前言：
树莓派有多种联网的方式，通过有线网或者通过无线网。通过有线网连接是比较简单的，在开启dhcp的路由器下，直接插上网线就可以联网，本文介绍树莓派无线联网的方式。再没联网的情况下，如果没有屏幕等外设，通过串口连接是一种比较简单有效的方式。
扫描WIFI:
使用如下命令可以扫描附近的无线网：
sudo iwlist wlan0 scan
扫描结果如下：
wlan0 ????Scan completed : ?????????Cell 01 - Address: F0:B4:29:1F:28:F1 ???????????????????ESSID:"00H Studio" ???????????????????Protocol:IEEE 802.11bgn ???????????????????Mode:Master ???????????????????Frequency:2.422 GHz (Channel 3) ???????????????????Encryption key:on ???????????????????Bit Rates:300 Mb/s ???????????????????Extra:rsn_ie=30140100000fac040100000fac040100000fac020000 ???????????????????IE: IEEE 802.11i/WPA2 Version 1 ???????????????????????Group Cipher : CCMP ???????????????????????Pairwise Ciphers (1) : CCMP ???????????????????????Authentication Suites (1) : PSK ???????????????????Quality=100/100 ?Signal level=84/100 ???????????Cell 02 - Address: 06:74:9C:08:3F:7C ???????????????????ESSID:"QLU-2.4G" ???????????????????Protocol:IEEE 802.11bgn ???????????????????Mode:Master ???????????????????Frequency:2.412 GHz (Channel 1) ???????????????????Encryption key:off ???????????????????Bit Rates:144 Mb/s ???????????????????Quality=100/100 ?Signal level=72/100 ???????????Cell 03 - Address: D6:50:3F:0B:81:D1 ???????????????????ESSID:"7788" ???????????????????Protocol:IEEE 802.11bgn ???????????????????Mode:Master ???????????????????Frequency:2.422 GHz (Channel 3) ???????????????????Encryption key:on ???????????????????Bit Rates:72 Mb/s ???????????????????Extra:rsn_ie=30140100000fac040100000fac040100000fac020c00 ???????????????????IE: IEEE 802.11i/WPA2 Version 1 ???????????????????????Group Cipher : CCMP ???????????????????????Pairwise Ciphers (1) : CCMP ???????????????????????Authentication Suites (1) : PSK ???????????????????IE: Unknown: DD180050F204104A00011010440001021049000600372A000120 ???????????????????Quality=44/100 ?Signal level=62/100 ?
这里的“00H Studio”是无线网的名称。IEEE 802.11i/WPA2 Version 1是加密的方式。加密的类型是WPA2类型的。
添加有密码的WIFI网络
通过配置wpa_supplicant.conf可以设置要连接的无线网。
sudo vim /etc/wpa_supplicant/wpa_supplicant.conf
在文件末尾出添加一下代码，并替换掉ssid_name以及password即可。
network={ ???????ssid="ssid_name" ???????key_mgmt=WPA-PSK ???????psk="password"}通过
ifconfig wlan0
可以查看IP地址是否分配成功
wlan0 ????Link encap:Ethernet ?HWaddr e8:4e:06:34:f8:f5 ???????????inet addr:192.168.9.177 ?Bcast:192.168.9.255 ?Mask:255.255.255.0 ?????????inet6 addr: fdf5:a28:b70c:0:746:52db:d822:14bd/64 Scope:Global ?????????inet6 addr: fdf5:a28:b70c::6c5/128 Scope:Global ?????????inet6 addr: fe80::ea4e:6ff:fe34:f8f5/64 Scope:Link ?????????inet6 addr: fdf5:a28:b70c:0:ea4e:6ff:fe34:f8f5/64 Scope:Global ?????????UP BROADCAST RUNNING MULTICAST ?MTU:1500 ?Metric:1 ?????????RX packets:100930 errors:0 dropped:36149 overruns:0 frame:0 ?????????TX packets:290150 errors:0 dropped:2 overruns:0 carrier:0 ?????????collisions:0 txqueuelen:1000 ??????????RX bytes:146598855 (139.8 MiB) ?TX bytes:3218776758 (2.9 GiB)
连接隐藏网络
如果要连接的是隐藏的网络，需要在配置文件中添加scan_ssid连接。需要添加的内容如下：
network={ ???ssid="yourHiddenSSID" ???scan_ssid=1 ???psk="Your_wifi_password"}添加多个无线网络配置
network={ ???ssid="SchoolNetworkSSID" ???psk="passwordSchool" ???id_str="school"}network={ ???ssid="HomeNetworkSSID" ???psk="passwordHome" ???id_str="home"}如果您有两个网络的范围，可以添加优先级选项来在它们之间进行选择。具有最高优先级的范围内的网络将是连接的网络。
network={ ???ssid="HomeOneSSID" ???psk="passwordOne" ???priority=1 ???id_str="homeOne"}network={ ???ssid="HomeTwoSSID" ???psk="passwordTwo" ???priority=2 ???id_str="homeTwo"}添加没有密码的WIFI网络
添加没有密码的WIFI网络需要注意将key_mgmt设置为NONE
network={ ???????ssid="ssid_name" ???????key_mgmt=NONE}IP的设置
auto wlan0iface wlan0 inet static ??address 192.168.0.1 ??netmask 255.255.255.0 wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
错误的调试
如果出现连接不成功的情况，有很大的可能是由于配置文件配置错误的原因。
sudo wpa_supplicant -c /etc/wpa_supplicant/wpa_supplicant.conf ?-i wlan0
通过wpa_supplicant的直接连接，如果配置文件出现问题，则会直接提示配置文件的错误详情。
如果出现一下结果，则一般代表配置文件没有问题
Successfully initialized wpa_supplicantnl80211: Driver does not support authentication/association or connect commandswlan0: Failed to initialize driver interface
树莓派Raspberry命令行配置无线网络连接
原文地址：http://www.cnblogs.com/shubin/p/7746399.html