Hello !
So I am starting scratch the surface of the Embedded systems world. I have always wondered how to interface a microcontroller like the AVR for example with a USB stick to read the file names for example or the space left or even format/delete files from the USB stick without using any PC(computers). Is that possible by connecting a USB port to the AVR and by some programming can do such application and how?? or what does it need to do such application with a microcontroller??
Thanks in Advance!

 

Everything is doable but the issue with a USB stick is that the USB gets in the way. There are examples of USB host code for some MCUs and conceptually all you need is a socket and host controller though to be fully USB compliant you need to source 500mA @ 5v to power the USB device which could be problematic on some installations.

Here is a USB Host 'shield'
and libraries here.


A much simpler solution, and one I use a lot, is to write to a micro-SD card and then use an USB SD-card adapter...

 

Have a look at post #5 in this very old thread.
https://www.avrfreaks.net/forum/how-can-i-read-usb-flash-drive-avr

You might want to check the Microchip site for application notes and code using USB OTG (USB On The Go) on more modern controllers.

 

SD cards are a lot easier. You can read them through the SPI port, and the FAT32 filing system isn’t difficult to deal with.
Many microcontrollers that have USB ports can only be slaves, but you need it to be master to read a USB memory stick.

 

https://www.microchip.com/sitesearch/search/All/usb otg

http://shieldlist.org/sparkfun/usbhosthttp://shieldlist.org/sparkfun/usbhost

http://circuitsathome.com/arduino_usb_host_shield_projects/