If the Arduino Yun is set to your home WI-FI and you want to bring it to another WI-FI spot to use ( friends house , school etc...) would it just pick up the connection and you just normally put in the password or network key. Or you have to register each time a new Wi-Fi spot ?
The Yun does not remember wifi settings, it would be a security risk. You have to register to the target wifi each time
Just like Federico said, Yun only hold one STA setting. However since Yun is linux you could code it yourself.
Re: List of access points and signal strength
http://forum.arduino.cc/index.php?topic=220440.msg1604651#msg1604651
iwlist wlan0 scan |grep 'Channel:\|Quality\|ESSID'
iwlist wlan0 scan |grep 'ESSID'
automatically to a Wi-fi connection?
http://forum.arduino.cc/index.php?topic=216850.msg1586874#msg1586874
last one is
/usr/bin/wifi-live-or-reset
cp /usr/bin/wifi-live-or-reset /usr/bin/wifi-live-or-switch
change code by combine above from reset to switch.