In ESP32 For Busy People, I have a section on the SPIFFS, the SPI file system. In this section, I show you how you can upload a file (like an image, or a text file) to your ESP32 and then use it in your sketches.
One thing I did not show was how to retrieve a file from the SPIFFS. For example, you may have a sketch that logs sensor data to a text file. How can you retrieve that file so you can process it on your computer?
A straight-forward way to do this is to run a simple web server on your ESP32. Using a browser, you can use this web server to download any file in the SPIFFS.
If you have installed the ESP32 Arduino Core in the Arduino IDE, you can use one of the example sketches that come with the package.
It’s the FSBrowser sketch, under File –> Examples –> Webserver.
In this video, I show you how to retrieve a file from the ESP32 using this sketch.