The Keyes USB Host Shield allows you to connect a USB device to your Arduino board. It is based on the MAX3421E , which is a USB peripheral/host controller containing the digital logic and analog circuitry necessary to implement a full-speed USB peripheral or a full-/low-speed host compliant to USB specification rev 2.0. This is based on revision 2.0 of USB Host Shield. it is compatible with more Arduinos – not only UNO and Duemilanove, but also Mega and Mega 2560 work with Standard variant of this shield out of the box. No more SPI re-wiring and code modifications – just solder included stackable connectors (2×3 ICSP connector’s female side should be facing down), plug and play!