WHAT ARE THE ADVANTAGES OF Arduino Uno R3 OVER Arduino Duemilanove IN AUTONOMOUS ROBOT FOR CONTROLLING RC SERVO MOTORS.
COMPANY STILL SELLING Duemilanove ?
Probably none, in real terms. The Uno is the current 'standard' model of Arduino, and R3 is the current interation of it.
BTW, there is no need to shout.
Not entirely... there are still plenty of Duimilinova's out there, in stock. (Still see plenty on EBay) no sense in tossing them out, just because there's the new UNO, unless the UNO gives drastic improvement to the design of a project.
Not saying there is no need to go with the UNO, but if the Duimilinova will do the job, why overlook it?
The main differences between the UNO and the Duemilanove are the USB to Serial interface. The Duemilanove uses an FT232 which only has the capability of turning your USB port on your computer into a serial port that is capable of talking to the Atmega328 (Arduino processor). The UNO replaces the FT232 with an actual microprocessor that has a real USB interface. The "stock" firmware on this processor make it act similar to the the FT232. It makes your USB port on your computer a serial port.
Now that you know the UNO has this microprocessor instead of a FT232 you may wonder why. The microprocessor has the capability to be reprogrammed and can change functions. Maybe you don't want it to be a USB->Serial adapter. You can program it to make the computer to think it is a keyboard, a mouse, or any other USB device. You can even use it as a second Arduino like device to offload processing from the main Arduino processor.
From what I have heard (do some research to verify this) the R3 has upgraded the USB microprocessor for one with more flash. It also has some extra shield pins to possibly prepare it for future shields that run or can't run on 3.3V I/O.
So how may all this concern your Autonomous Robot? Well that all depends on what you want to do. If you plan on having an onboard computer that need to interface to the USB of the Arduino for some reason other than serial data. You would want an Uno. If you need extra procession power and you want to take advantage of the extra processor on the Uno, than you want an Uno. If you don't have an Arduino, get an Uno R3 if you are looking for a Genuine Arduino. No reason to get an older model. If you don't think you will need those extra capabilities and also don't want a Genuine Arduino, take a look at all the Arduino derivatives that exist. You may find something that fits your needs better. Maybe something with built-in motor controllers or additional PWM outputs.
The UNO replaces the FT232 with an actual microprocessor that has a real USB interface.
It also requires a USB driver which appears at times to have issues that the FTDI driver doesn't.