AVR数字通用IO,一张很不错的图，显示了AVR IO的内部结构-AVR digital general purpose IO, a very good map, shows the AVR IO internal structure

avrusbd，AVR单片机IO摸拟USB与电脑通讯- THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR

Code of AVR PORT control led and speaker

Basic Interrupts and I/O Eivind, AVRfreaks.net, Oct.2002 Lets' get physical The natural place to start is the STK500. It is a very nice development board for the AVR, reasonably priced (~USD79) and provides all the environment we need to test s