Arduino YÚN is the first member of a new groundbreaking line of wifi products combining the power Linux with ease of use of Arduino.
The first Arduino YÚN is the combination of a classic Arduino Leonardo (based on the Atmega32U4 processor) with a Wifi system-ona-chip running Linino (a MIPS GNU/Linux based on OpenWRT). We embedded the Linux machine directly on the PCB of the Arduino Leonardo and we connected the two so that from Arduino it’s very easy to run commands on the Linux side and use it as an Ethernet and Wifi interface.
AVR Arduino microcontroller
Operating Voltage 5V
Input Voltage 5V
Digital I/O Pins 20
PWM Channels 7
Analog Input Channels 12
DC Current per I/O Pin 40 mA
DC Current for 3.3V Pin 50 mA
Flash Memory 32 KB (of which 4 KB used by bootloader)
SRAM 2.5 KB
EEPROM 1 KB
Clock Speed 16 MHz
Processor Atheros AR9331
Architecture MIPS @400MHz
Operating Voltage 3.3V
Ethernet IEEE 802.3 10/100Mbit/s
WiFi IEEE 802.11b/g/n
USB Type-A 2.0 Host/Device
Card Reader Micro-SD only
RAM 64 MB DDR2
Flash Memory 32 MB
PoE compatible 802.3af card support
It is recommended to power the board via the micro-USB connection with 5VDC.
If you are powering the board though the Vin pin, you must supply a regulated 5VDC. There is no on-board voltage regulator for higher voltages, which will damage the board.
The Yún is also compatible with PoE power supply but in order to use this feature you need to mount a PoE module on the board or buy a preassembled board.
Early models of the Yún with a PoE adapter were incorrectly providing the board with 12V. An updated version will soon be provided to distributors that provide the expected 5V. If you believe you have the wrong PoE adapter on your board.
The power pins are as follows:
VIN. The input voltage to the Arduino board. Unlike other Arduino boards, if you are going to provide power to the board through this pin, you must provide a regulated 5V.
5V. The power supply used to power the microcontrollers and other components on the board. This can come either from VIN or be supplied by USB.
3V3. A 3.3 volt supply generated by the on-board regulator. Maximum current draw is 50 mA.
GND. Ground pins.
IOREF. The voltage at which the i/o pins of the board are operating (i.e. VCC for the board). This is 5V on the Yún.
The ATmega32u4 has 32 KB (with 4 KB used for the bootloader). It also has 2.5 KB of SRAM and 1 KB of EEPROM (which can be read and written with the EEPROM library).
The memory on the AR9331 is not embedded inside the processor. The RAM and the storage memory are externally connected. The Yún has 64 MB of DDR2 RAM and 16 MB of flash memory. The flash memory is preloaded in factory with a Linux distribution based on OpenWRT called Linino. You can change the content of the factory image, such as when you install a program or when you change a configuration file. You can return to the factory configuration by pressing the “WLAN RST” button for 30 seconds.