RooftGrow – A Smart Community Urban Farm

1. Project Introduction

This project is part of the innovation and design Porgram(iDP) 3301R course, a year-long project that aimed to challenge our design thinking, problem-solving, and engineering skills. In this project, my team and I designed and built a community hydroponics farm with automated nutrient dosing and environment monitoring capabilities.

We were inspired to create a compact vertical community hydroponics farm after our interviews with residents residing in public housing in Singapore revealed that there was generally a lot of interest in farming crops; however, many do not pursue their interests due to the lack of space and availability of community allotment plots for farming.

The vertical farm was designed in such a way that each individual vertical tower was allocated to each resident interested in our farming system, and users could monitor the crops using a smartphone application without having to physically go to the setup. An automated system also targeted those who did not have too much of time to spend growing crops due to work commitments, but were nonetheless interested in farming.

My Responsibilities

I was the team lead and the following were my responsibilities:

      • Managing the team and deadlines

      • Ordering and Sourcing for Components

      • Designing and creating, and integrating the electronic components.

      • Designing the software for the system.

    Product Development Process Overview

    Product Development Process Overview

    2. Identification of Pain Points

    Methodology

    Our main method of understading residents pain points was conducting door-to-door knocking in Singaporean Public Housing Flats. Around 80% (HDB, 2024) of Singaporean residents stay in public housing, making it a reliable data source for our preliminary research and a potential target group.

    We also conduted surveys within various student chanels and personal connections to understand the pain point they faced. However, due to higher levels of inaccuracy of data, we only used the survey results as a secondry reference. 

    Value Proposition Canvas

    Based on our research data, we devised a value proposition canvas stating the pain points which we have identified and categorised it accordingly into needs, wants and fears. Based on the analysis of these pain points, we devised how a potential product could look like to address their pain points, stating the benefits of the product, potential features and an expereince the user could expect to gain out of it.

    3. Ideation and Concept Development

    Experimentation

    To develop a comprehensive hydroponic system, we realized that none of us had prior knowledge of farming or growing any crop-based plants at home. To familiarize ourselves with the problems our potential customers might face, we first needed to put ourselves in their shoes. Before ideating a system, we utilized home-based hydroponic setups to attempt growing crops ourselves. This also involved experimenting with various types of indoor growing lights to potentially implement an indoor solution.

    Understanding Current Developments

    In order to devise an ideal mechanical design of our setup we studied severeal different hydrophonic setups, from horizontal to vertical setups and hanging to non-hanging designs. We also needed a solution for the hydrophonic nutrient dosing system and a housing for the sensors. Some of the ideas we fould on our research are as follow. 
     

     

     4. Prototyping and Design

    Based on our research, we devised that our prototype should have the following features: 

    1. A vertical Tower System – To increase number of plots per tower for greater yield per area
    2. A Hovering Tower – To allow better flow of water and more even nutrient dosing
    3. A Rotatable Tower – To improve accessibility of the system from one side without having additional doors 
    4. A Transparent Enclosure – For penetration of sunlight and preventing harsh weather (eg. strong winds) from damaging crops
    5. Waterproof Electronics Housing for Electronic Components – To prevent water from damaging components in outdoor environment
    6. A Sensor Housing – To keep sensor at accurate levels for correct water level mesurements and sensor readings
    7. An App – For Environment Monitoring and Farming Education

    Initial Prototype Design Idea

    This is the very first sketch of our product design. While there were numeroud changes made through the journey, this served as a baseline of our design.
    Initial sketch of system
     
    One of the challengs we had was devising a method of rotating the tower. Given our limited mechanical knowledge at that time, we decided to take reference to whatever was around us. The closest that we could get was a bicycle wheel! So we tried to fit our tower to the wheel, unfortunately, it wasnt the best method due to the weight of the tower and unable to aim the sprinkler in a way that it could water all the plants inside the system evenly. We needed something sturdy and more reliable to allow the tower to hover in the water, without touching the base of the water reservoir. If the tower was to touch the bottom, the tower could be flooded with water leading to the drowning and eventual rotting of the plant roots. 
     
    Mechanical Design
    In our prototype, in order to showcase a comporable area to a community plot with more than 3x the crop yield, we decided to have the footprint of our system as similar to a community plot with 3 hydrophonic towers.  The towers had a common pump and a nutrient dosing system with 3 individual sprinklers for each of the towers. 
     
    CAD of our system
    Our Main System
     
    In order to secure the tower and allow it to rotate, we used acrylic sleeves and bearings to rotate the tower. The Water sprinkler hose would go through a opaque disk which is secured using a L bracket. The sleeve needs to be opaque in order to prevent sunlight from interacting with the water and nutrient solution which would result in algae formation. 

    In order to make it easier for residents to germinate their plants and place it into the main system, we created a germination station at the side of our system.

    Plant Germination Area

    Electronic System Design

    The Electronic system was designed comprising of the following: 

    1. Ambient Temperature and Humidity Sensor – to monitor environmnet parameters
    2. Lux Sensor – to measure amount of light received by the plants
    3. pH sensor – to monitor the pH of the system
    4. EC sensor – to determine the concentration of the nutrient solution
    5. DC motors – for nutrient dosing
    6. Flow Meter – to measure the water flow in the system
    7. Float Switch – to automatically allow water to flow throught the system when water levels are low
    8. A 12v Power Supply – to power up the entire system
    9. Arduino Microcontroller – to control the system
    Electronics System Design
     
    Here are the actual images  of the electronic system design: 

    Electronic and Software Integration Design

    System Architecture
     
    Source code for the Arduino Software component can be found here: Arduino Source Code Github
     
    Mobile App Design
    While we did not have the time to develop the entire Mobile app before the end of the project, we did a prototype of how it could potentially look like and how users could interact with it. 
     
    Some features of the app are as follows: 
    1. Statistics of the setup – pH, EC, Lux, Humidity Measurement, Picture of plants taken at certain intervals during the day
    2. Tips on Germination – Educate users on some common issues why play may not germinate properly
    3. Plant Info– Information on some common plants
    4. Subscription– Allowing users to subscribe to the system by tower purchase
    App Design for RooftGrow