I working on my first PCB eagle file and am confused. In the attached image, on the left is a pin out for the ATMega168 (same pin out as 328). On the right is a 28 pin socket for the ATMega.

I don't understand how the pins on the ATMega related to the socket. I was expecting 14 or less on each side.

Thanks!

 

If you search on "atmega 128", it appears that it comes in a 64 pin package - http://www.atmel.com/dyn/products/product_card.asp?part_id=2018

 

Looks like a 32 pin package. That is 16 pins per side. The schematic symbol can be made anyway you want. Someone has just created it to suit there needs.

 

I see that 328" is a bit different from "128".

 

The 168/328 comes in several different packages:

MLF (VQFN) 32
PDIP 28
TQFP 32

One package has 28 pins and the others have 32 pins. The model decal shown above has 32 pins and is not what you want if you are using the 28 pin DIP package. You may have to make a new decal for the schematic if you can not find one online...