while True: data = port.read(port.in_waiting or 1) bytes_rx += len(data) elapsed = time.time() - start if elapsed >= 1.0: bps = bytes_rx / elapsed print(f"Bandwidth: {bps:.0f} B/s") bytes_rx = 0 start = time.time() If you instead wanted (your own tool, not a copy of an existing v3.4), let me know the platform (Windows/Linux), programming language (Python/C#/C++), and specific features. I'll be happy to help you build a new, original version.