pi@raspberrypi:~ $ lsusb
Bus 001 Device 006: ID 0bda:8176 Realtek Semiconductor Corp. RTL8188CUS 802.11n WLAN Adapter
Bus 001 Device 005: ID 046d:c312 Logitech, Inc. DeLuxe 250 Keyboard
Bus 001 Device 004: ID 046d:c050 Logitech, Inc. RX 250 Optical Mouse
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp. SMSC9512/9514 Fast Ethernet Adapter
Bus 001 Device 002: ID 0424:9514 Standard Microsystems Corp.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

pi@raspberrypi:~ $ cat /etc/network/interfaces
# interfaces(5) file used by ifup(8) and ifdown(8)

# Please note that this file is written to be used with dhcpcd
# For static IP, consult /etc/dhcpcd.conf and 'man dhcpcd.conf'

# Include files from /etc/network/interfaces.d:
source-directory /etc/network/interfaces.d

auto lo
iface lo inet loopback

iface eth0 inet manual

auto wlan0
allow-hotplug wlan0
iface wlan0 inet dhcp
 #   address 192.168.1.100
 #   netmask 255.255.255.0
 #   gateway 192.168.1.1
    wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

allow-hotplug wlan1
iface wlan1 inet manual
    wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf

pi@raspberrypi:~ $ sudo cat /etc/wpa_supplicant/wpa_supplicant.conf
country=GB
ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
update_config=1

network={
    ssid="ASUS"
    psk="MYPASSWORD"
    id_str="edup"
}

pi@raspberrypi:~ $ sudo iwlist wlan0 scan
wlan0     Scan completed :
          Cell 01 - Address: 00:26:18:C3:BA:22
                    ESSID:"ASUS"
                    Protocol:IEEE 802.11bg
                    Mode:Master
                    Frequency:2.462 GHz (Channel 11)
                    Encryption key:on
                    Bit Rates:54 Mb/s
                    Quality=96/100  Signal level=66/100

pi@raspberrypi:~ $ uname -a
Linux raspberrypi 4.4.9-v7+ #884 SMP Fri May 6 17:28:59 BST 2016 armv7l GNU/Linux

pi@raspberrypi:~ $ find /lib/modules | grep 8192cu
/lib/modules/4.4.9-v7+/kernel/drivers/net/wireless/realtek/rtl8192cu
/lib/modules/4.4.9-v7+/kernel/drivers/net/wireless/realtek/rtl8192cu/8192cu.ko
/lib/modules/4.4.9+/kernel/drivers/net/wireless/realtek/rtl8192cu
/lib/modules/4.4.9+/kernel/drivers/net/wireless/realtek/rtl8192cu/8192cu.ko

pi@raspberrypi:~ $ lsmod
Module                  Size  Used by
bnep                   10340  2
bluetooth             326105  5 bnep
cfg80211              427855  0
rfkill                 16037  4 cfg80211,bluetooth
8192cu                519156  0
evdev                  11396  4
snd_bcm2835            20511  1
snd_pcm                75698  1 snd_bcm2835
snd_timer              19160  1 snd_pcm
snd                    51844  5 snd_bcm2835,snd_timer,snd_pcm
bcm2835_gpiomem         3040  0
bcm2835_wdt             3225  0
uio_pdrv_genirq         3164  0
uio                     8000  1 uio_pdrv_genirq
i2c_dev                 5859  0
fuse                   83461  3
ipv6                  347530  48