Arduino Internals

Serial Interface

The serial interface of the Arduino survives functionally intact from the very earliest prototypes until today. A good case can be made for the argument that the serial bootloader arrangement defines the Arduino development methodology, separating it from bare-metal embedded development.

There are, in fact, several distinct serial interfaces available on the modern Arduino, thanks to the wide variety of peripherals offered by the Atmel AVR processor. The most famous serial port in the Arduino world is the Universal Synchronous/Asynchronous Receiver/Transmitter (USART) peripheral, which sends or receives data over a single wire asynchronously (one wire for each data direction, plus a ground reference connection) at a predetermined ...