I have just done the same thing on Beagleboard_XM using OpenEmbeedded-core, Angstrom 2012.05 and Linux Kernel 3.2.18. Hopefully that’s similar to yourself.
It’s not clear if you are using an image downloaded from a website or if you have built it yourself, so again there might be some differences.
The default build that I initially made did not have the various kernel modules built into the kernel, so these needed to be loaded by hand. You can check by typing “lsmod” which lists the modules that have already been loaded.
Check to see if the ones below are in the list. If not then I load them with the following:
If you recheck with lsmod, you should now see these in the list.
I’ve also downloaded the RT2870_V22 firmware from the Ralink website and copied it into /lib/firmware.
For setting up the network security, you need to edit the wpa_supplicant.conf file in /etc and this will be specific to your network (So setup the SSID and any encryption key). Look for the “network” section in the file, it has lots of helpful comments.
Finally you might have to edit the /etc/network/interfaces file if you need to change from dhcp to static or similar.
Now when I type ifup wlan0 it discovers the network and starts working.
I found Jerrill’s blog most useful here, it takes you step by step through the problems that he encountered (which encouraged me because it isn’t a simple “do this and it works”).
It’s worth reading through (more than once).
One note, I then tried to build the kernel modules (*.ko) so that they were built into the linux kernel, but when you do that rfkill appears to have a widely reported issue. (Search rfkill on this forum). So I currently run with KO’s and load them with a script at startup.
I hope some of this helps.