Hi Nandika,
How are you doing? I couldn't login during day time today and I suspect that you have added some questions in DigitalSriLanka group. I really like that group.
Okay. With regard to your question... Arduinos are Atmel based. So you need to switch to Atmel to do those. There are two methods to work with Arduino.
1. Using Arduino IDE
This is a multi-platform IDE with a 'C like' language which uses AVR-gcc libraries internally to compile codes.
One of the advantageous of using Arduino IDE is that you can directly program the unit using USB port. Otherwise you will need a programmer with an IcSP interface.
2. Using AVR Studio and AVR-gcc C compiler
To use this, you will need an IcSP programmer such as the one below. You can avoid using the bootloader (which is required to use Arduino IDE) and directly use the chip as you are doing with PICs at the moment.
If you are good in programming, I would like to recommend you the 2nd method. But if you are not, it will be helpful for you may go on with the first as there are so much coding support around the net.
Before moving to hardware, have a deep look at the official page
http://www.arduino.cc/en/Main/ArduinoBoardDuemilanove. It says what you have on board.
Have a look at this article on motor control.
http://www.barnesian.com/2011/05/arduin ... oller.html
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