Arduino YÚN (Arduino Leonardo + Wifi system-on-a-chip Linino) A000008 (643042)

The Arduino Yún is a microcontroller board based on the ATmega32u4 (datasheet) and the Atheros AR9331. The Atheros processor supports a Linux distribution based on OpenWRT named Linino. The board has built-in Ethernet and WiFisupport, 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.

 

 

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, you can write your own shell and python scripts for robust interactions.

 

The Yún is similar to the Leonardo in that the ATmega32u4 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.

 

 

The Bridge library facilitates communication between the two processors, giving Arduino sketches the ability to run shell scripts, communicate with network interfaces, and receive information from the AR9331 processor. The USB host, network interfaces and SD card are not connected to the 32U4, but the AR9331, and the Bridge library also enables the Arduino to interface with those peripherals.

 

Summary

Because the Yún has two processors, the summary section shows the characteristics of each one in two separate tables.

 

AVR Arduino microcontroller
Microcontroller	ATmega32u4
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
Linux microprocessor
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	16 MB
PoE compatible 802.3af card support