You must have another way to connect to your robot first before following this tutorial. On the EV3, that means USB or Bluetooth. If you have a Raspberry Pi, you can plug in a monitor and keyboard to the Raspberry Pi. The instructions below are run on your robot itself.

I like to setup wireless networking on my robots. Robots should go untethered! Here is how. It’s easy in an interactive tool call connmanctl. You connect once, and next time you boot, it’s all configured. On my ev3dev machine it went like this:

robot@ev3dev:~$ connmanctl
Error getting VPN connections: The name net.connman.vpn was not provided by any
connmanctl> enable wifi
Enabled wifi
connmanctl> scan wifi
Scan completed for wifi
connmanctl> services
*AO Wired                ethernet_b827ebbde13c_cable
    AH04044914           wifi_e8de27077de3_41483034303434393134_managed_psk
    Frissie              wifi_e8de27077de3_46726973736965_managed_psk
    ruijgt gast          wifi_e8de27077de3_7275696a67742067617374_managed_psk
    schuur               wifi_e8de27077de3_736368757572_managed_psk
connmanctl> agent on
Agent registered
connmanctl> connect wifi_e8de27077de3_41      # You can use the TAB key at this point to autocomplete the name
connmanctl> connect wifi_e8de27077de3_41483034303434393134_managed_psk
Agent RequestInput wifi_e8de27077de3_41483034303434393134_managed_psk
  Passphrase = [ Type=psk, Requirement=mandatory ]
Passphrase? *************
Connected wifi_e8de27077de3_41483034303434393134_managed_psk
connmanctl> quit

You’re all set up now! After reboot connman automatically finds your local Wi-Fi again.