Automatic fish feeder

This is still very much a prototype so I wouldn't recommend it without some familiarity with ESP32 ESP-IDF if you're planning to customize anything.  That being said, it's been very handy to have for vacations.

Build

Equipment

• 1 28-BYJ-48 Stepper motor and driver
• 1 push button (2 planned for but only the load one is used)
• 1 10kOhm resistor to pull-up the button
• Micro limit switch
• Breadboard or prototype board
• ESP32 dev module
• 5v power supply
• Screws for the motor and limit switch

Software

Here's the repository:

https://github.com/ataboo/esp-fish-feeder

The main library uses the limit switch, buttons, and a buzzer and you'll need to setup ESP-IDF to use it.  Last tested in esp-idf 5.3.

Another option is this simple Arduino script that only controls the motor: 

https://github.com/ataboo/esp-fish-feeder/blob/master/Arduino/simple-fish-feeder/simple-fish-feeder.ino

Operation

1. Remove the base
2. Extend the buckets by hand
3. Flip over the base so the buckets are facing up
4. Fill the food for each day
5. Push the buckets in manually stopping short of the limit switch
6. Mount the feeder (ex. 2-way tape) so the buckets will dump into the tank as they extend
7. Make sure there's enough clearance for all the buckets to extend
8. Power the feeder and push the load button

1 bucket should extend each day at the configured time.

Update: I've just added a 10 bucket version and added configuration for steps per bucket.