The Internet of Things (IoT) has revolutionized how we live our lives, especially regarding home automation. Event-driven architecture (EDA) is a natural fit for IoT applications, where devices generate events based on changes in their environment or behavior. EDA can help build scalable and efficient IoT systems by enabling real-time processing of events and allowing for decoupling of different components. For instance, in a smart home application, sensors installed in different rooms can generate events based on temperature, humidity, light, and occupancy. In combination with Solace, the leading enabler of EDA for real-time enterprises, EDA can enhance the process of building smart home automation applications by enabling efficient data processing, real-time event streaming, and secure data exchange between devices and applications
EDA is an approach to building software systems where the system reacts to events triggered by changes in state or behavior. Events are the key driving force for communication and data flow between system components. EDA allows for loosely coupled components that can communicate and collaborate in a reactive and scalable way, enabling systems to handle complex and dynamic workflows. EDA is commonly used in real-time applications such as IoT, financial trading, and healthcare, where events are constantly generated and must be processed in real-time.
Solace makes event-driven messaging middleware called PubSub+ Platform that provides a scalable and secure way to transmit data between different system components. PubSub+ enables efficient real-time messaging across different networks, clouds, and devices, making it ideal for IoT, cloud-native, and hybrid environments.
EDA and Solace products can enhance smart home automation by enabling real-time data processing, efficient messaging, and scalable system design. In a smart home environment, EDA can process events generated by various sensors and devices, such as motion, temperature, and door sensors.
A smart home automation application using EDA and Solace can have several key features that enhance the home automation experience. Here are some examples of features that can be included:
Here are some examples of how each feature could be used to enhance the user experience:
Smart home automation applications using EDA and Solace can offer various use cases, such as energy management, security, convenience, healthcare, and entertainment. In this section, I’ll discuss some specific use cases where they can be beneficial.
Building a smart home automation application using EDA, Solace, and the ESP32 microcontroller effectively improves energy management, security, convenience, healthcare, and entertainment in smart homes. The ESP32 microcontroller is a low-power device that supports wireless connectivity and various sensors and actuators. By integrating it with EDA and Solace products, you can build scalable and reliable smart home automation applications that can be remotely controlled and monitored.
Here’s a high-level overview of the steps involved in building a smart home automation application using EDA and Solace:
I’ll show you how to create a simple ESP32 application that responds to external events and publishes them to Solace PubSub+ Event Broker using the EspMQTTClient library.
Start with setting up the event broker using the official Getting Started guide.
Next, you have to install the EspMQTTClient library from the Arduino IDE. Follow the next steps:
After the installation is completed, open a new sketch (file).
Start by including the library.
#include "EspMQTTClient.h"
Continue by assigning internal variables that will be used later in the code.
#define humidityPin 5 const unsigned long period = 1000; // How frequently to publish the humidity reading in milliseconds unsigned long currentMillis; unsigned long startMillis; int humidityPct = 0;
Next, initialize the MQTT client using the WiFi and MQTT credentials.
EspMQTTClient client( "Your WiFi SSID", "Your WiFi password", "MQTT Server IP", // MQTT Broker server ip (usually your PC's IP) "MQTT Username", // Default: admin "MQTT Password", // Default: admin "TestDevice" // Client name that uniquely identifies your device );
If you’re connecting locally, the MQTT server IP will be the local IP address of your host device. In my case, it is 10.10.1.3, but your might differ and be something like 192.168.x.x, or any address from the private IP range.
Your local IP address is usually found in the network settings.
Next, create a function that subscribes to the topic and publishes a message upon connecting to the WiFi network.
void setup() { Serial.begin(9600); } void onConnectionEstablished() { Serial.println("Connection established"); client.subscribe("mytopic/test", [] (const String &payload) { Serial.println(payload); }); client.subscribe("mytopic/humidity", [] (const String &payload) { Serial.println(payload); }); client.publish("mytopic/test", "Connection established"); }
At the end, add the loop function to publish the event to the broker.
client.loop()
must be present in the loop()
since the client is “always” listening to events. Learn more about EspMQTTClient’s functions.void loop() { currentMillis = millis(); if (currentMillis - startMillis >= period) { humidityPct = analogRead(humidityPin); client.publish("mytopic/humidity", String(humidityPct)); startMillis = currentMillis; } client.loop(); }
You can now compile the sketch and upload it to the ESP32.
If no errors are thrown, you can head to http://localhost:8080 on your host device to access the Solace PubSub+ Broker Manager.
After logging in, you’ll be presented with the Message VPNs section.
Now click on default.
Now on the left panel, select Clients.
You’ll now have a Clients Summary, from which you can choose Solace Clients.
In the Solace Clients summary, you’ll see your device successfully connected to the broker as the #mqtt/primary/{device-name}
.
That’s it. Now you can implement external event triggering or sending events from Solace to the ESP32.
To explore more, please refer to the EspMQTTClient’s GitHub repository.
Bonus: Select Try Me! from the left panel to see the incoming messages.
On the right side of the screen, you’ll see the Subscriber section. Please press the Connect button to establish a connection.
Now, you have to subscribe to the topic defined in the ESP32 sketch. In the case of this guide, the topics are mytopic/test
and mytopic/humidity
.
To trigger the message “Connection established”, reset the ESP32, and a message should appear shortly in the broker.
Other humidity readings will appear every X milliseconds that you defined in the code.
To build a smart home automation application using EDA and Solace, you can utilize various resources and tools, including Solace PubSub+ Event Broker, AWS IoT Core, Arduino IDE, Node-RED, and OpenHAB. These tools and resources provide various functionalities, such as messaging, cloud connectivity, firmware programming, visual programming, and device management. By leveraging these tools and resources, you can create scalable, reliable, and efficient smart home automation features that enhance your application.
Combining EDA and Solace with IoT development may be beneficial for your application. External event triggering can be used to personalize end-user experience, increasing overall product satisfaction. A Solace-enabled IoT product can be built as a minimum viable product (MVP) first, proving the capabilities and benefits of EDA combined with products like PubSub+ Event Broker. To continue your EDA and Solace journey, you can look at How to Easily Publish Events from the Cloud to Solace PubSub+.