Using Raspberry Pi technology to remote monitor and control hydroponic systems

Students in the Ag Mechanics class at Wesclin High School began the design and construction of the hydroponics system in the 4th quarter of the 2021-2022 school year. They began by brainstorming ideas as to the initial design set up to reduce the amount of square footage required but still be efficient for harvest and water flow. After much deliberation and several proposals by students, a concurrence was made on a more vertical, A-frame type system utilizing metal framing struts with slots. This permitted the most flexibility in adjustments to the system to ensure that water flow rates could be adjusted based on the change in slope. Students then created a scale drawing utilizing AutoCAD to create a bill of materials. The metal struts, fasteners, and PVC pipe and fasteners were then purchased. Students in the Ag Metal Fabrication class did have to perform some welding at the top and base of the structure to create the initial A-frame supports. Ag mechanics students then calculated flow rates based on the diameters of the PVC pipes and water pump capacities to determine the ideal slope of the system to ensure the water was continuously flowing to limit sediment deposits but yet did not cycle the water too quickly. After testing, the frame and PVC components were then disassembled and moved into the greenhouse.

On May 16th, 5 students and the agriculture teacher (Taylor Zurliene), attended a farm tour as part of the "Summer Twilight Series" put on by the University of Illinois Extension. They visited Little River Farm in New Haven, IL to view his hydroponics setup where he utilizes wick, drip, and deep water culture (DWC) hydroponics systems to grow strawberries, tomatoes, and leafy greens for retail and wholesale. After learning about this farmer's system and sharing the information with students involved in the project that were unable to attend, it was decided to slightly modify the plan for our system. Originally, the plan was to only use a Nutrient Film Technique (NFT) system. Instead, the students decided that a more diverse system could be utilized. They wanted to use the reservoir for the NFT system as a DWC system as well. Combining the two has the advantage of better space utilization as well as the ability to grow crops that do well in DWC (such as lettuces and leafy greens) in that part of the system and crops that take longer or need more space (such as strawberries, tomatoes, and peppers) in the NFT system. The greatest issue foreseen with this is providing the precise fertilizer for each crop without limiting or exceeding the requirements of another crop. Nonetheless, this is a limitation that can be worked with. 

While the original plan was to get the system wired and running prior to the summer of 2022, the global shortage of computer chips hindered the group. Raspberry Pi systems are essentially a computer board in a case and they have been nearly impossible to purchase. Estimated lead times at different suppliers were anywhere from 6 months to 2 years. After signing up for "in stock alerts" from several suppliers, we were finally able to acquire 2 Raspberry Pis in December of 2022 and that part of the process can now begin with the current Ag Mechanics class and be completed prior to the summer of 2023. 

Initial tours have been provided to two administrators and three ag teachers to show the progress of the system as there are two nearby schools that have just erected greenhouses and are looking to increase their profitability within them. A student also lead a presentation with the local garden club on the design of the system. Parents also viewed our current plans and setup during our annual spring open house and plant sale that is held in the greenhouse.