Raspberry Wifi Setup HeadLess

After installing Raspbian on your new Micro SD Card.

Connect the SDCard to your laptop using a adpater MicroSD to SD Adapter or using an MicroSD to USB adapter.

Under the terminal on your MacOSX, go to the boot mount point

cd /Volume/boot
vi wpa_supplicant.conf

After add in the new file

country=FR
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1
network={
        scan_ssid=1
        ssid="YourSSID"
        psk="yourkey"
        key_mgmt=WPA-PSK
}

If you need ssh (sure you need) in the same directory

/Volume/boot/# touch ssh

Sources: https://www.raspberrypi.org/documentation/configuration/wireless/headless.md