If you don't do a normal install of avrdude and instead download the a zipped file directly. 

Open a terminal and type: echo -e $PATH         [typical response is]

/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games:/sbin:/usr/sbin 

To allow avrdude to launch from anywhere:

You can place "avrdude and avrdude.conf" in the /usr/local/bin.  [obviously root access is needed]

Make sure thas avrdude file permissions have been set to "Allow file to run as a program", it normally is. 

Either way, verify access by:  

Open a terminal from the desktop and type avrdude, you should see help on how to use the command line options.

If avrdude in not in the path it will error.
