Ubuntu wi-fi auto connect

I had 2 days of headache trying to make Beaglebone to connect to my wi-fi network upon startup. I installed ubuntu on it (oneiric 11.10). Currently it has only command line interface via serial.
Here is the solution how to configure it. My wi-fi network is open an has MAC connection control.

sudo apt-get install wpasupplicant

/etc/network/interfaces

auto wlan0
iface wlan0 inet dhcp
wpa-driver wext
wpa-conf /etc/wpa_supplicant.conf

/etc/wpa_supplicant.conf

ctrl_interface=/var/run/wpa_supplicant
network={
ssid="MyHomeNetwork"
scan_ssid=1
key_mgmt=NONE
}