Hardware Reference
In-Depth Information
Using such a device, the Pi can connect to a wide range of wireless networks, including those
running on the latest 802.11n high-speed standard. Before purchasing a USB wireless
adapter, check the following:
❍
Ensure that Linux is listed as a supported operating system. Some wireless adapters
are provided with drivers for Windows and OS X only, making them incompatible with
the Raspberry Pi. A list of Wi-Fi adapters known to work with the Raspberry Pi can be
found on the following website:
http://elinux.org/RPi_USB_Wi-Fi_
Adapters
.
❍
Ensure that your Wi-Fi network type is supported by the USB wireless adapter. The
network type will be listed in the specifications as a number followed by a letter. If your
network type is 802.11a, for example, an 802.11g wireless adapter won't work.
❍
Check the frequencies supported by the card. Some wireless network standards, like
802.11a, support more than one frequency. If a USB wireless adapter is designed to
work on a 2.4GHz network, it won't connect to a 5GHz network.
❍
Check the encryption type used by your wireless network. Most modern USB wireless
adapters support all forms of encryption, but if you're buying a second-hand or older
model, you may find it won't connect to your network. Common encryption types
include the outdated WEP and more modern WPA and WPA2.
Configuration of the wireless connection is done within Linux, so for now it's enough simply
to connect the adapter to the Pi (ideally through a powered USB hub). You'll learn how to
configure the connection in Chapter 5, “Network Configuration”.
Connecting Power
The Raspberry Pi is powered by the small
micro-USB
connector
found on the lower left side of
the circuit board. This connector is the same as is found on the majority of smartphones and
many tablet devices.
Many chargers designed for smartphones will work with the Raspberry Pi, but not all. The Pi
is more power-hungry than most micro-USB devices, and requires up to 700 mA of current
in order to operate. Some chargers can only supply up to 500 mA, causing intermittent prob-
lems in the Pi's operation (see Chapter 4, “Troubleshooting”).
Connecting the Pi to the USB port on a desktop or laptop computer is possible, but not rec-
ommended. As with smaller chargers, the USB ports on a computer can't provide the power
