In raspbian is working, compiling and using the command 'sudo usb_modeswitch -KW -v 0bda -p 1a2b'
In this repo GitHub - uzh-rpg/rpg_dwa171_wifidongle: Realtek 802.11ac USB WLAN driver there is a script to not use previous command.
Display MoreI was going to ask about this device also! I just bought this USB Wi-Fi device which does 5GHZ hoping to get some speed improvement for a RPi3 at locations not easy to use a RJ45 cable. A Fire Stick running Kodi at the same location as the RPi3 gives very good download speed for playback as it uses 5GHZ but the RPi3 only uses 2.4 GHZ which gives too much buffering. This device has external aerial which I hoped would give better performance than the RPi3 internal 5GHZ aerial!
As has been said the supplied Linux drivers dont work with recent versions of Linux but I found the modified drivers on Github mentioned in the first post. On my Ubuntu 18.04 PC the driver installed without error and finds the USB Wi-Fi device which runs at 5GHZ. The default platform to make a driver for is a PC but there are numerous other options including to make for a RPi and RPi3 so I created a Raspbian SD card and tried to install the driver as mentioned above by Iridium. Making for RPi3 the first error was that /lib/modules/4.14.79-v7+/build could not be found so created the "build" directory which was not a good start!!
Typing "make " again:-
pi@raspberrypi:~/Downloads/rtl8821CU-master $ make
/bin/sh: 1: bc: not found
make ARCH=arm64 CROSS_COMPILE= -C /lib/modules/4.14.79-v7+/build M=/home/pi/Downloads/rtl8821CU-master modules
make[1]: Entering directory '/lib/modules/4.14.79-v7+/build'
make[1]: *** No rule to make target 'modules'. Stop.
make[1]: Leaving directory '/lib/modules/4.14.79-v7+/build'
Makefile:1923: recipe for target 'modules' failed
make: *** [modules] Error 2
This error exceeds my level of incompetence on the subject so gave up!!
Chris
Install bc, and use 'make ARCH=arm'