Now it's time to take a look at Universal Serial Bus (USB), a versatile bus widely used in modern PCs that allows people to connect an electronic device to a computer, for instance, a hard disk, a keyboard, or a serial device (as seen in the previous chapter) can all be connected to a computer through the same USB port.

After a brief introduction about what this bus is and how it works, we'll show you the different types of USB devices and how they are supported in the BeagleBone Black's kernel. The BeagleBone Black can act as a USB host in order to manage a barcode reader; then we will see how we can use the BeagleBone Black as a USB device in order to exchange data with a host PC.