Arduino Yun clone runs OpenWrt, offers Grove I/O
Feb 8, 2016 — by Eric Brown 4,893 viewsThe Arduino Yun- and Grove-compatible “Seeeduino Cloud” SBC has an AR9331 WiFi chipset that runs Linux via a Dragino HE COM, plus Ethernet and USB ports.
The Seeeduino Arduino clone from Seeed Studios has been around for years, adding three onboard Grove sensor interfaces to basic Arduino functionality. Now, Seeed Studios has launched a Seeeduino Cloud version that promises Arduino Yun compatibility, and which like the Yun, provides a Qualcomm Atheros AR9331 WiFi SoC running OpenWrt Linux on a MIPS processor.


Seeeduino Cloud, front (left) and back
(click images to enlarge)
According to Adafruit, where the new Seeeduino Cloud is available for $70, the Arduino Yun has been discontinued. The Yun, however, is still available for $75 at SparkFun among other places, and the newer, slimmed down Arduino Yun Mini can be found at online stores including Amazon, where it sells for $76.

Seeeduino Cloud with Dragino PA02 WiFi antenna
(click image to enlarge)
Like the Arduino Yun boards, the Seeeduino Cloud eases the interface between Arduino firmware and complex web services. It accomplishes this via a YunBridge library that delegates all network connections and processing of HTTP transactions to the Linux machine. “From the Arduino side it’s very easy to run commands on the Linux side and use it as an Ethernet and WiFi interface,” says Adafruit.

Dragino HE module
(click image to enlarge)
The Seeeduino Cloud is equipped with Dragino’s HE computer-on-module, which in turn supplies a MIPS 24Kc based, 400MHz Atheros AR9331 chipset with integrated 2.4GHz 802.11b/g/n WiFi. The HE module runs OpenWrt with the help of 64MB of RAM, and has 16MB flash, dual Ethernet controllers, and interfaces for USB host, UART, and 14x GPIOs. The module appears to come with a PA02 WiFi antenna, as shown in the images farther above.
The Seeeduino Cloud SBC adds a 16MHz ATmega32u4 microcontroller for Arduino compatibility, along with 32KB flash and 2.5KB SRAM. The board provides a 10/100 Ethernet port, USB host port, and a micro-USB port for power. Also available are 20x DIO pins, seven PWM channels, and 12 analog input channels, These interfaces provide compatibility with Grove shields for connecting the numerous Grove sensors and I/O daughtercards from Seeed Studios.


Seeeduino Cloud detail view (left) and block diagram
(click images to enlarge)
Other features include seven LEDs and three reset buttons for the MCU, the Linux system on the HE module, and WiFi. Schematics have been posted at Seeed Studio’s wiki.
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Back in October, Seeeduino Cloud was chosen by Amazon as one of its AWS IoT Starter Kit platforms. At the time, we assumed this was another MCU-only Seeeduino and lumped it with the other RTOS based kits. As it turns out, however, it can join the Linux-ready Starter Kits including Seeed Studio’s BeagleBone Green, Qualcomm’s DragonBoard 410c, and the Intel Edison.
Further information
The Seeeduino Cloud is available for $69.95 at Adafruit. More information may be found at Adafruit’s Seeeduino Cloud shopping page, and the Seeed Studios Seeeduino Cloud wiki
For similar specs, the LinkIt Smart 7688 Duo [1], also built by Seeed, looks like a much better value. At around $15 it offers:
* a 580MHz MIPS 24KEc CPU, 128MB RAM, 32 MB Flash
* an ATmega32u4, with Yun bridge or general Arduino IDE support
Grove and Arduino breakout boards are available at a pretty low cost .
[1] https://linuxgizmos.com/tiny-iot-sbc-runs-openwrt-on-mediatek-mips-soc/