Debian xfce wifi with bcm43142 on HP laptop core i3 intel.

Hello, this is a post about installing wifi on a debian 9.1 with xfce on 
a HP laptop

This debian was installed on a sd card, so that we do not alter the main 
hard drive.

  The wifi chipset is broadcom bcm43142 , (info obtained with "lspci"). 
https://wiki.debian.org/wl is the reference page.

This bcm43142 is not free, and the driver module is not included in the 
default debian kernel.

https://packages.debian.org/broadcom-sta-dkms is the link to the module 
page package. One downloads the driver corresponding to the actual 
debian distribution.

Then install  (in a shell as root) :

dpkg -i nameofthepackage.deb (some other packages like the kernel 
headers have to be present on the system, see the wiki if necessary. )

I compiles well. Then modprobe -r all the b43, ... (as adviced in the 
wiki page) , and "modprobe wl" (always as root).

 From now on it is not necessary to stay as root. Open a new shell (or 
ctrl-D),

check that the module was correctly loaded : lsmod | grep wl

wl                   6443008  0
cfg80211              589824  1 wl

check that the wifi interface exists : enter in a shell "/sbin/iwconfig" 
, one should see a "wlo1" interface. (not necessarily as root).

If one cannot see any wifi  in the network graphical tool, then in the 
special case of xfce wm, there is no automatisation of te process

One has to enter manualy the name of the interface ("wlo1" for me) in 
the line "wireless network"  of the network manager (Wicd) that was empty.

Enjoy !