The Mega 2560 is a microcontroller board based on the Atmega2560. It has 54 digital input/output pins (of which 15 can be used as PWM outputs), 16 analog inputs.
The Arduino ADK is a microcontroller board based on the ATmega2560 (datasheet). It has a USB host interface to connect with Android-based phones. It is compatible with Android’s Accessory Development Kit examples.
The Arduino Nano is a small, complete, and breadboard-friendly board based on the ATmega328 (Arduino Nano 3.x) orATmega168 (Arduino Nano 2.x). It has more or less the same functionality of the Arduino Duemilanove, but in a different package.
This 16 channel Servo/Pwm Shield is driven by just 2 I2C pins! When you want to control up to 16 servo motors without any wiring needed, this board is your answer.
This is a prototyping board, with copper pads. It is not continuous from one point to another You solder the components in place, and then simply cut pieces of wire, and solder them to make the circuit. It has a lot of holes
The ESP-8266EX-based Espressif development platform, almost compatible with the Arduino UNO pins, can also use some shield modules designed for the classic Arduino UNO.
This is a simple to use, USB to serial base unit for the XBee line. This unit works with all XBee modules including the Series 1 and Series 2.5, standard and Pro version.
