Design Specifications

 Initial Phase

Written Ideas/sketches/drawings/images with descriptions.

Our idea to facilitate and promote plant growth consisted of 3 components. The first component is a self watering system, the second component is a nutrient refill system and the third component is the usage of hydrogel extracted from diapers.

As seen in the sketch below, our initial design was simpler whereby mung beans were grown on top of a layer of hydrogel which is extracted from baby diapers. The hydrogel will be laid on a woven fabric which provides mechanical support for the plant.

Initial idea

The smart watering system we proposed will automatically water the plants 4 times a day until the water sensor detects that the nutrient concentration in the solution falls below a threshold value. Watering stops and the user is alerted to refill the nutrient reservoir with fresh solutions.

Smart watering system flowchart

Prototype

1st Prototype

Prototype images/videos with descriptions.

After feedback and advice from the lecturers and professors, we made some modifications to our initial idea and added new features that will improve plant growth rate.

Firstly, we decided to choose a suitable growing medium that would work the best with hydrogel, and decided upon zeolite after conducting a preliminary experiment with various other growing mediums.

 

New prototype with layering system

We also decided on incorporating an IoT cloud with the Arduino boards we currently have to unify the components necessary for the project.

New block diagram
2nd Prototype

For our 2nd prototype, we decided to replace hydrogel with hydrorock as we discovered hydrorock has better water retention capabilities.

Hydrorock added to the bottom

We also replaced the NPK sensor with a TDS sensor to increase the precision of measuring the concentration of nutrients as it allows the number of particles to be sensed.

Diagram of how the TDS sensor works

Additionally, we incorporated the UV light into the Arduino IoT system so that the user can control the timing at which the lights are switched on.

Interface of Arduino IoT showing how the UV lights can be scheduled
Final Product

Here is a sketch of our final design.

Here is the block diagram of our final product.

Here are the pictures of our final product.

From Prototype 2 to the final product, there were not much changes to the design, except in the addition of wheels and the waterproofing of electronics using corrugated boards.