Final Project | Kishor Gaikwad- Fab Academy 2022

Title: Cost-effective IoT based smart onion storage system

Problem Statement

In India and other developing countries, there is almost 40-80% of onion harvested is spoiled because of various reasons. One of the prominent reasons is in-proper handling and unscientific ways of storage. Also The cost of cold storage is almost 10-12 times the cost of natural ventilated storage and 20 times than the traditional unscientific ways of storage, which is too high for a marginal farmers of a developing country like India.

This problem results in major social and health problems in India as a consequence of major finacial losses to the farmers.

Objectives of the Project

My objective is to solve the storage related spoilage, rotting and losses through a cost-effective, IoT based smart mechanism of post-harvest onion bulk storage.

The onions need to be stored in well ventilated area. My idea is to measure the temperature, humidity in and outside the storage room along with measuring the levels of Methane gas emmitted by onions stored. More the level of methane means the onions have started rotting. Upon measuring and monitoring the humidity, temperature and the methane concentration, the storage house will be ventilated and aerated sufficiently to keep the produce dry and cool.

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Abstract

Having been cultivated for 5,000 years, the onion has been a vital part our salads and meals along with its countless health benefits and strong aroma. The onion is the oldest and most widely used vegetable that can be cultivated in all types of soil all around the world. Being an irreplaceable aroma for the meals, the onion creates a large economy with the production of almost 100 million tons of round the world. The United Nations reports that the onion is grown in at least 175 countries and this figure doubles the number of wheat growing countries. Asia is the largest producer of the onion with a market share of 65 percent, while the Americas, Europe and Africa each has just over 10 percent of the market share.

China is the leader of onion production with 23 million tons in Asia and followed by India with production of over 19 million tons. China and India are followed by the United States with the production of over 3 million tons. Other large onion producers are respectively Iran, turkey, Pakistan, Egypt, Brazil and Mexico.

Although Asia has the biggest share in terms of production area and quantity, it does not rank as the leading Market in the global onion Market. This is due to high population density, insufficient storing spaces and the fact that they can't come out to foreign markets. While countries aim to increase their production for their citizens, they try to sell their surplus products on global markets for economic growth. If new investors prefer yellow onions considering the demands of developed countries markets, they should know that they would have a large market share. Nearly 90% of onions are consumed within the country they are grown. Therefore, the onion does not stand out in many parts of the world.

Traditional methods of storing onions are drying them with their stocks on and storing in a cool shelter, cave or dark storage after they are harvested until they are consumed. However, between 40 and 80 percent of the onion stored with this method result in spoilage. Neither economy nor our planet can afford these kinds of spoilage anymore. Onions now are stored in cold storage after the harvest. First onions need to be dried for a few days, then starts the maturing stage that enable skin and color formation to specific to the onion cultivated. Onions are prepared for cold storage by lowering the temperature at a maximum of 0.5 degree Celcius per day. Depending on the onion variety, they are stored at between 0 and 2 degrees Celsius in cold storage. Onions can be stored in cold storage up to 10 months without spoilage. Ventilation is vital in onion storage. After storing, onions are not transported straight from the cold storage before they are put on the market, but kept in temperature-controlled conditions in order to prevent condensation. Because of condensation, sprouting will happen immediately after they are taken out of cold storage resulting in poor pricing in the market.

Cold storages involve little difficult and elaborate processes and it is still not able to solve the problems of a marginal farmers in developing countries. The cost of cold storage is also a major factor, which is almost 10-12 times the cost of natural ventilated storage and 20 times than the traditional unscientific ways of storage, which is too high for a marginal farmers of a developing country like India.

Types of rotting and infections in onions

Only 20 million tons of global onion production of 100 million tons are stored with modern storage methods and spoilage still continues. Weight loss, sprouting of bulbs, rotting, bacterial and fungal infections are some of the ways the onion spoilage happen. Neck rot (rotting at the neck of the onion), bacterial rot, basal rot (fungus infection through wounds and scars at the base of the bulb) and other diseases are resulted out of improper storage.

In developing countries like India, proper handling and unscientific ways of storage is a matter of great concern. Onions are stored in poorly ventilated temporary structures. Each farmer has created their own storage method based on their needs, experience and resources available. These unscientific ways of storage result in higher losses in storage. Actually, losses start immediately after harvesting. The facility of onion storage post harvesting needs to be made available right at the time of sowing of seeds itself.

Social and Health Problems:

The marginal farmers in India, who can neither afford the cost of cold storage nor the huge of produce losses. With less to none yield, these farmers end up in committing suicides, which is a major social and financial issue. At the same time, to save their crop from these spoilages, they use a lot of pesticides to prevent these infections post harvesting. This ultimately results in creating long term health problems for people.

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Sketch of the Final Project

Following is a sketch of the proposed cost-effective IoT based smart onion storage system.

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Computer-aided Design

Creating 3D objects and Assembly of Parts of my Final Project in Solidworks

I used SolidWorks to create 3D models of some of the parts of my Final project. I also used Assembly module to create a basic assembly of my final project. I used rendering to change the appearance, texture and colors of the components.

First, I created 3D models of some of the major parts of my final project concept. I then assembled them as shown below.

I used animation wizard in Solidworks to create a small animation of the final assembly for better visualtion of the project through animation. Please find below the video. For more details on this, pls go to my CAD assignment.

However, this design was my initial thought. I later decided to design and set-up cost-effective storage system that is most common amongst the farmers in our nearby farm community. Following is my new design.

Following are the pictures of storage system designed and actual storage system I fabricated. I arranged these two pictures side-by-side to compare designed vs actual set-up.

Following is a picture of the CAD model that I later designed for 3D printing the enclosure for electronics of the system.

Following are the pictures of enclosure designed and actual enclosure I 3D printed and assembled. I arranged these two pictures side-by-side to compare designed vs actual assembly.

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Electronics Design

Designing my final project board- 1st attempt

I designed my final project board in the week of output devices. I also milled and stuffed my final project board in that week only. I made an attempt to program this board. However, I could not program it because of some issues that I have explained below.

To begin designing my final project board, first I referred ESP32-WROOM-32 Data sheet to find out the pin-out of the IC to design my board. Below are the important specifications I looked in to while selecting ESP32-Wroom32 micro-controller for my final project board.

For more details on this, pls go to my 'Output Devices' assignment.

Below is the pin-out of ESP32-Wroom32. After understanding the pin-out and description of each pin from the datasheet, I chose pins for input and output devices that I will be connecting to my project board as shown below.

I then converted this table to an excel sheet for me to be able to map each pin to their respective input and output devices as shown below.

Using Eagle to design my final project board

I downloaded esp32 library for adding ESP32-Wroom-32 microcontroller IC to my shcematic and board as shown below. I referred this website to download the ESP32 library.

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Electronics Production

Milling my final project board:

For more details on this, pls go to my 'Output Devices' assignment.

Stuffing my final project board:

Components Required for my Project board:

1. Resistor: 10K- 1 Qty
2. Capacitor: 1uF- 1 Qty
3. Capacitor: 10uF- 1 Qty
4. Capacitor: 0.1uF- 1 Qty
5. Push button (No)- 1 Qty
6. Sliding switch- 1 Qty
7. 3.3v voltage regulator (SMD)- 1 Qty
8. Microprocessor ESP32 Wroom- 1 Qty
9. FTDI Pin (6pin)- 1 QTY
10. 4x1 make header pins

Issues with my final project board:

I designed, milled and stuffed my final project board. When I started to upload a basic program in to my board, it was giving timeout error. I checked connectivity between all connected points in the board and could not find much. I still kept facing the same timeout issue multiple times. So, my instructor Mr. Suhas and I decided to check the schematic one by one. We found out I did not make following connection in my schematic and there was not trace obviously.

So, I had to place a jumper wire between GND and one end of capacitor that is connected to the sliding switch as shown below. My board started working and programs started uploading. However, I did not try using this board at all for any output device for this week because of the time crunch and machine week was my priority, so I stopped here and used my board in input devices week onwards. I have documented it in those assignments.

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Input and output devices for final project

For more details on this, pls go to my 'Input Devices' assignment.

DS18B20 Temperature sensor

The DS18B20 is a 1-wire programmable Temperature sensor from maxim integrated. It is widely used to measure temperature in hard environments like in chemical solutions, mines or soil etc. The constriction of the sensor is rugged and also can be purchased with a waterproof option making the mounting process easy. It can measure a wide range of temperature from -55 Deg C to +125 Deg C with a decent accuracy of +/- 0.5 Deg C. Each sensor has a unique address and requires only one pin of the MCU to transfer data so it a very good choice for measuring temperature at multiple points without compromising much of your digital pins on the microcontroller. This is an advanced level protocol, where each sensor can be set with a 64-bit serial code which aids to control numerous sensors using a single pin of the microcontroller.

It supplies 9-bit to 12-bit readings of temperature. These values show the temperature of a particular device. The communication of this sensor can be done through a one-wire bus protocol which uses one data line to communicate with an inner microprocessor. Additionally, this sensor gets the power supply directly from the data line so that the need for an external power supply can be eliminated. The applications of the DS18B20 temperature sensor include industrial systems, consumer products, systems which are sensitive thermally, thermostatic controls, and thermometers.

DS18B20 Pin Configuration

-Pin1 (Ground): This pin is used to connect to the GND terminal of the circuit
-Pin2 (Vcc): This pin is used to give the power to the sensor which ranges from 3.3V or 5V
-Pin3 (Data): The data pin supplies the temperature value, which can communicate with the help of 1-wire method.