The code for the fading LED is written in C with the WINAVR C-Compiler. In this example the LEDs will fade in and out one by one. The PWM timers of the ATTiny2313 are used to let the LED's fade in and out. To use the PWM timers you first need to initialize the timers at the begin of the program code. The speed of the fading in and out can be changed with changing the clock speed of the ATTiny2313. You can copy and paste the textfile into the WINAVR C-compiler. Below you can download the C code and the hex file.