Hi,

Do you know where I could find the implementation of the printf() function for the ATMega 168 chip? I am trying to understand how the FDEV_SETUP_STREAM() and uart_put/getchar() functions interact with it. I don't see how the FILE stream and charc c parameters in uart_putchar(char c, FILE stream) are passed.

Thanks.

Just search for "avr-lib source code" and you'll find it. It ends up calling vfprintf, which then makes multiple calls to putc, which just ends up calling uart_put or whatever other function is supplied when you create the stream structure.