ESP32 Forum

Hi All,

I am kind of perplexed why I can't find example code for reading/writing data (.csv) to a usb flash drive. There are plenty examples on how to do this with a SD card, but nothing for a simple usb flash drive. I have also found examples on how to make the ESP32 appear as a mass storage device, but not how to access one itself?

The USB interface is pretty slow (Full Speed), and USB flash is more expensive than a microSD, so I wouldn't recommend it generally.
https://github.com/espressif/esp-idf/tr ... b/host/msc

Unfortunately that isn't Arduino IDE compatible code, which is what I was looking for.

All I would like to do is read/write sensor data to a log file. Adding a SD means buying and mounting the breakout board, tying up more GPIO, and having to find a SD card reader if I ever want to check/change the data.

I do have the device setup to upload this data to an Amazon DB, but hoping to be able to plug in a small usb stick to read/write this data for redundancy. Also we are much more likely to loose Wifi than electric, and logging data during those periods would be preferred.