These instructions assume that the wireless network is up and running:
$ iwconfig
Then to check that your hardware can see the wireless network you wish to connect to:
$ sudo iwlist scan
To receive your WiFi Key:
$ wpa_passphrase YOURSSID YOURWIFIPASSWORD
An example of the resulting text:
network={
ssid="YOURSSID"
.#psk="YOURWIFIPASSWORD"
psk=fe727aa8b64ac9b3f54c72432da14faed933ea511ecab1 5bbc6c52e7522f709a
}
Copy the "psk" to the /etc/network/interfaces where it reads wpa-psk.