USART - serial communication (Universal Synchronous/Asynchronous Receiver/Transmitter)

• Introduction to microcontroller USART

A very nice and simple explenation of what USART is and how it can be utilized with microcontrollers for robotics projects.

• AVR USART implementation in C code

Again a very nice and simple explanation of the implementation UART functionality to your robotics project

• Using the USART with AVR-GCC
  

This is a great tutorial on USART - serial communication for AVR microprocessors, contains well explained code and other users feedback. It is from the AVR Freaks website.

• Using the USART - Interrupt driven serial comms

This page is an extension on the above tutorial, it covers interrupts