Project 2 – Rent Out Your Parking Space

In this chapter, we will complete another exciting project that explores the intersection of technology, convenience, and practicality. Our mission is to create a prototype to rent out your parking space, with the help of an ESP32 microcontroller and the versatile PayPal API.

The concept of renting out your parking space might seem simple, but it’s a brilliant example of how IoT and APIs can be harnessed to streamline everyday tasks and even generate income. This project not only serves as a prototype but also lays the foundation for a real-world application that can benefit both parking space owners and those in need of parking.

In this chapter, we will dive into the details of interfacing the ESP32 with the parking space, setting up a payment system using the PayPal API, and creating a seamless user experience for potential renters. We will explore the technical aspects of monitoring parking availability, accepting payments...

Technical requirements

For this project, we will need the following:

• An ESP32 Dev kit board
• A Servo motor
• An ultrasonic sensor
• A push button
• An RGB LED
• An SSD1306 OLED
• A PayPal account

Interfacing sensors with ESP32

In this section, we will dive into the hardware of our parking space rental project. Here, we will explore the integration of a diverse array of sensors and actuators with the ESP32 microcontroller, enabling us to enhance the functionality and user experience of our prototype.

Our project relies on the seamless coordination of various components to monitor parking space availability, handle secure payments through the PayPal API, and ensure a user-friendly experience. To achieve this, we will connect the ESP32 with essential components, including an ultrasonic sensor, an SSD1306 OLED I2C display, a Servo motor, an RGB LED, and a push button.

The ultrasonic sensor enables precise measurement of distances, a crucial aspect of monitoring parking spaces. The SSD1306 OLED I2C display provides visual feedback to users, displaying relevant information about parking availability and transactions. The Servo motor gives us the ability to control physical...

Integrating the PayPal API

In this section, we will set up the Webhooks that will enable us to receive a notification related to the payment in the ESP32. To set up the Webhooks, we will complete the following steps:

1. Firstly, we will go to https://www.webhook.site and get a unique URL, as highlighted in the following figure:

Figure 7.4 – A unique URL on Webhook.site

2. Then, to test our Webhook, we will use the PayPal Instant Payment Notification (IPN) simulator. It will help us to simulate the payment notification for testing. To access the IPN simulator, go to https://developer.paypal.com/dashboard/ipnsimulator using your web browser.
3. Paste the unique URL into the IPL URL handler, and select Web Accept as the transaction type.

Figure 7.5 – The PayPal IPN simulator

4. For testing, leave all other values to default, and then go to the bottom of the page and click on Send IPN.

...

Creating a user-friendly experience for potential renters

By now, you will have noticed that the code contained in each of the preceding sections was just a small part of this project. In this section, we will combine everything to create a user-friendly experience for potential renters. The following is the flow chart for this project:

Figure 7.9 – The project flow chart

The preceding flow chart shows the flow of the commands and instructions for various scenarios – that is, when the payment has not been made and the car is not parked or parked, and when the payment has been made and the car is parked or not. The flow chart will help us understand and create a logic to write the final code of the project. The final code has all the functionalities that we have previously discussed in this chapter. It will wait for the button press, read the sensor data, wait for the payment, and show the parking status on the OLED. The code is available...

Real-world implementation and project limitations

The project we have developed is a prototype that employs a Servo motor to simulate the function of a barrier gate. In actual operational scenarios, it’s important to note that the SG90 Servo motor used in this prototype is insufficient to serve as an effective barrier gate. In practical applications, a dedicated parking barrier system is required, which, depending on its configuration, can be integrated with the ESP32. An example of a more robust setup might involve using a relay board to control the barrier, as shown in Figure 7.15.

Figure 7.15 – A practical implementation of the project

Additionally, for real-world scenarios, access to a parking space should only be granted after a successful payment. In our prototyping, we used the PayPal IPN simulator to test payment functionality. To get notifications when someone pays you on PayPal, we will complete the following steps:

1. Log...

Security concepts in IoT

In the field of the Internet of Things (IoT), ensuring robust security is paramount to safeguarding connected devices and the data they generate. Several key security concepts are integral to fortifying IoT ecosystems. Some of them are defined here:

• Authentication: Authentication is a critical security concept in IoT, verifying the identity of devices and users seeking access to a network. This process involves confirming the legitimacy of entities through various mechanisms such as passwords, biometrics, or digital certificates. By implementing strong authentication protocols, IoT systems can stop unauthorized access and mitigate the risk of compromised devices compromising the entire network.
• Encryption: Encryption plays a pivotal role in securing data transmitted between IoT devices and networks. Employing encryption algorithms ensures that the information exchanged remains confidential and tamper-resistant. Both symmetric and asymmetric encryption...

Summary

In this chapter, we embarked on a practical project focused on enabling the rental of parking spaces, through the integration of Webhooks and PayPal IPN. To bring this project to life, we used various components, including ultrasonic sensors, Servo motors, and OLED displays in the prototyping phase. These components allowed us to create a system that facilitates the access and payment process for parking spaces.

Looking ahead to the next chapter, we will delve into the development of a data logger, expanding our exploration of IoT applications into a different realm. This project promises to further extend our understanding and practical skills in the realm of IoT.