Apple Macbook 1512
Install wifi
sudo apt-get update
sudo apt-get install broadcom-sta-*
sudo modprobe wl
echo "wl" | sudo tee -a /etc/modules
Do not forget the -a in the tee command or you will overwrite the whole file!!
If it doesn’t work right away, reboot and it should be fine.
Mac Mini 2014
This is because MacBook Pro uses a Broadcom Wifi driver which is not open source and so you will have to download and install it yourself.
To do so, open a terminal (Ctrl+Alt+T) and run the following commands:
sudo apt-get update
sudo apt-get --reinstall install bcmwl-kernel-source
sudo modprobe -r b43 ssb wl brcmfmac brcmsmac bcma
sudo modprobe wl
Note: for this a working internet connection is required.
Source: WifiDocs/Driver/bcm43xx from the official Ubuntu documentation.
IF did not help – try
sudo apt-get install bcmwl-kernel-source