I wonder if this is the same problem getting the wifi going on Nanopi Neo (not air). See the thread.
Ifconfig would not find wlan0 even though lsusb showed the device was attached.
Seems like dietpi leaves out some of the drivers for wifi.
I did
Try installing full ARMbian firmware package:
Code: Select all
apt-get install armbian-firmware-full
reboot
That brought in about 1K of extra things that got my dongle up and working.