Show HN: PythonECG – A minimal real-time ECG visualization tool

I built a lightweight Python application that visualizes audio input as an ECG-like display. It's a simplified, open-source tool designed for educational purposes, signal visualization experiments, and prototyping. No commercial restrictions, just a clean interface with a single button to start/stop tracing. Built with PyAudio, Matplotlib, and Tkinter. Looking for feedback and contributions!