Automated Plant Watering

The Design Challenge

After doing some research on valid topics that interested me, I decided to engineer an automatic plant watering/irrigation system. I intend on tackling this project step by step in order to keep it organized and simple.

Summary of Research

General Research

  • Electricity: In order to best understand what I was doing while building my circuit, I decided to educate myself on a few basic concepts of electricity. First, I learnt about Ohm’s law, which can be summarized into the formula Voltage = I(Current)Resistance. Next, I researched different components to a circuit in which I learned about relays, sensors, microcontrollers etc.
  • Fluid dynamics and hydrodynamics: I also researched about fluids and how to best optimize the pipes in my circuit in terms of efficiency and practicality. I learned that the flow in closed pipes is driven by pressure. In order to calculate the flowrate, I looked into Poiseuille’s law. Poiseuille’s law can determine the volumetric flow rate of liquids using the liquid’s viscosity, the pressure difference in the pipe and the diameter of the pipe. This can be useful in determining the efficiency of my circuit and optimize it to provide the right amount of water in the right amounts.
  • Similar projects: To get some ideas for my prototypes, I researched what other people were doing in this field of engineering and how I could implement ideas from various other projects to mine. For example, I learned about drip irrigation and timed systems which don’t require moisture sensors.

Schematic And Design Of System

  • Use Arduino Uno as the microcontroller to process the data and control pump. Can also possibly use a raspberry pi with scratch on it or python.
  • Use a low volt water pump to control the water flow to the plant.
  • Get an LED display to show the percentage of the moisture present.
  • Do an experiment with all the different percentages of moisture to find the threshold value that the system needs for it to dispense water into the plant.
  • In order to get water fill storage with water and attach a tube with a pump to it.
  • Then make a compact system that can be duplicated for different plants or get one big system for the greenhouse.

The Program Of System

  • If using Arduino then code in C by looking at tutorials. If using raspberry pi then code in python.
  • Declare Moisture Sensor as Input and Pump as output.
  • Simple Program:

Materials Required

  • Arduino Uno/Raspberry Pi 
  • Soil Moisture Sensor
  • Relay module 
  • 12V 0.5A dc power supply (with stripped cables)
  • 5V USB power supply
  • 12V water pump
  • Breadboard
  • Cables
  • Plastic pipes and water bottle

My first step in this project is to create a very basic prototype with simple devices and basic programming to create a  project that can work effectively to water plants with respect to the moisture present.
My next step in the project is to finish up the prototype, create a more complex design which is aesthetically pleasing, it works on low power, it’s convenient to the average user and last but not least it can run 24/7.
Finally, my last big step would be to modify my finished prototype to be suitable for use in advanced greenhouse facilities such as the ISK greenhouse. 
I expect this to be done by the end of the academic year and I expect to have created an automatic plant irrigation and watering system that runs 24/7, its easy to use and it provides the right amounts of water to the plants.

Link to Process Journal & Final Reflection Video

Automating Plant Watering Through The Use of Sensors

Link to design journal