Build a Plant Monitoring System using Raspberry Pi, ThingSpeak and IFTTT

In this post, I have briefly explained how to build a smart Plant Communication System using Raspberry Pi, Sensors, ThingSpeak, and IFTTT. 

 Outline

• Overview
• Hardware Requirement
• Software Requirement
• Soil Moisture Sensor
• Light Intensity Sensor
• IFTTT Webhooks
• Wiring Sensors to Raspberry Pi
• Configuring Raspberry Pi
• Setting Up ThingSpeak and IFTTT account
• ThingHTTP and React App
• Output Screenshots

Overview

"To Plant a Garden is to beleive in Tomorrow "

The health of any plant largely depends on two main factors. They are moisture content and exposure to light. However, there is no way for plants to communicate their needs and requirements to humans. Thus, in order to bring out a solution, I have made an IOT-based plant communication system using Raspberry pi, sensors, ThingSpeak cloud and, IFTTT. In this experiment, IFTTT will act as a communicator on behalf of plants. It sends a notification to your mobile whenever your plant needs water and/or light adjustment. 

Hardware Requirement

• Raspberry Pi
• Soil moisture sensor
• BH1750 Light intensity sensor
• Jumber wires

Software Requirement

• Python
• ThingSpeak
• IFTTT

Soil Moisture Sensor

The soil moisture sensor is an effective sensor used to gauge the volumetric content of water inside the soil. It uses high frequency capacitance technology to measure the dielectric permittivity of the surrounding medium. The output of this sensor is in the range 0 - 5Volt according to the water content and the sensor acts as open circuit when there is no water which gives 5Volt as output. The sensor is provided with both digital and analog output.

BH1750 Light Intensity Sensor

When it comes to growing indoor plants, it is very important to know that the light intensity of sunlight coming through the window is at optimal levels. Thus, to maintain our plants under optimal Lux values, we use a BH1750 light intensity sensor.  

BH1750 is a digital light intensity sensor which uses I2C bus interface for communication. It is equipped with built in AD converter which is responsible for obtaining 16 bit digital data. This sensor can accurately measure the light intensity in terms of LUX units, whose value ranges up to 65535lx. Click BH1750 sensor datasheet for more details.

IFTTT Webhooks

IFTTT stands for IF This Then That. It is a web-based automation tool that supports numerous services like apps, websites, smart home devices, etc. Webhooks is one such service provided by IFTTT that allows users to integrate with other IFTTT services using web requests. IFTTT uses applets to trigger an event when particular conditions are met. 

Wiring Sensors to Raspberry Pi

From the above figure, we infer the following details

1. Soil Moisture sensor
2. Connect the probes to sensor module
3. BH1750 Light Intensity Sensor 
4. Now, wire soil moisture sensor to Raspberry Pi
• Vcc  --> 5V
• GND --> GND
• DO (Digital Output) --> GPIO 26
5. Connect BH1750 sensor to Raspberry Pi
• Vcc  --> 3.3 V
• GND --> GND
• SDA  --> GPIO 2 (SDA I2C)
• SCL  --> GPIO 3 (SCL I2C)
• ADD (Address Select) --> GND

Configuring Raspberry Pi

Once the wiring part is over, the next step is to configure Raspberry Pi as per the requirements. We need to perform two tasks to enable our sensors for use.

Enable I2C Interface

To program BH1750 light intensity sensor, we must first enable I2C interface on our Raspberry Pi. The I2C interface can be enabled either from terminal window or Raspberry Pi Configuration option. Here, I will use "Raspberry Pi Configuration"

Click on Applications menu > Preferences > Raspberry Pi Configuration. 

This window will show up

Go to Interfaces tab and click on "Enabled" radio button for the I2C option. Finally  Click on OK button and reboot the Raspberry Pi. The I2C interface will be enabled after rebooting.

Install Python Library

The SMBus (System Management Bus) library package provides support to access I2C devices for communication on Raspberry Pi. Run the following command from the terminal to install SMBus packages.

pi@raspberrypi:~ $ sudo apt-get install python-smbus python3-smbus

Setting Up IFTTT and ThingSpeak Account

Creating an IFTTT Applet

IFTTT is a web platform that you can use to establish connections between different services, apps, websites and, devices in order to trigger an event to perform automation involving those services, devices and, applications. The applet is the main element of IFTTT which can be configured based on our requirements. The steps to create an applet are as follows.

First of all, we need to create an account on IFTTT. Head to the IFTTT website and Sign up (If you are a new user) or Log in (If you already have an IFTTT account). Once you have logged in, click on the "Create" option in the top right of the windwo
This window will show up.

Click on the "Add" to select the Trigger service for your applet. From the list of services displayed, search for "Webhooks" in the search bar and select it. 

The above window will be displayed. Choose either "Receive a web request with a JSON payload" or "Receive a web request" as per your requirements. We will be proceeding by clicking on the "Receive a web request" option.

In next window, you will be asked to give a name for your Event that needs to be triggered. Give proper Event name with no space in between.I will name mine as "Plant_Communicator". Then, Click "Create Trigger".

The "If This" part of our applet is completed. Let's move on to "Then That". Click on the "Add" and select "Notifications" service from the list of services displayed. The Notifications service forms the "Then That" part of the applet and will be integrated using Webhooks IFTTTx.

Based on your requirements, choose either of these. We will be proceeding by selecting "Send a notification from the IFTTT app". 

Next, you will be asked to customize your Message format that will be sent to your mobile. Click on the "Add ingredient". You can customize your message by adding ingredients and rephrasing it as per our requirements. 

Finally, click "Create action". Press continue and proceed. The final page lets you to check status (Connected or Disconnectd) of your applet. We can edit title for our applet as per our need.

Click on the Webhooks logo. Webhooks Integrations page will open. Click "Documentation". Here you can find a web URL with your key to make a POST or GET web request. Make copy of the IFTTT Webhook url which will be used later to connect with your ThingSpeak application.

Configuring ThingSpeak Account

ThingSpeak is an Internet Of Things (IOT) cloud platform service that provides real time visualization and monitoring of data posted by your devices. It enables IOT things like sensors, instruments, and websites to send and log data to the cloud server so that we can visualize, aggregate, store and analyze results. 

If you are new to ThingSpeak, please Click here to read about how to setup and sign up a ThingSpeak Account. 

After logging in to your ThingSpeak account, create a new channel by clicking on the "New Channel" button. In my case, I have named my channel as "Plant Communication System" and defined two fields each for Light intensity and Soil Moisture sensor. Click on the Save Channel button.

Click on the "API Keys" tab and make a copy of API Key values to use it in Python code. Once we have configured ThingSpeak channel, the next step is to setup ThingHTTP and React apps for out project.

ThingHTTP and React App

ThingHTTP is a web-based free application from ThingSpeak community. It provides communication paths among web services, devices, and other web applications using HTTP over the internet. The React app works with the ThingHTTP app to trigger an HTTP request when our data posted on the ThingSpeak channel meets a certain condition.

In this project, ThingHTTP app will be used to specify actions in order to trigger our IFTTT applet ("Plant_Communicator"). The ThingHTTP app will in-turn be triggered using React app when particular conditions are met. The following image represents IFTTT, ThingHTTP and React in a single frame.

Configuring ThingSpeak ThingHTTP Actions

Head back to ThingSpeak and select ThingHTTP from Apps menu. Click New ThingHTTP, and fill out the required fields. Fill the URL field with the IFTTT webhook URL. Also select GET as method. Click on the Save ThingHTTP button. Thus, when called, the ThingHTTP will create an HTTP GET request to the IFTTT applet.

Configuring ThingSpeak React App

Go to ThingSpeak and select React app from the Apps menu. Click on the "New React" button. Fill out the required fields.

• React Name : Plant Communicator
• Condition Type : Numeric (Since output LDR sensor will be in decimal)
• Test Frequency : On Data Insertion
• Condition : Light Intensity field value greater than 3000 (Optimal Lux value for my indoor plant)
• Action : ThingHTTP
• Action (then perform ThingHTTP) : Plant Communicator (Your ThingHTTP name)
• Option : Run action each time condition is met

Click Save React. Now create a similar React for Soil Moisture sensor to find the presence of water content in the plant soil. In case of absence of moisture content, trigger an HTTP request to IFTTT applet.

Python Code 

Click the button below to download the python code. Make sure that you replace API Keys with that of yours.

 Output Screenshots