2. Methods

2. Methods
2.1 Equipment
The equipment that we are going to use are as follows:
1) 1 X Arduino
In this project the Arduino is used for the controlling of the Automatic Plant Watering System. This is a board which is very useful as it can help us act as the main controller for this project. This device is very easy to operate, but needs the knowledge of coding.

3) 1X Soil Humidity Sensor
The soil humidity sensor is onething that we are going to make ourselves, basically by two screws and a piece of Styrofoam.

4) 0.5M Wires
This is to connect the humidity sensor to the breadboard, eventually leading to the Arduino ANALOG 0

5) 1X Electrical Power
This is basically what we need for the whole system to be powered.

11) 1X LCD Display
This is a Liquid Crystal Display system where it is being connected to the system. The LCD would show the status of the plant, where in this case, if the soil is too wet or dry.

2.2 Diagrams

2.3 Procedures
2.3.1 First Phase ­ introduction to Arduino
For this first phase of the project we would be setting up the Arduino Board, along with the Liquid Crystal Display
Firstly, we would get all the items assembled on one table. For the first part of this project, the items are:
­ 16 pin Liquid Crystal Display
­ Arduino Board

­ Jumper Cables
­ Multicore Cables
­ Bread board for first build of simple components.
­ 2 Long screws
­ 10cm X 10cm piece of Styrofoam.
­ 10000 Ohm Resistor
­ Potentiometer
Firstly, to experiment with the Arduino board, as this is the first time we are doing something related to the Arduino system. As we are provided with a Sparkfun Inventor’s Kit (SIK), we are now going to use some jumper cables from the SIK kit, Liquid Crystal Display and a breadboard. Firstly, we would solder pins onto the Liquid Crystal Display, which actually secures the pin onto the Liquid Crystal Display. The Liquid Crystal Display, along with the pins, would then be inserted into the far end of the breadboard.

Now, we would connect the Ground from the Arduino board into the breadboard which in this case, the picture below illustrates a black cable. After we have connected Ground to the breadboard, we would have to actually also put in the life cable, which in this case we are going to insert a red jumper cable into the 5V output on the Arduino board to the breadboard. This cable is also illustrated in the picture below, along with the black jumper cable. There would also be another black and red cable connected from the power section of the breadboard to the breadboard connected to the Liquid Crystal Display.
After we have attached both the cables, we should connect the Arduino board to a power source to either a power socket or even a computer, which in this case, we are going to use our MacBook for the power supply and coding for this project. So, after we have hooked up the cable onto the computer, we should see the Liquid Crystal Display light up.
After we see that the liquid Crystal has lighted up, it shows that we have successfully completed the lightning portion of connecting the LCD display.
Now, we are going to move on to the connection of the power to activate the display dots on the system. We would have to also adjust the contrast of the Liquid Crystal Display, so for now, would need to connect a potentiometer to the breadboard then to the Liquid Crystal Display itself. The 16 pins are : Vss, Vcc, V0, RS, R/W, E, DB0, DB1, DB2, DB3, DB4, DB5, DB6, DB7, LED+ and LED­­.
We would first connect the Ground cable to the right of the potentiometer, before connecting the 5V red cable to the left of the potentiometer. As we need to adjust the contrast of the dots on the Liquid Crystal Display, we need to also connect a jumper cable from the central outlet of the potentiometer to the V0 port of the Liquid Crystal Display, as shown in the figure below. 
After we connect these cables, we should see both the lights and the dots on the display be filled up.
Though we can see that we have actually connected the display and it lights up, we still cannot control the LCD system as we have not connected the control wires onto the Arduino board. These wirings are meant to be controlled via coding with the application which came with the Arduino boards, to input how the user wants the LCD to work.
2.3.2. Phase 2 ­ Setting up Liquid Crystal Display to work with Arduino with Text.
To have control over the whole LCD screen, we then need to connect several jumper cables
from the digital output of the Arduino board to various pins of the LCD screen. The pins are:
  • ­  D4 to Digital Port 5
  • ­  D5 to Digital Port 4
  • ­  D6 to Digital Port 3
  • ­  D7 to Digital Port 2
  • ­  R/W to Digital Port 12
  • ­  E to Digital Port 11
    Thus the diagram of the completed and connected LCD to the Arduino Board is listed below. 
But that is not all, to also gain total control, we need to program in the codes for the LCD to display. You can display a lot of information on the displays, but first, we would go with this LCD test. 
Now, we should be able to see the LCD display whatever we want right now. A sample of what we did is shown in the figure below.
For this project, we would not be using a conventional soil moisture device. Instead we would build our homemade and simple soil moisture sensor, basically basing of measuring the value of the resistance of the soil. If the soil is wet, there would definitely be less resistance as there would be a lot of conductivity for the soil. On the other hand, the soil which is dryer would definitely have more resistance as there is less conductivity in the soil. Based on these theories, we are going to operate a simple but very important and useful sensor.
2.3.3. Phase 3 ­ Setting up main sensor
To set up the moisture sensor, we need to use the two screwdrivers, the 2 multi core wire which is 0.5m long each and 2 jumper cables. First we would actually solder the each of the multi core wire to each of the jumper cables, before using heat string to wrap the soldered portion up, as they were exposed, to prevent any risk of electrocution happening to any of us.
After we had soldered the multi core wires to the jumper cables, we would need to also solder the two screws each to each of the other end of the multi core cables. As the multi core cables would not be exposed, we would need to use a wire stripper to expose the multi core wire. After exposing the wire, we must wrap the exposed wire around the two nails each, before soldering them. After that, then would we need to attach them into holes which would be found in the piece of Styrofoam. This was drafted out as to keep a distance in between the two screws constant to make them have the most accurate readings over the longest period of time. However, though there were very little was that we can use to measure soil moisture, the nails actually use electricity to keep track of the moisture by using resistance of the soil. 
For the Arduino board to actually sense the resistance between the two screws, we had jumper cables to connect the screws to the Ground, Analog and 5V ports of the Arduino board. This would create a complete circuit, where the Analog 0 is used for taking down the resistance of the electrical energy between the two screws. This is also illustrated in the figure below. (Fig7)
After we have completed all these steps, the last step that we are going to do is to code what we want the Arduino system to record down and display on the Liquid Crystal Display. Firstly we would state down the ports needed for the Display and the Analog ports needed for our homemade soil sensor system.
2.4 Risk Assessment and Management
Risks: Risk of having electric shocks due to contact with socket with WET human hands. Precautions: Dry hands before handling any electronic equipment.
Risks: Risk of having injuries of handling sharp equipment due to improper handling. Precautions: A MUST to adhere to the safety systems of the lab, for example in this case, the safety of the equipment handling in the lab, like to ensure that for instance the penknife is used the proper to minimize the injury as much as possible.
The handling of knives is closely monitored to make sure everyone is safe at using knives.
2.5 Data Analysis
Firstly, the wetness of the soil would be measured using a humidity sensor connected to the Arduino system. When the Soil is too dry, the sensor would transmit the information back into the device and trigger an alarm to signify that the plant is dry. As this is an engineering project,

we need to prove that the system actually works, so we actually need to monitor the situation of this automatic plant watering system. To monitor the automatic plant watering system, we need to have a 24/7 monitoring system. This could include the CCTV surveillance cameras that are used in the school. We chose this system because we need to keep track if the plant is working properly, so that we could make any adjustments if possible.
2.6 Calibration
For the calibration of the moisture sensor, we would need to test out the high and low of the moisture sensor. For example, we are going to add 100ml of water to a 100gm of soil and to add 0ml of water to 100gm of soil.
2.7 Analysis of Results
To have the analysis of the results, we would need to plot graphs to shown that the product works. As a start, to actually show that the resistance of the soil is relevant to the soil moisture, we did these steps:
  1. To have a beaker of dry soil provided
  2. To add a certain amount of water into the beaker of dry soil.
  3. Measure the resistance.
  4. Calculate the amount of water added by the resistance ONLY
  5. Plot a graph of calculated water VS Added water. 

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