Datalogging with distance sensor

I am working on an art installation that is basically a 7 foot tall box with a proximity sensor embedded. My goal is to pull the data that gets printed to serial and save it securely in a file to be worked on later. My big constraint is that I am trying to avoid having to access a computer (that would need to be hidden away within the installation) or otherwise mess with the installation because that would disrupt the gallery showing and be awkward. Ideally, I would plug the whole installation into the wall to give it power, which would turn on the Arduino and start printing to serial. Here are a few options I've considered along with my concerns about them. I would love any ideas, as this is a unique situation that I haven't encountered.

  • Using my computer, I could simply copy and paste the data from the serial monitor into a text editor after I am done recording data. This is not ideal because I would have to both reach into the installation to bring up the serial monitor at the beginning and reach in to copy and paste the data after. And copy-paste might be riskier than writing to a file.
  • Using my computer, I could use terminal (I am using MacOS) to to write data from serial to a text file, but that would also require initializing that code, which would be disruptive.
  • Using my computer there might be another serial monitor analog that can also save the data like CoolTerm, but that has the same disadvantage as option 2.
  • Not using my computer, I could add a microSD card to my Arduino, and my code can write to the card instead of printing to serial. Opening, writing, and closing the write file every loop seems to be demanding, which might mess up the installation, which needs minimal delay to function correctly.

Again, my ideal solution would involve safe data logging, ability to do this without a computer (having to store a laptop within the art piece), and would start start without having to access the physical Arduino (besides providing power). I hope there is a creative solution. Thanks for the help!

You could record the data to SD and periodically retrieve the file(s) by Bluetooth.