In this tutorial, you will learn how to get your Arduino Yun up and running so that you can run example sketches made for the Yun. In this case, I will show you how to run the WiFiStatus example. Let's get started!
Step 1: Download the Arduino 1.5.6-r2 Beta IDE
The Arduino Yun requires a special version of the Arduino IDE in order for it to be a recognized board. You can download it where you download the main Arduino IDE here: http://arduino.cc/en/Main/Software
Step 2: Change Your Wifi Network to the One Produced by the Yun
If you are using a Mac, click on the wifi icon in the top right of your screen (near the volume icon). Here, you should see a new wifi network emitted by the Yun. It should look something like "Arduino Yun-90A2DAF00BF0". Choose this network. If you do not see this network, hold the restart button on the Yun near the USB port for over 5 seconds to restart its wifi emission. If it still does not show up, hold the restart button for over 30 seconds to restart its built-in Linux processor. For more information on this step, check out http://arduino.cc/en/Guide/ArduinoYun.
Step 3: Browse to Http://arduino.local/ and Enter Arduino for Your Password
Once you are connected to the wifi network provided by the Yun, open your web browser and type in the URL "arduino.local". Once there, it will require you to type in a password. The password that comes with every Yun is "arduino". If it states that this password is incorrect, then your Yun has already been configured with another password by someone else who previously used it.
Step 4: Configure Your Yun
After inputing your password, you should arrive at a page that displays connection details about your Yun. Click on the "Configure" button on the top-right corner of the page. Once you are on the configuration page, change your password to whatever 8 character word you like, and make sure to select your wireless network (not the one emitted by the Yun) where it says "Detected Wireless Networks". Your wireless network name should appear underneath it once it is selected. Match the security drop-down with your wireless network security (most wifi networks with passwords are WPA2). If your wireless network requires a password, type it in the last form field. Once configured, you should see a loading bar that indicates how long it will take for the new information to configure and restart your Yun.
Step 5: Running an Example With Arduino Yun
Now you are ready to run example sketches with your Arduino Yun. Open the Arduino Beta IDE that you downloaded at the beginning of this tutorial, and navigate to File > Examples > Bridge > WiFiStatus. Click on the WifiStatus sketch. Before running the sketch, make sure you have the Arduino Yun selected under Tools > Board. Also, make sure that you are connected to your regular wifi, and not the one emitted by the Yun. Finally, select the port that your Yun is connected to under Tools > Port (mine is /dev/tty.usbmodem1411 (Arduino Yun). Once you have completed all of this, upload the sketch to your Arduino and click on Tools > Serial Monitor to track your wifi status. That's all! At this point, you should be able to run any example within the Bridge directory, such as TimeCheck, YunSerialTerminal, etc.