Archive for January 2013

Wifi on the Raspberry Pi using EDIMAX EW-7811Un and the 2012-12-16 wheezy raspbian image

The EDIMAX EW-7811Un is probably the most popular wifi adapter for the Raspberry Pi. It’s super tiny, doesn’t draw much power, and works (almost) out of the box with the latest Debian images (As of January 2013).

This, of course, doesn’t mean it’s easy to configure. I started off with this guide http://www.savagehomeautomation.com/projects/raspberry-pi-installing-the-edimax-ew-7811un-usb-wifi-adapte.html

But I have my own wpa_supplicant configuration.

Here is /etc/network/interfaces:

allow-hotplug wlan0
iface wlan0 inet manual
wpa-roam /etc/wpa_supplicant/wpa_supplicant.conf
iface default inet dhcp

And here is /etc/wpa_supplicant/wpa_supplicant.conf
This is for WPA and TKIP configuration since I could NOT get WPA2 to work.

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
network={
ssid="JOUB"
psk="MY_SECRET_PLAINTEXT_PASSWD"
proto=WPA
key_mgmt=WPA-PSK
pairwise=TKIP
group=TKIP
auth_alg=OPEN
}

if you’re seeing a message saying “WPA: IE in 3/4 msg does not match with IE in Beacon/ProbeResp”, you’re having authentication problems between WPA and WPA2. Be careful, you want ONE of the following:

WPA-PSK:

network={
ssid="my_network"
proto=WPA
key_mgmt=WPA-PSK
pairwise=TKIP
group=TKIP
psk="secret_password"
}

WPA2-Personal:

network={
ssid="my_network"
proto=RSN
key_mgmt=WPA-PSK
pairwise=CCMP TKIP
group=CCMP TKIP
psk="secret_password"
}