Our entire project revolves around data processing of soil moisture, then subsequently using that data to efficiently and autonomously keep the soil hydrated. This is accomplished through use of a custom program created to be implemented using an Arduino board as a control system. Moisture sensors will read water content within various samples of soil, then relay this information to the Arduino to be interpreted. Once hydration levels fall below user defined levels set by the user within the program, the Arduino will send a signal to one of the various solenoid valves, utilized to regulate the flow of water to individual plants, and direct it to open up for a set period of time. With the addition of a centrifugal pump, water will be drawn from a source or reservoir of water and delivered to flow gating system. Once pressure has built up within this gating system, the flow of water is diverted by solenoid actuated valves where it then travels down a length of pipe to a shower head that will sprinkle water over the plant in need of hydration.
With the prototype built, we hope to validate the efficiency of a self-operating system. Minimal human interaction is one of the major goals of this project, along with an efficient way of watering which leads to conservation. These goals can be achieved through careful consideration and calculation along with utilizing relevant concepts learned throughout the curriculum of Mechanical engineering such as;
Putting knowledge of these principles to use has allowed us to more accurately gauge exactly what parts would work within the constraints of our concept. This incredibly important because, before we invest in the various components of our prototype, we need to be sure that they will be adequate to achieve all the specifications we have set.
Shurflow Nautilus Single Fixture Water Delivery Pump
Because of the head pressure requirements of our prototype, we calculated we would need a pump that could deliver around 10-15psi of pressure. This pump was chosen because it could achieve the pressure we needed while maintaining a relatively small form factor, and run on DC electricity. Furthermore the pump will easily be controlled by the solenoid valve.
Arduino Mega 2560
Many of our project partners have experience creating programs utilized by Arduino boards. These boards are versatile and many add-ons such as motors, sensors, and valves, are designed specifically for these boards by many different companies.
Foxnovo Waveshure Moisture Sensor
This particular moisture sensor was chosen because of its compatibility with the Arduino coupled with its low cost. It is made out of a metal that will not corrode in most soil types, and its sensitivity to various levels of soil moisture will allow us to receive more complete data.
Water Solenoid Valve 12VDC - 1/2
A 12V solenoid valve will be used to direct the flow of water. This particular valve has been designed specifically for the Arduino. The valve is cheap, costing only 7 dollars, and is available in a half inch size, which was determined to be perfect for our application.
The prototype drawings as designed using PTC Creo 3.0 are displayed below with appropriate captions in the drawing. These initial drawings were significantly modified as the project progressed with the greatest differences being in that very little solid piping was used. Most of the plumbing involved was constructed using flexible hoses. Overall, the final product was very similar.
After completing our prototype, a video was taken to record our progress. The first run was a success and can be viewed using the following:
Closed-Loop Irrigation Prototype
Narrated by Adin Fidahic and recorded by Emmanuel Sadek, as the prototype operates, the values recorded by the moisture sensor manipulate the two solenoid valves and control whether the pots are to receive water or not. Each solenoid-sensor system runs completely indepdently, as can be seen at the end of the video when the pump turns on and properly feeds only the right pot.
The following electrical schematic represents exactly how the Arduino Mega 2560 interfaces with the solenoid valves and moisture sensors to properly operate the system. It is a very typical wiring schematic that is reliant on the independent function of two relays which each correspond to their own solenoid valve and moisture sensor. Using a proper Arduino script, this system operates consistently while being entirely free of human interaction.