I would like to completely uninstall ros indigo from my system and remove all things related to it. There are several questions about this topic but they are all related to Ubuntu OS. I'm using Raspbian.

Thanks.

EDIT:

I've installed ROS using the steps provided by the official guide @ this link. I can't find any ros-* package installed in the system. I've used only python modules during the installation.

sudo apt-get purge ros-*
Package 'ros-groovy-roscpp-core' is not installed, so not removed
[...]
Package 'ros-hydro-visualization-msgs' is not installed, so not removed
Package 'ros-hydro-xmlrpcpp' is not installed, so not removed
The following packages will be REMOVED:
  firmware-atheros*
0 upgraded, 0 newly installed, 1 to remove and 64 not upgraded.
After this operation, 834 kB disk space will be freed.
Do you want to continue [Y/n]? Y
(Reading database ... 84843 files and directories currently installed.)
Removing firmware-atheros ...