Today is going well up to now – I purchased a WIFI dongle for around £4 from EBAY, supposedly specifically for Pi (yeah right) market simply “802.11n”. Plugged it in, rebooted the Pi 2, nothing. I scoured the web and discovered you can look to see what’s happening with:
dmesg | more
which shows installed items one page at a time (Spacebar) and sure enough in there was the 802.11 device with a driver missing – looked like a Realtek driver. I went off looking for the name and one of the very first Google responses (sorry I didn’t keep the link) showed a rather long SUDO WGET command to go get the very driver (rtl8188eufw.bin) - did that, reboot – one working WIFI.
So now my little Pi2 has only ONE wire going to it – the power lead from the little solar/usb charger I’m using for battery backup.
I make no suggestion this will help but if you find yourself missing this driver this is what I did in the Pi2 terminal window (then rebooted) – no breaks…
I then went off and tied the IP address and MAC together in my router and that’s me one wire down.