AVR Power Conditioning

Question

So Im about to set up my first AVR MC experiment (the typical LED Blink) Im going to be ordering an ATmega328 and a Serial and Breadboard and such.

However i've heard it's a good idea to use some Capacitors to help smoothen out some specific lines.

I've "heard" it's a good idea to use smaller caps CLOSER to the Microcontroller, and then Larger caps near other components. is this true? And what kind (size) caps should I look for? Do I need these for every output pins, or just the VCC?

Thanks

Answer 1

Each supply pin (including AVdd) must be decoupled close to the pins, I use 100 nF on each one. A 10 uF is a good idea across the supply to the whole circuit. If you are using the ADC, the AVdd pin should have a filter; details are in the data sheet.

Answer 2

AVR has an app note exactly for this!

http://www.atmel.com/atmel/acrobat/doc2521.pdf

Advice on page 14 for layout considerations.