A weblog focused on interesting circuits, ideas, schematics and other information about microelectronics and microcontrollers.
SimAVR - free open source AVR simulator
"Small, mean and lean hackable AVR simulator".
simavr is a new AVR simulator for linux, or any platform that uses avr-gcc (you can try the Cygwin/MinGW). It uses avr-gcc own register definition to simplify creating new targets for supported AVR devices.
+ IO ports (including pin interupts)
+ 8 bits timers (well, CTC and Fast PWM, the overflow interrupt too)
+ The UART, including tx & rx interrupts (there is a loopback/local echo test mode too)
+ SPI, master/slave including the interrupt
+ External Interupts, INT0 and so on.
Read more & download: