Arduino soil moisture sensor

In this Tutorial i will show you how you can build a cheap and simple moisture sensor and read the data from the Arduino to your PC.

What you need:

Part 1: Moisture Sensor

Mix the plaster with water and fill the plastic tube with it. Let it dry a little bit and stick the nails in it. Let it try for about 2 hours, than remove the plastic tubing and then let them dry for 24h hours. You can read about the details here.

IMG_5828 IMG_5830

Part 2: Read from Arduino into PC

The circuit setup is pretty easy:

Screen Shot 2013-05-30 at 12.30.50
With the Analog In Port 0 we will observe how the electricity flows through the sensor through the resistor. If the sensor is dry there will be no electric flow.

This is all you need to get the sensor data from the Arduino.

The Arduino code to read the Analog0 Pin:

int analogPin = 0;
int val = 0;

void setup()
  Serial.begin(9600);          //  setup serial

void loop()
  delay(10000); // 10 Seconds delay
  val = analogRead(analogPin);    // read the analog pin
  Serial.println(val);             // write value to debug console

My test setup:

As an addition, i added an Ethernet shield to this which uploads the measurement data every hour to an PHP Script which shows it in a nice graph.


Self build Carbon-Filter

So, to eliminate all the smell the chilies could have i build a little carbon filter.

Two PC fans will suck the air out of an cuted plastic cup and create an vacuum. The air from the box will flow via the holes in the cups through the carbon and than out of the Fan.

You need:

  • Two plastic cups, one should fit into the other
  • activated carbon (you get it really cheap from amazon)
  • two pc fans (i used 80mm 12V)
  • sticky tape

Cut the two cups so that you can stick one with bottom last into the other one. Perforate both with many holes.

Stick the one without the cap into the orher one and attach the two pc fans (one fan on top of the other)

Fill with carbon and thats all!

Self build cupboard grow box – Part 2: construction

So, i build the Cupboard and here are some pictures of it. I used my Hydrobox and i will add a 30 Liter barrel to circulate the water to stabilize the ph-value. A post about that will follow.The cupboard, closed.

The electronic-shelf, with Co2 pump, Thermometer and a multi socket.

Magnet that holds the door of the “fake shelf”.

Every wall inside is covered with white foil.

The LED light and an self build Carbon-filter.

The backside with the electronic of the carbon-filter.

Temperature and humidity sensor.

The Hydrobox. On the bottom i sawed the floor of the cupboard to get a little more height.

All in action.

Hydrobox from the Top.


This should give you an basic overview, if you want to know more, don’t hesitate to ask.


Self build cupboard grow box – Part 1: preparation

Winter is boring so i decided to grow some hydroponic Chilies and build my own grow box.

To do that i need a few things:

  1.  a cupboard
    After some research i found a great cupboard on amazon its big enough for at least two Chilies and it has an extra shelf where i can put all the electronic stuff.
  2. some light
    Im not sure with what i am going here. My first thoughts where that i use fluorescent lamps but I’m not sure about the heat generation. I read much about LED lamps but i have no clue about them. So i have to research and i will post my research on an extra post.
  3. filter for the used air
    Some 12V PC Fans should do the job, maybe with an extra carbon filter to eliminate all the smell.
  4. a hydro box
    I think ill just use the one i build some posts before. 
  5. nutrients
    I already have them from “Advanced Hydroponics“.
  6. some extra stuff
    white foil for the internal space, thermo- and hydrometer


So i hope thats all i need, update with pictures and how i build all the things together will follow soon!

How To Build A Hydroponic Garden (DWC)

So, i build a small Aero-Hydro growbox, and here’s how:

You need:
– a Box
– a Air Pump (Like one in an aquarium)
– Net plant pots
– Black spray can (This is necessary because light will benefit algal vegetation)
– and some tools

1. Draw the points where the holes for the netpots will be

2. Drill the holes. If you dont have an driller like me saw it out. (First draw holes with a circle)

because my driller was to small, i had to rasp the holes a little bit wider

3. Sand the edges of the holes to make it  cleaner

4. Sand the hole surface of the box. The spray paint will hold better. Maybe use a finer sand paper, the one i used made big scratches

4. Stick an area with tape before spraying, so we have a window to see the water level

5. Spray. Look at the label of your spray can how to spray it

6. Get rid of the tape and get your pump with the pipes

7. Drill holes into the box for the pipes

8. Stick the pipes, i used a hot glue gun

9. Stick the ends of the pipes to the bottom underneath the holes

10. Enter the netpots and close the box.


 Thats it.

At beginning, the water-level should be about 1-2cm into the net-pots. When the plants grew some roots the level can also be lower.