Сторонние библиотеки

Коммуникации (сеть и протоколы):

Messenger - for processing text-based messages from the computer

NewSoftSerial - an improved version of the SoftwareSerial library

OneWire - control devices (from Dallas Semiconductor) that use the One Wire protocol.

PS2Keyboard - read characters from a PS2 keyboard.

Simple Message System - send messages between Arduino and the computer

SSerial2Mobile - send text messages or emails using a cell phone (via AT commands over software serial)

Webduino - extensible web server library (for use with the Arduino Ethernet Shield)

X10 - Sending X10 signals over AC power lines

XBee - for communicating with XBees in API mode

SerialControl - Remote control other Arduinos over a serial connection

Датчики:

Capacitive Sensing - turn two or more pins into capacitive sensors

Debounce - for reading noisy digital inputs (e.g. from buttons)

Дисплеи и светодиоды:

Improved LCD library fixes LCD initialization bugs in official Arduino LCD library

GLCD - graphics routines for LCD based on the KS0108 or equivalent chipset.

LedControl - for controlling LED matrices or seven-segment displays with a MAX7221 or MAX7219.

LedControl - an alternative to the Matrix library for driving multiple LEDs with Maxim chips.

LedDisplay - control of a HCMS-29xx scrolling LED display.

Генераторы частоты и Audio:

Tone - generate audio frequency square waves in the background on any microcontroller pin

Двигатели и ШИМ:

TLC5940 - 16 channel 12 bit PWM controller.

Время:

DateTime - a library for keeping track of the current date and time in software.

Metro - help you time actions at regular intervals

MsTimer2 - uses the timer 2 interrupt to trigger an action every N milliseconds.

Утилиты:

TextString aka String - handle strings

PString - a lightweight class for printing to buffers

Streaming - a method to simplify print statements