Ivan De Padua

Smart systems are something I've always been interested in. For my final project, I wanted to incorporate a hobby that I enjoy with embedded systems which has led me to design and build an automated greenhouse monitoring system. The experience of working in this project was fun and simultaneously hard working but new skills and knowledge was gained throughout the project.

University of Derby is a fantastic university with amazing opportunities. They have excellent facilities for engineering courses. The lecturers are well experienced in their fields and the career services are organised and very helpful which helps students succeed in their desired field.

Design and Build of an Automated Greenhouse Monitoring System

Introduction

The worlds largest greenhouse, The Eden Project, can be found in Cornwall, England. According to Halifax Courier (2020), in the UK, gardening is becoming more than a hobby. Many people now live in a flat or house that has no garden. Having an Automated Greenhouse does not require a large space and a garden or yard to plant. A small space indoor is needed and the rest is handled by the system. The rise of technology infused smart or automated greenhouse is one of the major parts of recent transformation in the greenhouse industry. This offers new levels of technology and control to further optimise the growing conditions.

Aims and objectives

• To design and build an automated greenhouse monitoring system that controls and monitors the temperature, humidity, soil moisture and light sensitivity
• To autonomously active the actuators from the collected data from the sensors to control the growing environment of the plants
• To display the data collected from the sensors onto the LCD

System block diagram and circuit schematic

The system block diagram is the system design to meet the aims and objectives of the Automated Greenhouse Monitoring System. The microcontroller system requires a 12V power supply and a 5V voltage regulator for the PIC18F25K22. Also, 4 analogue to digital conversion, 2 digital inputs, 9 digital outputs, and I2C communication for the LCD Screen. The system also provides a 3.3V power supply for any Universal Synchronous/Asynchronous Receiver/Transmitter addition.

Design, build and programming

The Automated Greenhouse Monitoring System consist of 3 parts, the miniature greenhouse, the control/monitoring box and the water tank for the irrigation system. The water tank has 3 water pumps, the top of the water has the buzzer/alarm and the ultrasonic sensor used to monitor the water level. It can be conducted that after the 3 day investigation that it is possible to grow plants indoor using an automated greenhouse. It does not require human attention as much as having a normal greenhouse. It can be seen that the greenhouse promotes plant growth and has provided the plants great living conditions from days 1 to 3. The external body of the monitoring box has the in-circuit debugger for programming, power switch, a DC jack for the 12V power supply, 6 connections for the sensors, 7 connections for the actuators. The 20x4 LCD screen which displays the programmed start up message and then shows the live data collected from sensors and the water tank level. The system was programmed using MPLABX IDE.

Results and discussion

The tests for sensors and actuators were investigated for 3 days to test the functionality, accuracy and its reliability to maintain growing conditions for the plants. Each plant grows different depending on its size and the greenhouse was placed where daylight is available. The results were taken every hour for 3 days in order to get an accurate result. Temperature and humidity graph suggest that the greenhouse has consistently maintained the temperature and humidity. The average temperature on Day 1 was 23.3°C, Day 2 was 23.9 °C and Day 3 was 24°C. The function of the soil moisture sensors has successfully worked, as it shows in the graph that the moisture level of the plants at the beginning of the investigation was dry therefore the water pump was activated when the soil moisture sensor placed in the plants. Day 1 shows that the water level was between 20% to 30% which means that the plants had been watered recently and are wet. Days 2 and 3, the soil moisture content has remained constant. The results for the light sensitivity show that during the hours between 7:00 to 19:00 during the 3 days investigation, the resistance was low and the hours between 19:00 to 7:00 the resistance was high. It can be proven using the results that the LED grow light was on during the night and provided the plants 24hr period to grow. All results also proves that the programming of the sensors and actuators had successfully worked and provided a controlled environment for the plants.

Conclusion and further development

The project has proven that an Automated Greenhouse Monitoring System can be designed and built using a PIC Microcontroller PIC18F25K22 as the controller, analog sensors, actuators and an LCD Screen. A working prototype has been developed and produced to meet the aims and objectives of the project. The future of the automated greenhouse are unlimited with the technology advancing there are many innovations that can be interfaced. A heating option can be used if the greenhouse would be used for outside to accommodate the outdoor environment and weather. A sleep mode can also be programmed into the automation, when the system is not in use it can be set in sleep mode, and the use of interrupts would be introduced when it needs to update the data. Also, Wi-Fi modules and Bluetooth can also be interfaced.

Download Ivan's project overview poster (PDF) (this pdf document is not fully accessible but the contents within it can be viewed via the content on this page)