ECE 110/120 Honors Lab Section : Plant Monitor

Statement of Purpose

A small houseplant pot that monitors soil moisture, sunlight, temperature, and humidity and uses that information to automatically add water and provide health alerts. The primary goal is to create a self-contained plant monitoring system that keeps the plant hydrated and alerts the owner if conditions potentially damaging to the plant's health are detected. This project should save the user time and headspace and assist those cursed with brown thumbs in keeping care of the plant. 

Background Research

Dhilan Desai has gardening experience with the garden at his home. Quick research into plant transpiration -- the loss of water through the leaves -- reveals the main influencing factors include temperature, relative humidity, soil moisture, and type of plant. The MudPi system is a product that has a similar goal but is useful for an entire garden, our project will be focused on a smaller scale for the more casual plant lover.

The microcontroller will turn on the water pump for a certain amount time when the soil moisture sensor has detected a low enough value for long enough. This amount will need to be experimentally determined for the pump with different types of soils and plants. Information from other sensors is not planned to be considered for pump activation at this time.

Block Diagram / Flow Chart

System Overview

Soil Moisture Sensor: Detects moisture content of soil.

The microcontroller will turn on the water pump for a certain amount time when the soil moisture sensor has detected a low enough value for long enough. This amount will need to be experimentally determined for the pump with different types of soils and plants. 

Temp/Humidity Sensor: Detects current temperature and humidity.

Sunlight Sensor: Detects presence and intensity of sunlight.

The other sensors are in place to provide alerts when the plant hasn't been receiving enough sunlight (again determined per plant) over the last three days or the temperature is dangerously high or low. 

Water Level Detector: Detects level of water in reservoirs. 

Water level detection will allow the screen to display an alert when the reservoir need to be refilled.

Brain/Microcontroller: Receives input from the sensors and “tells” the pump and display how to respond.

Pump: Signaled on to feed water into the plant.

ePaper Display: Receives input from the brain to display what the plant needs & alert the user to potential issues.

An ePaper disp has low power consumption and no drain when not writing to display.

Parts

Incomplete, need to hash out exact circuit diagram for water level detector and pump power.

Possible Challenges

Designing the pot to include all the required sensors (and a reservoir?) in effective positions.

Placing the soil sensor in a position to effectively track overall saturation and drainage.

Placing the sunlight sensor so that it isn't blocked by the plant itself.

Perfecting the "health alerts" to determine when an amount of sunlight or temp isn't enough/too much.

References

[1]"Evapotranspiration and the Water Cycle", usgs.gov. [Online]. Available: https://www.usgs.gov/special-topic/water-science-school/science/evapotranspiration-and-water-cycle. [Accessed: 19- Feb- 2021]

[2]R. Zwetsloot, "MudPi water automation system", The MagPi magazine. [Online]. Available: https://magpi.raspberrypi.org/articles/mudpi-water-automation-system. [Accessed: 19- Feb- 2021]

[3]"Simple Water Level Indicator", Circuitstoday.com. [Online]. Available: https://www.circuitstoday.com/simple-water-level-idicator. [Accessed: 19- Feb- 2021]