Fish feeder - designed for aquarium.
Its operated with small SG90 micro servo 9g and Arduino Nano.
You power whole feeder with USB cable (from USB charger or USB port of your PC)
By simple editing program you can set exact times of feeding set on exact hour minute.
And how many doses of food they get per feeding.
// You can set times when you want to feed your fish
char feeding_times = "08:00:00,12:00:00,18:30:10,21:30:00";
int count_of_doses = 10; // how many doses should fish get per feeding
Whole instructables are here: