USB Host Shield For Arduino Pro Mini 3.3V - (AD42220)

Description:

This shield is based on the MAX3421E, which functions as a USB host (computer ports operate in this mode). It fits the Arduino Pro Mini 3.3V @ 8 MHz. After soldering together (as seen in the second image) it is slightly larger than the Arduino Pro Mini itself. It can act as a breakout for a generic USB host (with any microcontroller working with 3.3V logic or with a proper level shifter). It does not work when soldered onto an Arduino Pro Mini 5V @ 16 MHz. Moreover, it will be damaged, so don't do it!

This is only the Mini USB Host shield (no Arduino Pro Mini, you must purchase it separately).

Reference link