This will publish data from iwlist scanning on a topic (published every 5 seconds, hard-coded at the moment). Simply run as rosrun wifiscanner wifiscanner.py.

Parameters:

• ~iface: setting the interface to scan, defaul is wlan0
• ~ssid: defines the ESSID to scan for, default STRANDS

For this to work, one needs to be able to run this command: sudo iwlist %s scanning, so run sudo visudo and edit the sudoers:

%sudo ALL=NOPASSWD: /sbin/iwlist