Creating a Visual Clue when reading from Serial Port

I’m reading data streaming from the serial port. I have a visual display:

At rest, the display typically reads zero as per the image above. However, there are fluctuations.

When the user looks at the screen, it may appear that nothing is happening! - theoretically, this could go on for 10’s of seconds and leave the user unsure of what’s happening and/or what to do next.

One method to show that something is happening, would be to have the text “LIVE: Reading incoming Data . . .” add more dots (full stops) at the end, ie. progressive . . . . . . etc. then reset. I’m familiar with this scenario but looking for something else/ideas.

A turning wheel is not good as it invokes feelings of unending doom. A progress bar won’t work because the progress could be infinite.

The “good old” dot. dot. dot . . . . may well be the best visual representation. Moving arrows perhaps? ? ?

Traditionally serial devices had leds that flashed when tx/rx data. You may simulate 1 (or 2) leds that became red when receiving/transmiting data and grey (or black) when not.