bwi Wi-Fi device timeout

Hello NetBSD macppc community,
my name is Matteo Bini and I'm new to NetBSD.

A week ago I installed NetBSD on my 2005 Mac mini. NetBSD is such a cool
system that lets me use a nearly 20 years old computer with an up to
date operating system, crafted very carefully. It reminds me of 90s IT
style. So first of all, thank you for making NetBSD!

I would like to use the Mac mini onboard Wi-Fi device (bwi0), therefore
I've downloaded the needed firmware from
<http://leaf.dragonflybsd.org/~sephe/bwi/v3.tbz> and I've installed it
in /libdata/firmware/bwi. However I get a device timeout error message
from the driver (bwi), both at startup and when I do a network scan,
with `wpa_cli scan` and `wpa_cli scan_results`. The results command
returns an empty line, like no networks were found. Obviously where I'm
testing there are many Wi-Fi networks that the Mac mini should be able
to connect to.

Do you have any experiences with bwi Wi-Fi devices? Does bwi work with
Mac minis? Should I settle for an external USB Wi-Fi device? If yes, do
you have any recommendations? Coming from GNU/Linux, I know Wi-Fi can be
a pain.

Thank you for the help.

-- 
Matteo Bini