Table-Top Electric Plant

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Introduction: Table-Top Electric Plant

About: I'm a highschooler who is interested in technology, science, and engineering. In my spare time I work on projects that allow me to learn new skills and concepts.

Plant watering can sometimes be a pain... Here's a solution that automatically waters plants depending on the moisture of the soil, no timers required!

It works like this: when there is water in the reservoir and there is no water in the soil, the pump turns on, which transfers water from the reservoir to the plant.

This design is just a scale model, but the circuit it fully functional and can be used to water larger plants!

Step 1: Materials

Here's what you will need to build the electronic part of your watering system:

  • 5v power supply (from USB charger)
  • 1 NPN transistor (S9014)
  • 1 PNP transistor (S9015)
  • 2x 100k ohm resistors
  • 1k ohm resistor
  • 47 ohm resistor
  • Stripboard or perfboard
  • Diode
  • N-Channel MOSFET (SW2N60)
  • 2 LEDs
  • Aluminum Foil
  • 4 binder clips (or paper clips)
  • 1’ of tubing for pump
  • Wire
  • Switch (optional)
  • 5v submersible water pump

Some of these parts (like the water pump) were bought from eBay, while everything else I had lying around.

I also needed two glasses and some plywood to house the plants.

Step 2: Building the Circuit

Start by soldering the components onto the perfboard (or stripboard) according to the circuit diagram above. Be sure to connect extra wiring to the motor, sensor leads, and switch (if you use one).

I then used those mounting holes to secure the board to a piece of wood, this piece of wood will later be screwed onto the base of project.

The wires that went to the motor (or pump) were soldered on as well, and some heat shrink tubing was used to protect them.

Step 3: Building and Connecting the Sensor Electrodes

I used aluminum foil for the senor electrodes because aluminum oxide (the stuff that forms when aluminum is exposed to moisture) does not flake off (unlike rust).

These 1" strips of aluminum foil were bent with an inch overhang, then they were glued into the cups using spray adhesive, about 5mm away from each other.

I also tried steel and galvanized steel for electrodes with poor(er) results.

The electrodes were connected to the circuit by attaching the wires (coming from the circuit) to the foil using binder clips.

For the reservoir electrodes, be sure to leave some space between the electrodes and the bottom of the cup. This is so the motor properly stops before all of the water is depleted.

Step 4: Transferring the Plant(s) and Connecting Tubes

At this point I transferred some grass from the garden to the plant cup. I also attached a tube to the outlet of the pump and dropped it into the (now full of water) reservoir.

To secure the other end of the tube in the soil I used a small wooden dowel which I stuck to the very bottom of the cup.

Step 5: Making a Base and Securing the Cups

I felt like a base was missing, so I cut out a 10 by 4" piece of plywood and used some double sided tape to attach the cups on.

The circuit board was also attached with some screws.

Step 6: Extras!

I set the entire system up on my window sill and recorded the average height of the grass over 7 days. It grew quite fast, and at the end of the 7 days, the water was almost gone.

I suggest adding a bit of water-soluble fertilizer to speed up growth.

So, that's how to make your own plant watering system! Feel free to modify this design to fit your needs (like watering an actual plant!).

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    39 Discussions

    Is the NPN transistor upside down? I can't see a condition where the transistor would conduct.

    0
    AidanK18
    AidanK18

    Reply 1 year ago

    It is. See HBSkirmit's comment.

    0
    AidanK18
    AidanK18

    Question 1 year ago on Step 2

    Which board did you use and where might I be able to get one?

    0
    DarshanC6
    DarshanC6

    4 years ago

    hey what is the name of the diode ?

    0
    tinu k cheriya
    tinu k cheriya

    Reply 2 years ago

    Yes I also have the same question

    0
    tinu k cheriya
    tinu k cheriya

    Question 2 years ago

    Sir what value of diode you used

    0
    mariamaldabas
    mariamaldabas

    Question 2 years ago on Step 1

    how can i find the materials to make thing i live in dubai

    0
    GirlieZ
    GirlieZ

    3 years ago

    Hi! What value of diode did you use and how many?

    0
    harman12
    harman12

    5 years ago

    R u use any soil sensor in this project

    1
    sami suliman
    sami suliman

    5 years ago on Introduction

    hi, thank you so much its really great idea

    could you please make diagram using fritzing program >>>>because

    I don’t have much background about electronic

    please I need it soon as possible

    thanks man

    0
    Mohamed Youssry
    Mohamed Youssry

    5 years ago

    Nice but in egypt can't find water pump take 5v it,s just 220

    0
    comsa42
    comsa42

    Reply 5 years ago

    Well that's why the circuit is powered with a 5v DC supply. Any USB phone or tablet charger that accepts 220v AC will work.

    0
    mohd.habib.98

    is it okay to use 12V water pump the one used for the car glass washer ?

    0
    twobadrobots
    twobadrobots

    5 years ago on Introduction

    Two tracks/traces of a stripboard make better moisture probes instead of foil.

    1
    tisaconundrum
    tisaconundrum

    Reply 5 years ago on Introduction

    but stripboard gets all green and starts to fail overtime.