I am a high school student preparing for university entrance exams. As this is the final year of school, I put extra effort into preparing myself for university entrance exam. Therefore, it led me to an idea for a project to help minimize time in doing my everyday life chores. I built an automatic fish food dispenser to help me feed the fish while I concentrate on my study.

I built a simple automatic fish feeder from servo that I already have at home and container made from the corrugated plastic sheet, it's easy-to-find material, can keeps food prevented from moisture and water, moreover easy to install at tank. If you want to store more food, you can increase the size of container.

This simple automatic fish feeder can be use with any type of food and easy to manage. The code written here is suitable for number of fish I have, you can adjust speed and angle of servo as you like. This code will automate feed every 8 hours - Morning, afternoon and night.

The Absolute Time Anchor (DS3231)

An Arduino Nano's internal clock drifts over time. Over a week, it might lose 15 minutes! To feed an animal, the time must be perfect. You must use the DS3231 I2C RTC Module. This chip contains an internal crystal oscillator that compensates for temperature changes, guaranteeing absolute precision over years!

You structure the C++ code to use the TimeAlarms architecture.

Alarm.alarmRepeat(8, 30, 0, MorningFeeding);  // 8:30:00 AM every single day
Alarm.alarmRepeat(17, 0, 0, DinnerFeeding);   // 5:00:00 PM every single day

Inside the loop(), you just call Alarm.delay(10);, which forces the Arduino to constantly check the atomic clock to see if it's currently feeding time!

The Archimedes Auger (Servo PWM)

A standard trap-door feeder clogs instantly with damp fish flakes. The Best Design is to utilize a 3D-printed Archimedes Auger (a spiral screw inside a tube, exactly like industrial grain silos!).

A Continuous Rotation Servo (FS90R) is bolted to the back of the auger. This type of servo doesn't turn 180-degrees and stop; it spins infinitely like a motor, but is perfectly controlled via PWM. At the scheduled time, the feeding function fires: The FS90R servo perfectly executes a set number of complete rotations, dropping a perfectly portioned amount of fish food into the tank water below, then rigidly locks in place.

Aquatic Automation Setup

• Arduino Nano (The ideal tiny form factor).
• DS3231 I2C Real Time Clock Module.
• FS90R Continuous Rotation Micro Servo (Do NOT buy a standard 180-degree SG90, it will shatter the auger!).
• A 3D-Printer to fabricate the custom, watertight auger and food hopper funnel.

Good luck. See you in the next project.