On Arduino.cc You can always find and download most recent Arduino YUN system image (firmware). What to do, if You need older one?
Older firmware for Arduino YUN
First, You need to know which firmware You need. Browse all release notes on GitHub. Knowing which one You need, insert revision number into link replacing
So, if You need 1.4.2 link for download is:
And for Release 1.3:
Arduino YUN is very powerful tool especially with data acquisition services like ThingSpeak. Today we had urgent need to get some data from sensors, and running simple sketch and making data available through ThingSpeak was a breeze:
Arduino YUN is very interesting product. Mixing OpenWRT and Arduino in one board is effective. OpenWRT does things related to WiFi connectivity, Arduino YUN does interact with physical world, and standard Arduino library makes connecting both parts easy. Now we need some simple project to demonstrate how You can control things remotely with Arduino YUN
Arduino YUN allow You control physical elements with smartphone or other browser.
To demonstrate how easy You can build something using this components we will use Arduino YUN, connect to it with browser (can be in smartphone) and You control some LED using webpage. This project was shown on Robomaticon 2014 in Warsaw to make YUN more understandable. Robomaticon is event for robotics and electronics enthusiasts, so YUN was acting as open hot spot, anybody could connect to it and using http://188.8.131.52 control LEDs. Why numerical address instead of some more userfriendly name distributed via DHCP to clients? Not all phones were accepting .local domain extension, so since whole setup was not connected to Internet we used this easy to enter public address.