WLAN devices in Linux
WLAN devices (or Wi-Fi) are usually identified in the GNU/Linux system with wlan0, wlan1, and so on, and they can be added to an existing system in several ways. The Wandboard comes with its own Wi-Fi chip but it's quite common (especially for cost reasons) that an embedded computer has no Wi-Fi at all. So, in this case, we can provide a wireless connection to our embedded kit using an available CPU's communication bus, such as the USB bus and (sometimes) the SDIO or SPI bus.
Pluggable external WLAN devices
As a simple example, in the following image, there is a picture of a USB WLAN device that can be connected with every computer that has a USB host port:
Note
The device can be purchased at: http://www.cosino.io/product/usb-realtek-wifi-adapter or by surfing the Internet.
If we try to connect one of these devices to our host PC, we should get following kernel messages:
usb 2-1.1: new high-speed USB device number 13 using ehci-pci usb 2-1.1: New USB device...
