• hmxmghl Created Project

    10/02/2016 | 1:15pm

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About This Project

In this project, you will learn how to make an intelligent aquarium. There are times when you have to go out on a trip for a few days, and have to worry about who will take care of the fish. This is system will rid you of your worries. It will auto feed, and display the acidity of water on an LCD screen. I have tried to keep this project as simple as possible, and hopefully you benefit from it!
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Project Info


  • Arduino
  • Hardware
  • Overall

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  • hmxmghl
    • User:hmxmghl
    • Rank:Journeyman
    • Projects:10
    • Joined:2016

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.How is this going to work ?

I thought it would be best if I describe at the start of project how this system is going to behave. A stepper motor will be attached to some container ( I used Soft Drink Tin Pack), which will contain the fish food. When it is time to feed the fish the stepper motor will rotate a few steps, which will allow some food to drop into the aquarium. After a set amount of time the stepper motor will rotate closed again. Secondly, a probe will be inserted into the aquarium which will be attached to a EZO pH circuit, which will determine the pH of water as well as display it on an LCD. I tried to keep it as simple as possible and I hope you find it easy too. Lets get started.

.What are we going to use ?

This section is dedicated towards shedding light on the parts being used.

.1. Stepper Motor (28BYJ-48):

The Stepper Motor is a motor controlled by a series of electromagnetic coils. The center shaft has a series of magnets mounted on it, and the coils surrounding the shaft are alternately given current, creating magnetic fields which repulse or attract the magnets on the shaft, causing the motor to rotate. This design allows for very precious control of the motor. There are two basic types of stepper motors, unipolar steppers and bipolar steppers . 28BYJ-48, a very good and extremely reasonably priced stepper motor easily available in market. I used it in many of my projects.

.2. EZO pH Circuit:

This is a pH sensor module which will be used to determine the pH of water. pH normally tells how acidic or basic water is. If water in an aquarium is left for few days without being changed or treated, it will become contaminated and acidic.

.3. BNC Connector:

This will be used to connect the probe with the pH sensor.

.4. pH probe:

One end of the probe will be inserted in the water tank (aquarium) and other end will be connected to the BNC connector, which is connected to the pH sensor module.

.5. 16x2 LCD:

After determining the pH of the water, we will need to display the value on an LCD. I am using this 16x2 LCD to display the sensor value.

.Making Feed Container

In this section I will be focusing on making the feeding container. I have used Soft Drink Tin Pack to accomplish the goal. First of all, holes are drilled at the upper part of the Tin Pack to attach the stepper motor. The image below shows the container with drilled holes. Then the Stepper Motor is attached using those drilled holes. Following the pictures below you should be able to find the appropriate tools, as well as to add the stepper motor to the feeding container.

I used the 2mm drill bit shown below to drill holes in soda can:

I used the cutter shown below to cut a place in the can to place the stepper motor. I also used this cutter to make the cap:

I used these 1 inch long screw and nuts to hold the stepper motor in place.

This screw driver was used to tighten the screws:

I used a couple of NR bottle caps shown in the image below to make the 'gate' for the food:

This is how feed container looks after doing all this:

.Making a Cap for Container

First of all, take a NR bottle cap and flatten it using a hammer as shown in images below:

Then cut it from the edges using a cutter shown in image above and form a shape like this:

Then take another NR bottle cap. Also flattening it using hammer. Cut it using a cutter and form a shape like this:

Then place it over the other cap and it will look like this:

Then use any adhesive glue that can hold steel together to join these shapes:

Now the cap is ready. I used the 'Depoxy Magic' shown in image below as an adhesive but you can use something else that you think is better:


I will show the connections in separate pictures to avoid clutter:

.1. Stepper Motor with Arduino

.2. LCD with Arduino

.3. pH sensor with Arduino


In this section, I will be focusing on programming the Arduino. The arduino will be programmed so it will operate the stepper motor, as well as get data from the pH sensor and display it on the LCD screen. Below you will find the code needed to operate the arduino. Since every aquarium is different I thought it would be best to comment the code where you can customize it. The code is very easy to understand after reading the comments, and you should have no problem simply editing a few values to match your tank. It is also important for you to modify the code due to having a different feeding container.


Updated 10/15/2016 by hmxmghl

.Testing our work

Below is a video of the finished product running. You can see the pH value on the LCD, as well as the stepper motor operating(opening and closing the gate). You can modify the timing of opening and closing of the gate in code as per your aquarium's need. Thank you for watching.

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Last updated on 10/15/2016

by hmxmghl

370 129b
Qty   Item Where to Find Est. Cost More Info
1 Arduino Uno

Arduino Uno

$16.06 3 links  
1 28BYJ-48 Stepper Motor Item Number: 28BYJ-48

28BYJ-48 Stepper Motor

Item #: 28BYJ-48

1 EZO pH circuit Item Number: 1

EZO pH circuit

Item #: 1

1 BNC connector Item Number: 1

BNC connector

Item #: 1

1 pH probe Item Number: 1

pH probe

Item #: 1

$72 1 link  
1 16x2 LCD

16x2 LCD

1 M/M Jumper Wires

M/M Jumper Wires

1 ULN2003A Motor Driver Item Number: ULN2003A

ULN2003A Motor Driver

Item #: ULN2003A

$2.68 1 link  
1 Variable resistor Item Number: Potentiometer

Variable resistor

Item #: Potentiometer

$7.26 1 link  
1 2mm Drill Bit Item Number: 2mm Drill Bit

2mm Drill Bit

Item #: 2mm Drill Bit

1 5k Ohm Potentiometer

5k Ohm Potentiometer

1 Screw and  nuts

Screw and nuts

Assortment of different s