Arduino has launched the Arduino Yun Rev 2, a rev of the original OpenWrt-driven Arduino board with enhanced LAN, USB, security, and power supply features.

Just when we thought we had seen the last of the Linux-enabled Arduino boards, Arduino has updated the very first such SBC: the WiFi-enabled Arduino Yun (or Arduino Yún), which launched back in 2013. The Arduino Yun Rev 2 makes only minor alterations to the original, which went out of stock last year. As reported by Electronics Weekly, the Yun 2 is now available for 42.99 Pounds ($57) excluding VAT at RS Components, with shipments due in mid-August.

Arduino Yun Rev 2 (left) and original Yun
(click images to enlarge)

The original design inspired the now defunct Arduino Yun Mini in 2015. There was also the Arduino Yun Shield add-on to standard Arduino boards and Seeed’s “Seeeduino Cloud pseudo clone, both of which shipped in 2016.

Back in 2013, the OpenWrt-on-Atheros design was the cheapest way to add WiFi to an Arduino board. After the original shipped, Arduino forked into two projects. The forked Arduino Srl unit pushed out several Linux-based Arduino boards including the Arduino Tian and Arduino Industrial 101. Since the projects have reunited, however, these products have faded away.

The new Arduino models, such as the FPGA-enabled MKR Vidor 4000 do not run Linux, which is no longer necessary to run WiFi now that Arduino-compatible wireless modules based on the ESP32 SoC and other chips are readily available. For example, the ESP32 based u-blox Nina W102 module supplies WiFi to the MKR Vidor 4000 and Uno WiFi Rev 2.

Arduino Yun Rev 2, front and back
(click images to enlarge)

In the Arduino Yun Rev 2 announcement in late March, Arduino co-founder Massimo Banzi wrote that the Yun had been used in “hundreds of thousands of projects and professional applications.” He also had this to say: “The Yùn enjoyed tremendous success; however, it ended up being affected by the internal issues we dealt with over the past couple of years and support has been quite intermittent. For example, the board was never really an open-source product and the software had some challenges that we wanted to fix, especially from a security point of view.”

When referring to security, Banzi appears to be speaking of the new Secure Sockets Layer (SSL) support that has been added to the Bridge software, which mediates between the Arduino and Linux computers on the board. It’s unclear, however, what kept the board from being fully open source or whether those issues have been resolved. The Qualcomm Atheros AR9331, which powers all the Yun models, is generally considered to be an open source friendly design.

The SBC has been updated to the latest version of the lightweight, router-oriented OpenWrt Linux distribution, which should also improve security. The first-gen Yun and Yun Mini ran on an Arduino friendly variation of the open source OpenWrt called Linino. OpenWrt, by the way, has survived its own fork, and the OpenWrt and LEDE projects have been reunited.

The Arduino Yun 2 is equipped with the same MIPS-based, 400MHz Atheros AR9331 WiFi SoC, 64MB of DDR2 RAM, and 16MB of flash found on the Rev 1. The AR3991 chip’s built-in WiFi continues to be 2.4GHz 802.11b/g/n. Like its predecessor, the new model also offers a 16MHz Atmel ATmega32U4 chip running Arduino code, with 2.5KB RAM, 32KB flash, 20x DIO pins, 12x analog outputs, and 7x PWM interfaces.

The board is once again equipped with an Ethernet port, USB host port, and microSD slot. However, the 10/100 Ethernet port has been switched to a new model that avoids accidental short circuits when using certain Arduino shields. The USB hub has also been improved, and the USB port has been flipped from vertical to horizontal to make for a more compact profile.

A micro-USB client port is used for a power input to the “much better, more robust power supply,” and and 4x LEDs are available. The board appears to have the same 73 x 53mm dimensions as the original.

 
Further information

The Arduino Yun Rev 2 is available for 42.99 Pounds ($57) excluding VAT at RS Components, with shipments due in mid-August. More information may be found at the Arduino Yun Rev 2 shopping page.