The launch
Arduino YÚN (which means “cloud” in Chinese) is announced at Maker Faire Bay Area 2013 and released on 10 May 2013. It is the first official Arduino board to integrate Linux on the same PCB as a classic Arduino microcontroller.
Dual-chip architecture
YÚN hosts two chips communicating via internal serial:
- ATmega32U4 — AVR microcontroller at 16 MHz, pin-compatible with Arduino Leonardo (standard Arduino sketches)
- Atheros AR9331 — MIPS SoC at 400 MHz with Wi-Fi 802.11n, Ethernet, USB host, 64 MB DDR2 RAM, 16 MB flash
On the AR9331 runs Linino, a Linux distribution based on OpenWrt (the open source router firmware). The microcontroller handles GPIO pins and realtime sensor/actuator interaction; Linino handles network, file system, cloud communication, Python/Lua scripts.
Bridge Library
The software bridge between the two chips is the Bridge library: Arduino API that sends commands to the Linino side, which can:
- Run shell commands via
Process - Read/write files on storage via
FileIO - Make HTTP REST calls via
HttpClient - Publish to Temboo (API integration service)
- Print via attached USB printer
This turns a simple Arduino into an IoT gateway connected to the Internet without complex firmware code.
Use cases
YÚN is explicitly designed for:
- IoT sensing — publishing data to the cloud via HTTP/MQTT
- Home automation — home control with web interface
- Small web servers — local Wi-Fi dashboard
- Physical-digital bridge — remote control of physical devices
- Educational IoT — advanced school courses requiring connectivity
Limits and successors
YÚN has a high cost (~€70 at launch) and requires Linux knowledge not always present in classic Arduino makers. It is surpassed by:
- Arduino YÚN Mini (2016) — compact version
- Arduino MKR1000 (2016) — WiFi + integrated cryptography, no Linux
- Arduino MKR WAN 1300 (2017) — LoRaWAN
- ESP8266 / ESP32 (third parties, 2014+) — much cheaper and more popular
- Raspberry Pi with GPIO + Arduino via USB — alternative pattern
In the Italian context
YÚN was for many Italian technical institutes and universities the first structured academic IoT experience. It inspired many thesis projects (2013-2016) on sensor networks, home automation, prototype telemedicine. At noze, YÚN was used as a fast gateway for telemetry PoCs and digital health prototypes before converging on ESP32 + edge Linux.
References: Arduino YÚN (10 May 2013). Dual-chip ATmega32U4 + Atheros AR9331. Linino on OpenWrt. Bridge library. Temboo integration. Wi-Fi 802.11n, Ethernet. Successors: YÚN Mini, MKR1000, MKR WAN 1300.