Arduino.org Yún Microcontroller Board
Arduino.org Yún Microcontroller Board is the first stand-alone Arduino featuring built-in Ethernet and WiFi support, removing the need for a board as well as a WiFi shield. It is based on the Atmel ATmega32u4 and the Atheros AR9331. The Atheros processor supports a Linux distribution based on OpenWRT named Linino. The board has built-in Ethernet and WiFi support, a USB-A port, micro-SD card slot, 20 digital input/output pins (of which 7 can be used as PWM outputs and 12 as analog inputs), a 16MHz crystal oscillator, a micro USB connection, an ICSP header, and a 3 reset buttons. The Yún distinguishes itself from other Arduino boards in that it can communicate with the Linux distribution onboard, offering a powerful networked computer with the ease of Arduino. In addition to Linux commands like cURL, users can write their own shell and python scripts for robust interactions. The Yún has built-in USB communication, eliminating the need for a secondary processor. This allows the Yún to appear to a connected computer as a mouse and keyboard, in addition to a virtual (CDC) serial / COM port.