I had an older version of DietPi (158), on which wifi was working fine. However, I cannot get v6.4 to use wifi at all. I tried editing the dietpi.txt file before first boot to enter my wifi details - no luck. I also try to make changes using dietpi-config after the first boot and it will not permit me to scan available wifi - the screen simply flashes with no error. dietpi-config confirms that wifi is enabled.
I can confirm my router has WPA2 configured.
Connecting an ethernet cable results in a success.
Just to make sure there was nothing wrong with the hardware, I flashed an older version of diet pi as a fresh install and the wifi works just fine during first boot.
Similar issue here.
Previous version works fine.
Just format a new SD to test the new version.
Error message was “device not found” upon boot or dietpi-config
Confirmed hardware functional by swapping SD.