i'm building a device based on atmega168 and developed using arduino. it will communicate with a gsm module using rs232. i got some max3232 and i read resources about running the atmega168 standalone, and about interfacing it to a max3232.
when i found the page http://www.arduino.cc/en/Main/StandaloneAssembly i got confused: there the use of some inverters and a DB9 connector for the serial communication is shown.
I thought: it can't be used for usb connection, because i would need the ftdi chip, and also because inverters have ttl levels (0-3.3V), but it doesn't match rs232 specific, too...
so, what's the benefit of this configuration?