Is it workable to link a USB pendrive as an external storage device to the ESP or Uno R3?

Thread Starter


Joined Jul 16, 2022
I'm intending to save some .py files in the external storage on the usb pendrive, then read from it and process them on my esp8266, esp32, or uno R3. It does not have to be micropython, but rather a basic board that runs the C programming language. All I want is to connect an external storage device, such as a memory card or a pendrive. I would prefer to use micropython and a pendrive. ANyhting else transcending that would too work.


Joined Apr 11, 2010
There are SD card adapters that work for Arduinos and the like. I think you'd have to step up to something more like a Pi if you want support for USB drives.
Actually, the Arduino adapters are commonly for microSD cards. My laptop has an SD card slot and I use an microSD to SD Adapter to transfer files from my laptop to an Arduino.

Here is an SD card drive from Adafruit that works with an Arduino.

Jon Chandler

Joined Jun 12, 2008
The ESP32S2 version supports USB host mode and the use of USB thumb drives. Searching for "ESP32S2 USB thumb drive" will turn up several examples.

Note that the USB connector on NodeMCU modules is only a com port via a USB-UART adapter. To use USB host mode, a USB connector must be attached to the proper port pins.