The Arduino Yún is a microcontroller board based on the 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 16 MHz
crystal oscillator, a micro USB connection, an ICSP header, and a 3 reset buttons.