Simple aquaristic controller

Language: English / Polski

This project is a simple prototype of Aquaristic controller that supports automatic water change and automatic water addition from addional water tank.

Main goals of this project:

• automatic water change basing on data coming from sensors
• half-automatic water change "add/remove"
• automatic water addition
• automatic water addition tank refill
• feeding mode
• operating accessories in the aquarium

What will you need?

• basic knowledge about electrics and electronics
• soldering station
• knowledge about making a wires
• working 3D printer

Gallery

Front:

Side:

Back:

Inside:

Hydraulics and pumps

Requied hardware

• Arduino Due board
• LCD 2004 screen with HD44780 I2C converter
• DS1302 RTC clock
• analog joystick like KY-023
• SSR relay module
• automatic water addition pump (from washer for example)
• four servovalves with close detection

Servovalves

Why not solenoid valves?

Solenoid valves require pressure to operate. When removing water from the aquarium using mainly gravity we do not have enough pressure, so the use of solenoid valves falls off. In addition, we use one hose here to inflow and outflow water from the aquarium.

My own servovalves design

I have created my own servovalve design cheaper than servovalves from store. 3D printing knowledge is required to build them. If you want to use another servovalves project you need to make a fork of this project and implement your own interface from include/control/valves/valveModule.hpp.

Read more about servovalves here.

Water level sensors

What can you use?

You can use what sensor you want. The only one requirement is to conduct mass to arduino pin when sensor detect water.

I know from experience that loose copper bare wires as the electrodes of the water level sensor is not an ideal idea. Unless the water level sensor is galvanically separated from power sources just like industrial versions do.

What am I using?

I use float sensors in my design, because they are simple, cheap and effective.

Read more about water level sensors here.

The relays

Why not mechanical relays?

Mechanical relays failed in my case. In yours probably will not work too, and that's all due to electromagnetic interferences that occurs when switching. Partly it is the fault of the coils themselves, partly it's the fault of the mechanical relays do not switch at zero.

And Arduino is in no way protected against interference.

Why SSR relays?

SSR relays have such an advantage over mechanical relays, that they do not create electromagnetic interference. They are also more durable. They have more energy losses, but for me it doesn't make much difference.

Whose SSR relays?

It all depends on how power-hungry devices you connect. The heater will probably be the most resource-consuming device. I used an 8 channel SSR relay with G3MB-202P OMRON modules. However, the maximum load capacity of these relays is only two amps. So I had to buy a separate SSR relay FOTEK SSR-40 DA 40A DC-AC, because my heater was too big for small OMRONs.

You may also need one more relay.

Remember that SSR modules intended for AC will not be operate on DC current! Switching at zero blocks the whole relay, since the DC current is direct current and there is no zero, until you turn off the power.

So depending on the project you may need a separate relay for LED strips.

Read more about relays here.

How system works?

The system consists of 11 non-blocking modules. Each module manages only its own part of the system. For example: the aerationControl module only deals with aeration management and the lightControl module takes care of only aquarium lighting.

Each module has its own dependencies injected by the constructor.

And why manual injection? Because I did not think that C++ might have working dependency injection system and I do not like to create global variables.

Read more about system here.

Configuration

Configuration files are located here:

• screen: include/control/screen/lcd.hpp
• RTC clock: include/control/rtc/configuration.hpp
• relays: include/control/relayModule/devices.hpp
• water level sensors: include/control/waterLevelSensor/devices.hpp
• servovalves: include/control/valves/devices.hpp
• system modules: include/modules/Modules.hpp

Installation

To upload this project you need the latest PlatformIO IDE. Then connect the Arduino with a USB cable to the computer and upload the project to the controller.

First run

After the first start you need to check whether everything has been connected properly.

RTC clock

First make sure the RTC clock is connected correctly. To do this, go to Main menu -> Settings -> Time and day cycle -> Current time and set the current time. Then disconnect the controller completely from power and after a short while connect it on again. If time has been preserved, we know that the RTC clock has been connected correctly.

Service mode

Then make sure to connect sensors, devices and servo valves. To activate the service mode, enter Main menu -> Settings -> Service mode. Then our eyes will see three main categories.

• Sensors: this category is for checking correctness of connecting water level sensors.
• Devices: this category is used testing the correctness of connecting relays, wiring and the order of connecting the devices themselves.
• Valves: possibility to test servo valves. We have five options here:
  • Aquarium: servo valve connected to main water circulation and filtering system in the aquarium
  • Refill: refill tank servo valve
  • Clean water: servo valve connected to the source of clean water from a tap or water pipe
  • Sewage water: servo valve for water outlet from aquarium
  • Remote valves: shows whether remote connection with servo valves is connected.