This shield adds USB Host functionality to popular Arduino platform.
The Arduino is a very popular platform, and it is only natural people start using it for ...strange... applications. Circuits@Home decided Arduino needed USB host functionality.
What's that mean? A standard Arduino is a slave device. You plug it into a computer, and the computer manages it by assigning it a COM port. This shield does the same sort of thing. Instead of plugging your USB keyboard into a computer, you can plug it into your Arduino!
This particular USB Host Shield is the “Minimal” configuration, which means which contains USB core components only. Unlike the "Simple" version, it is only compatible with 3.3V Arduinos, such as Arduino Pro (3.3V / 8MHz). Since no 5V is available, only communication with self-powered devices is possible. Additionally, not every self-powered device will work in this configuration. For unknown reasons, some external hard drives refused to answer until VBUS voltage was raised to 5V. On the other hand, all printers and digital cameras worked fine, as well as other types of external hard drives.
“Minimal” configuration is the best one for battery-powered projects since 3.3V Arduinos consume less electricity.
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