Feel free to take a look at my repositories.
Most of them are records of studies and works I did in college, as well as some personal projects.
One of the works was the creation of a network communication application, implementing a text chat with audio transmission in real time. I developed an Android app with Java and Firebase: chat-firebase.
I also developed a low-cost system for remote monitoring of vital signs as part of my final paper.
The project uses the ESP32 development board, sensors and a blood pressure monitor: ESP32-health-monitor.
The most challenging was getting the blood pressure, I had to reverse engineer to hack the blood pressure device, the repository blood-pressure-monitor-hack has the details.