Arduino Yún - Wi-Fi and Ethernet with it

The other day, an Italian company presented and launched sales of a new model in its device family - Arduino yún . The main highlight was what many Arduino fans have been waiting for a long time - built-in networking capabilities. Two network interfaces were added to the board at once - Wi-Fi and Ethernet.

The board itself is based on the Arduino Leonardo and is controlled by a combination of the ATMega32u4 microcontroller and the Atheros AR9331 SoC running Linino (Yún's Linux), a custom version of OpenWRT.

Interprocess communication

Yún's Linux and Arduino communicate through the Bridge library, which allows Arduino sketches to send commands to Linux. The processors themselves are connected by a serial interface, that is, ATMega32u4 works with Yún's Linux through the command line interface (CLI). It is also possible to install and run your Linux application using Bridge.

Another interesting feature is the ability to upload Arduino sketches through the WiFi interface via the So9 AR9331. If Arduino Yún is on the same network as the computer, the board will automatically detect in the Arduino IDE (a new version of the IDE has been released for this). The sketch will be transferred to AR9331 and Yún's Linux will flush the AVR microcontroller via SPI, acting as an AVR ISP programmer.

Networking features

Network access is implemented by two separate interfaces:
  • 10/100 Mbit / s Fast Ethernet
  • IEEE 802.11 b / g / n 2.4GHz WiFi supporting WEP, WPA and WPA2

The WiFi interface can also work in the access point mode. In the access point mode, other WiFi devices can connect directly to the Arduino Yún, however, unfortunately, in this mode, Internet connection is not possible, despite the presence of another network interface.
To simplify the work with popular Internet services, a partnership was signed with Temboo and the addition of the library of the same name in the Arduino SDK. This resource simplifies access to hundreds of popular web services acting as a proxy.


Arduino Yún can be powered by:
  1. micro usb
  2. Vin pins
  3. optional Power Over Ethernet (POE) module

Powering through the Vin pins can only be done by supplying 5V, because unlike other popular Arduino boards on Yún there is no voltage regulator.


As the operating system on the Atheros AR9331 SoC, the OpenWRT distribution of Linino is used. 16MB flash memory contains a Linux image, full python and a package manager. 64MB DDR2 should allow you to perform resource-intensive tasks, such as starting a web server or broadcasting video from a web camera. If necessary, the built-in 16MB memory can be expanded by using an SD card or USB Flash. To do this, you just need to create the arduino folder in the root of the card or flash drive and it will automatically be detected when connected.

USB host

Arduino Yún has a USB port connected to the AR9331 SoC. You can connect various peripherals to it: web cameras, data storage devices, various input devices, other devices, drivers for which are present in Linino. It is also possible to install drivers for specific devices. This USB port is not directly accessible from Arduino sketches.


69 $ / 52 €

Small presentation


Arduino fans should enjoy the device in the first place. And even despite quite serious competitors (Raspberry Pi, virt2real) I think Arduino Yún will succeed.


  1. Arduino yún
  2. It's time to enjoy the Arduino Yún: now available for purchase!
  3. Let's explore Arduino Yún's unique features - Hardware review