When you start the EV3 with a leJOS SD card in the card reader, the Start-up Menu Java program runs automatically:
The first screen you see is the Run Default screen:
There are a set of top-level menu items that you navigate between using the Left and Right keys. To select a menu item press Enter. To go back to the top-level menu screen, press the Escape key. When a top-level screen is displayed, Escape will prompt you to shut down the EV3.
As well as showing a specific menu item (such as Run Default), the menu also displays your EV£ name (default "EV3"), the battery level and the IP addresses of the device. The top IP address is used for USB and Bluetooth connections, and the bottom one (if present), for Wifi connections.
The Run Default Screen:
Pressing ENTER on the Run Default screen will run your default program if you have one. See below for how to select a default program. If there is no default program a message saying "No default set" will be displayed for a few seconds.
The Files Screen:
When you press ENTER when the Files menu item is displayed, you will see the Files screen.
The files screen shows a list of programs and other files in the /home/lejos/programs directory on the EV3. This directory usually contains runnable jar files containing Java programs, but can also hold other files such as .wav files to play sounds.
You can navigate through the files using the Left and Right keys and select a file using the Enter key.
When you select a file, the File screen will be shown. This gives a set of options, depending on the type of file.
The samples screen:
The Bluetooth screen:
The Wifi screen:
The Sound screen:
The System screen:
The Version screen: