USB wifi for Raspberry Pi

Here are steps for setting up the USB wifi adapter TP-LINK TL-WN722N on my Raspberry Pi:

• Edit /etc/apt/sources.list and add deb http://ftp.us.debian.org/debian squeeze non-free at the end



• sudo aptitude update




• sudo aptitude install firmware-atheros



• Download the firmware
  

  cd /lib/firmware
  sudo wget http://linuxwireless.org/download/htc_fw/1.3/htc_9271.fw



• Protect the file /etc/network/interfaces
  

  sudo chmod 0600 /etc/network/interfaces



• Edit /etc/network/interfaces
  

  sudo vi /etc/network/interfaces



• Add the following lines. Note that I am using WEP. If you are using WPA, use the fields wpa-ssid and wpa-psk instead
  

  auto wlan0
  allow-hotplug wlan0
  iface wlan0 inet dhcp
          wireless-essid your-ssid
          wireless-key your-hex-key



• Bring up the interface
  

  sudo ifup wlan0

About the performance. Using sftp to copy /dev/zero via wifi maxed out the CPU with transfer rate at around 1.6MB/s... maybe need to test the speed without encryption...

Reference: http://elinux.org/RPi_VerifiedPeripherals#Working_USB_Wifi_Adapters