into it. Now I can clean one of the litter boxes from my phone.

So what’s next for the Cat Bathroom? RFID collars and litter box weight analysis are just some of the suggestions I’ve heard. But I wouldn’t want to get too carried away with this…

Cost breakdown
Suncast 3′ x 8′ x 5.11′ Storage Shed – $350
Pet Door – $88
Cabinet fan for exhaust – $35
Raspberry Pis, camera, LCD, motion sensor, WeMos, etc – [REDACTED]

Not stepping in cat litter when getting out of the shower: Worth every single penny.

The Cat Bathroom

More Pictures in the Flickr Set