Connecting my fish tank to the Internet of Things – Part 1: Hacking an automatic fish feeder
I bought a used automatic fish feeder from ebay. This device is completely mechanic and very old (older than 1989). It has 27 containers for fish food and a disc that does one rotation per day. By sticking pins into that disc one can trigger one or more feedings per day. A pin will rotate an outer ring with the containers by one unit. One container always faces down, emptying its contents. So if the outer ring has made one revolution, all containers have been emptied.