Overview;
The Arduino Yun is a microcontroller board based on the ATmega32u4 and the Atheros AR9331. The Atheros processor supports a Linux distribution based on OpenWrt named OpenWrt-Yun. 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.
The Arduino Yun is a microcontroller board based on the ATmega32u4 and the Atheros AR9331. The Atheros processor supports a Linux distribution based on OpenWrt named OpenWrt-Yun. 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.
Technical Specifications:
| Microcontroller | ATmegs32U4 |
| Operating Voltage | 5V |
| Input Voltage | 5v |
| Digital I/O Pins | 20 |
| Pwm Channel | 7 |
| Analog Input Pins | 12 |
| Flash Memory | 32 KB |
| SRAM | 2.5 KB |
| EEPROM | 1 KB |
| Clock Speed | 16 MHz |
OpenWrt-Yun
The Yun runs a distribution of Linux called OpenWrt-Yun, based on OpenWrt. While it's possible to configure the system from the command line, there is a web page that allows you to configure many of the different options available. The interface (called LuCi) gives you access to most any setting you would need for maintaining the WiFi interface.
Accessing the web interface is described below.
To install additional software on OpenWrt-Yun, you need to use the the Linux package manager opkg.
When interfacing with the OpenWrt-Yun system, you have to use a command line, either accessing it through the Arduino's Bridge library, or via SSH. If you are unfamiliar with the command line, you may want to read about some basics about it and some of the programs that are frequently used.
Python
An installation of Python 2.7 is included with OpenWrt-Yun, with which you can write applications or scripts.
External storage on the Yún
You can use external memory like a microSD card or thumb drive for saving data, or your own scripts, web pages, etc. For the Yún to access and store information on these drives through the 32U4, they need to have a directory named arduino in the root of the volume.
For additional information and documentation, refer
