This is my attempt at creating an open source controller for the LitterRobot3, a very expensive but incredibly useful addition to my house with 3 cats. Or at least it was very useful when it was working. It has been acting up for a while, and I’m not entirely sure what the problem is yet. The existing controller shows signs of being cooked alive, but it seems to function as intended, no magic smoke has been released yet anyway. The problem seems to be with the system that tells the controller when the waste drawer is full, the drawer full indicator system (DFI). The system seems to constantly think the waste drawer is full, and thus will not cycle. I could buy a new DYI system for $90 CAD plus shipping, but that might not even be the problem. I could also buy a new controller for $100 CAD, but it doesn’t SEEM to be the problem. So I could potentially put $200 into this already expensive litter box, and hopefully end up with a working unit. Or I could try something else entirely.

This is where a new controller comes in. The Litter Robot 3 already lacks some features that I would like to have. I’ve toyed around with this idea from day one, but couldn’t justify it while the unit was still working properly. Now that I have a problem to solve however, all bets are off.

My plan is to design a new controller that would allow me to integrate the litter box into my home automation system. My plan right now is to base the controller around an ESP32, which would allow me to write the firmware in (micro) Python, and add an MQTT interface with the built in WiFi. As my last post went over, it’s really easy to get Python working with MQTT. I suspect microPython will be a bit more challenging, but it should be similar enough.

I’m keeping the project on GitLab, but I plan to have a few posts that go into some more details that don’t easily fit into a git repo. Right now I have schematics for the LR3 harness mostly mapped out, as well as a prototype controller that is based on an Arduino Nano. The prototype is mostly a proof of concept, it doesn’t add any new features. So far the prototype cycles the litter box 7 minutes after it’s been used, and auto stops if a cat jumps in while it’s rotating. So while I don’t know if the drawer is full, I’m no longer spinning the globe manually! 🙂