Introduction
I am happy to present my final project for Introduction to Mechanical Engineering: Programming and Hardware Interface (MEGN200). It was a fantastic project experience, I'm looking forward to carrying this project on, and to all projects in the future. This project gave me the opportunity to bridge the gap between hardware and software, giving me critical insights into real world project design, and validation and verification. As well as experience working in a small team, communications, document sharing, and idea collaboration.
Demonstration
System Hardware
Above on the left is the motor used to move the water from the tank at the bottom of the pot to the plant at the top of the pot. The image in the middle shows the sensors used to dictate when the plant should be watered. The two-pronged sensor monitors the moisture of the soil, and the second sensor monitors the ambient temperature and humidity. Lastly, in the image on the left a digital display shows the outputs of those sensors.
Sensor Functionality
Moisture Sensor: Uses a circuit to detect changes in capacitance caused by varying moisture levels. By probing the charge of the soil, the sensor calculates the moisture level and outputs volumetric water content, which is a ratio of water volume to total volume. Ranging from 1 (completely submerged) to 667 (completely dry).
Temperature/Humidity Sensor: Uses a capacitive humidity sensor, which absorbs water vapor and changes the dielectric constant of the sensor, the effective capacitance changes and recalculates relative humidity as a percentage. As well as a thermistor, which is a resistor that changes with temperature, it then calculates and outputs the temperature based on that resistance.
Digital Display: Is a simple LCD Display, which cycles though temperature, humidity, and soil volumetric water content in 5 second intervals.