Live Stream Coding: Improving the Vaadin+Spring+Pi4J demo application with Matti Tahvonen

During a live stream coding session, Matti Tahvonen and I updated an existing Vaadin+Spring+Pi4J demo application to use the latest version of the libraries and Java 25. It’s a demo application I created a few years ago to using during presentations at conferences. Of course, everything evolves, so a big update and refactoring was needed.

(Sorry for the hiccups in the first minutes, my network connection dropped a few times…)

Links from this video:

• Sources of the demo application
• Pi4J project
• Vaadin components
• Vaadin directory
• Vaadin 24.9 release notes
• Gauge component
• Notifications with Vaadin
• Start your Java application at Linux startup
• MelodyMatrix, a website created with Vaadin
• Using a Raspberry Pi as HDMI camera

However, during the live session, we were unable to build the application for the Raspberry Pi as we had an unexpected error. But the problem was quickly fixed after we finished the stream, as you can see in the video below. And we now have a nice graphical view of the temperature and humidity measured with the DHT11 sensor on the CrowPi 2.