Cabe Atwell loves his goldfish. If there's one lesson to learn from this project, that's definitely it. Goldie is the name of the beloved scaly wonder who captured Atwell's heart. And when Goldie fell victim to attacks by the other fish, Atwell's heart was broken. However, thanks to Atwell's love, devotion, and Raspberry Pi, Goldie is living healthy and strong.
Atwell had a list of problems that needed urgent attention. Not only did his beloved goldfish have crippling physical mutilation, but she also had an infection. Atwell knew he hadn't been keeping close enough tabs on her tank parameters such as nitrate and ammonia accumulation -- or even temperature. All these things are notoriously difficult to manage in a small aquarium with one goldfish, let alone two.
People often tell me that they kept a goldfish in a bowl without a heater, filter, or plants for years, and the fish was fine. Sorry, but you were actually torturing and then killing your fish. Just because it couldn't tell you its life sucked didn't mean you gave it optimal living conditions. (I'm staring at you, person with a betta in a cup.) Don't argue. Do some research, feel bad for a little while, and just promise never to do it again.
Atwell took action. He came up with a system to supply much better living conditions for Goldie. He set out with the following goals for his system:
To see Goldie remotely in real-time
To control the camera's location
To cut the power to the tank's filters and air bubbler
To feed Goldie at will
To sense the tank temperature
Above all, to do all this through a network -- and ultimately via the Internet
To achieve this, he used a mixture of the Raspberry Pi and an Arduino. He was going to need motor control, relay control, a moving platform, a temperature sensor, and a camera feed. The motor control and most other external items were handled by the Arduino, while the Raspberry Pi handled the video feed and put everything together for Atwell's interaction. You can see his schematics and logical diagrams on the project's page.
Atwell says this project is far from over. Though he has met his initial goals, he obviously wants to keep improving the system. Things like monitoring the ammonia in the water and sending alerts when it needs to be refreshed are next on his list.