The first thing I did when I got my Raspberry Pi was to buy a wifi dongle for it so that I could put it anywhere in the house without the need for a wired connection. For this purpose I bought the Edimax EW-7811Un 802.11n wifi dongle. It was cheap and the docs said it was supported so I bought it. Tonight I finally had a chance to set up the wifi dongle and I thought I’d share my process and tips for setting it up.
I spent at least an hour trying to set up my wifi dongle before I realized that my biggest problem was the version of Raspbian Wheezy that I had imaged on my 4GM SD card. I got the card at PyCon 2013 and have had a few issues with it that I’d just dealt with. I decided it made more sense to just re-image the card and that fixed almost all of my up-front problems. You can get the lastest Raspbian Wheezy image from the Raspberry Pi Downloads page. If, like me, you’re on OSX then you can use the OSX Installer script that I’ve linked to.
Before you go any further make sure that your dongle is recognized by your system with commands lsusb and lsmod.
I started setting up the wifi dongle using a great Wifi Tutorial from Adafruit. I highly recommend following along there and she has lots of other available resources. For me that got me started but I needed a few more things to get going. Also, there shouldn’t be any need to restart your RPi if you follow these instructions. Generally if you have to restart a linux box you’re probably doing something wrong. There’s always a command to get things going or to reset things.
The first file to set up is /etc/network/interfaces:
auto lo
iface lo inet loopback
iface eth0 inet dhcp
allow-hotplug wlan0
iface wlan0 inet manual
wpa-roam /etc/wpa_supplicant/wpa_supplicant.conf
iface default inet dhcp
The second file to set up is /etc/wpa_supplicant/wpa_supplicant.conf
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
ap_scan=1
network={
scan_ssid=1
key_mgmt=WPA-PSK
proto=RSN WPA
pairwise=CCMP TKIP
group=CCMP TKIP
ssid="YOUR-NETWORK-SSID"
#psk="YOUR-NETWORK-PASSWORD"
psk=YOUR-UNQUOTED-HASHED-NETWORK-PASSWORD
}
The second file was harder to set up without help. You should be able to get started with this command:
$ sudo wpa_passphrase YOUR-NETWORK-SSID YOUR-NETWORK-PASSWORD > /etc/wpa_supplicant/wpa_supplicant.conf
This creates the last three lines of your network. Then you can fill in the remaining lines using:
$ sudo nano /etc/wpa_supplicant/wpa_supplicant.conf
With these files set up all you have to do is restart the network and test that your configuration works:
$ ifconfig wlan0
$ iwconfig wlan0
$ sudo iwlist wlan0 scan
$ sudo ifdown wlan0; sudo ifup wlan0
$ sudo dhclient wlan0
$ sudo iwconfig wlan0 essid YOUR-NETWORK-SSID
$ ifconfig
$ sudo apt-get update
You should see an assigned ip address in the ifconfig step and the apt-get update should work without any errors. Now you’re all set up!