Fish Tank Temperature Realtime Visualiser


Introduction: Fish Tank Temperature Realtime Visualiser

About: Hacker, maker and fixer on electrical, electronic and woodworking projects.

Hello Instructables!

I always wanted to have a way to easily check the temperature of the water in my fish tank.

Using 2-3 LEDs for low/normal/high temperature seems too dull to me so I decided to use an RGB LED strip with a waterproof temperature sensor (No the LEDs will not be inside the water. Their light will not reach my fish - I love them too much to treat them like that)

Check here for source code and more comments:

Step 1: Project Parts

For the project you will need:

  • 1 x Linkit ONE
  • 1 x RGB LED Strip as long as you need
  • 3 x MOSFET (IRLZ44N)
  • 3 x 10kΩ 1/4W resistors
  • 1 x waterproof DS18B20
  • 1 x 4.7kΩ 1/4W resistor
  • 12V power supply - its power depends on the length of the LED strip - please calculate in advance
  • Linkit ONE battery or a 12V to 5V buck down converter - a USB car charger is fine

Step 2: Wiring

Follow the attached fritzing file.

Please mind that because RGB already needs red colour for the RED channel the +12V line is represented with black. Once all wiring is completed, seal Linkit as spills are a very effective way to kill your board.

Step 3: Load the Code

Load the attached code. Please mind that for demo purposes the temperature range is extended to something easier to demonstrate. Please adjust to your fish tank type (usually 25-27°C).

Power up your project and enjoy!



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    Please describe your wiring and what components you are using. Additionally please attach your code (please do not copy-paste it here as its hard to read - simply attach the .ino file)

    Can you show us a diagram of how you connected the DS18B20 to the breadboard?

    6 replies

    You mean apart from the diagram on step 2 ?

    The part with the temperature sensor. i have all the wiring done. except for the sensor.

    What colours does your waterproof DS18B20 cables have? If they are red, black and white, see diagram from Step 2 and connect red to red, black to black and white to orange. Is that clear?

    Those are the colors i have but i dont see the diagram. i did all the other wiring.

    On the attached diagram (Fritzing sketch) you see a transistor at the bottom with 3 legs. They connect to a black (top) an orange (middle) and a red wire (bottom). Connect your red to red, your black to black and your white to orange. Hope that helps


    The thing that goes in the water. How do i connect that

    Hi, I was just wondering what is wrong with exposing fish to led lighting? I have never heard anything like that before.

    1 reply

    to LED light is not something bad. Its the changing of the
    colour/intensity that may affect them. DS18B20 is not the most
    accurate sensor (I think +/-1'C) and there are cases where it may
    jump from one colour to the other until it decides. I have separate
    lights for inside the tank ;)