Plant Health Monitor Project
Problem Statement:
While being preoccupied with schoolwork or other activities, my housemates and I have a hard time remembering to water the indoor plants due to lack of attention and a reliable reminder system that can seamlessly integrate into our daily routines. I need a product that provides a subtle and effective reminder for busy housemates to water our plants utilizing a simple and unobtrusive solution to maintain their well-being and enhance our living space.
Solution:
The Plant Health Monitor System is a device that utilizes capacitance technology to detect moisture in the soil of a plant. The device can subtly alert homeowners to water the plant since it has a light indicating its health status. The health monitor shows a green light for healthy soil, and red light for dry soil. Now, people in our house can easily get reminded of the state of our plants and we won't forget about them anymore.
Process
Materials:
- CPX Board
- USB cord / Battery pack
- Conductive Nail
- Alligator clip + wire
- Cardboard — for the structure
- Scotch tape — to hold it together
- Notecard — lens for the LED
- Scissors — make cuts
How it Works
The CPX board can detect the capacitance (the ability to store an electric charge) on an analog pin (in this case, analog pin A1). As the moisture around a nail in the plant's pot increases, the value increases (we're creating a bigger capacitor). Dry soil doesn't work as well for electricity (like most dry materials except metals) so the value read by the CPX will be lower.
Since the nail is attached to an alligator clip, it is able to hold a current through it. The product reacts once any electrical conductivity (water) is detected, and the light will turn green when it senses it. When there is no more current, the light responds by turning red. There is only one input, and that is the reading from the A1 pin. There are no other inputs, such as buttons or movement signals. There are also only 2 outputs, green light and red light.
Results
