Project 1 – Smart Plant Monitoring System Using ESP32, Messaging Services, and the Twitter API

In this chapter, we will use all the knowledge we gained in the previous chapters and complete an innovative project where we’ll integrate various sensors with a plant to create a smart and interconnected ecosystem.

Our project revolves around the concept of enhancing plant care and communication. We will dive into the details of interfacing sensors with an ESP32 microcontroller, enabling the plant to gather and process data about its environment. The data will be sent to the owner of the plant, which will set the foundation for informed decision-making.

What sets this project apart is its extensive use of messaging services and APIs to establish communication channels between the plant and the digital world. We will explore how the plant can send real-time updates via Gmail, WhatsApp, and Telegram, ensuring that you are always in the know of your plant’s wellbeing...

Technical requirements

For this chapter, we will need the following hardware and software components:

• ESP32 dev kit
• Capacitive soil moisture sensor
• DHT22 temperature and humidity sensor
• Google account
• The CallMeBot API
• The Twitter API
• WhatsApp and Telegram accounts

All the code files used in this chapter will be available at https://github.com/PacktPublishing/Programming-ESP32-with-Arduino-IDE/tree/main/Chapter6

First, let’s interface the sensors that will help us gather some useful data from our plant.

Interfacing sensors with ESP32

In our first topic, we’ll dive into the foundational step of our project: connecting and interfacing two crucial sensors with the ESP32 microcontroller. These sensors – the moisture sensor and the DHT22 temperature and humidity sensor– play pivotal roles in providing essential data for our smart plant monitoring system. The moisture sensor allows us to monitor soil moisture levels, ensuring our plant receives the optimal amount of hydration, while the DHT22 sensor provides valuable insights into the surrounding environment, including humidity and temperature data. This initial phase sets the stage for our project’s success by establishing the means to gather critical information about the plant’s well-being and its immediate surroundings. We’ll explore the wiring, configuration, and data retrieval from these sensors, laying a strong foundation for the interconnected ecosystem we aim to create for our smart plant...

Sending emails using SMTP

Simple Mail Transfer Protocol (SMTP) is a fundamental communication protocol that’s used for sending electronic mail (email) messages over the internet. It operates as a set of rules and conventions that enable email clients or servers to transmit messages to their intended recipients. SMTP governs the process of routing, relaying, and delivering emails, making it a core component of email communication worldwide. Its simplicity and efficiency make it a widely adopted protocol for ensuring the reliable exchange of electronic messages across diverse email platforms and services.

In this section, we’ll dive into the integration of SMTP within our ESP32-powered smart plant monitoring system. Email communication proves to be an invaluable tool in keeping plant enthusiasts informed about the well-being of their green companions. By harnessing the power of SMTP, our system can send email notifications and updates directly to the user’s inbox...

Using the CallMeBot API to send WhatsApp and Telegram messages

The CallMeBot API is a powerful tool that enables users to seamlessly send WhatsApp and Telegram messages programmatically. This versatile API simplifies the process of integrating messaging services into applications, making it accessible for a wide range of purposes. Whether it’s sending automated notifications, alerts, or personalized messages, developers can harness the capabilities of CallMeBot to enhance user engagement and communication. By leveraging this API, businesses and individuals can create innovative solutions that connect with their target audience via WhatsApp and Telegram, enriching their digital interactions and streamlining communication channels. With the CallMeBot API, messaging integration has never been easier, providing a versatile platform for modern messaging needs.

In this section, we will add more functions to our project that will enable us to send WhatsApp and Telegram messages...

Publishing update tweets on Twitter

Using the Twitter API and ESP32, you can easily post tweets, providing a quick and efficient way to share updates and information on Twitter. In this section, we will set up the Twitter API so that we can publish the tweets from ESP32.

Setting up the Twitter API

Firstly, we will set up the Twitter API:

1. To publish the tweets on Twitter (now known as X), we will have to create an account. I have already created an account called @plantNeedWater:

Figure 6.21 – Twitter @PlantNeedWater account

2. After making an account, sign up for a developer account at https://developer.twitter.com/en.
3. Select the Free account and click on Get started:

Figure 6.22 – Twitter API plans

4. Click on Sign up for Free Account and then accept the agreement and policy:

Figure 6.23 – Sign up for Free Account

5. Now, you will have...

Summary

In this chapter, we embarked on a comprehensive exploration of IoT applications, focusing on the vital task of environmental monitoring. We began by delving into the intricacies of reading moisture levels, as well as tracking temperature and humidity data. These critical measurements provide us with invaluable insights into our surroundings, enabling us to make informed decisions and take appropriate actions.

Building upon this foundation, we explored the power of email communication by employing SMTP. This allowed us to send messages and alerts directly to email recipients, providing a reliable means of information dissemination and communication.

Furthermore, we dived into the exciting realm of communication and automation. Leveraging the CallMeBot API, we honed our skills in sending specific messages through popular messaging platforms such as WhatsApp and Telegram.

In addition to real-time messaging, we dived into the world of social media and harnessed the Twitter...