Realtek 8811CU driver for Raspberry Pi OS

Driver for 802.11ac USB adapter with RTL8811CU chipset, only STA/Monitor mode is supported, no AP mode.

A few known wireless cards that use this driver include:

• Fastoe AC650 USB Wi-Fi Adapter
• TOTOLINK A650UA v3
• D-Link - DWA-171C
• BrosTrend AC5L
• EDUP EP-AC1651
• EDUP EP-AC1635
• Cudy WU700

Tested with Raspberry Pi OS (32-bit):

• Kernel 5.10.17
• Kernel 5.4.83
• Kernel 5.4.79
• Kernel 4.19.118
• Kernel 4.19.50

Tested Raspberry Pi Devices:

• Raspberry Pi 400
• Raspberry Pi 4 Model B 2G
• Raspberry Pi 4 Model B 4G
• Raspberry Pi 4 Model B 8G
• Raspberry Pi Zero W
• Raspberry Pi Zero v1.3
• Raspberry Pi 3 B+
• Raspberry Pi 2 B

Installation Information

To build, you have to retrieve source and run make, do following:

• For Raspberry Pi OS 5.10 kernel, clone the v5.8.1 branch:

  sudo apt install -y bc git dkms build-essential raspberrypi-kernel-headers
  git clone -b v5.8.1 https://github.com/fastoe/RTL8811CU_for_Raspbian
  cd RTL8811CU_for_Raspbian
  make
  sudo make install
  sudo modprobe 8821cu
  sudo reboot
  

• For Raspberry Pi OS 5.4 or earlier kernel:

  sudo apt install -y bc git dkms build-essential raspberrypi-kernel-headers
  git clone https://github.com/fastoe/RTL8811CU_for_Raspbian
  cd RTL8811CU_for_Raspbian
  make
  sudo make install
  sudo modprobe 8821cu
  sudo reboot
  

If fails to compile like /lib/modules/5.x.x-v7+/build: No such file or directory. Stop:

pi@raspberrypi:~/RTL8812BU_for_Raspbian $ make
make ARCH=arm CROSS_COMPILE= -C /lib/modules/5.4.51-v7+/build M=/home/pi/RTL8812BU_for_Raspbian  modules
make[1]: *** /lib/modules/5.x.x-v7+/build: No such file or directory.  Stop.
make: *** [Makefile:2284: modules] Error 2

please run the rpi-source command to install the kernel headers for kernel:

sudo apt install -y bc git flex bison libssl-dev libncurses5-dev
sudo wget https://raw.githubusercontent.com/RPi-Distro/rpi-source/master/rpi-source -O /usr/local/bin/rpi-source && sudo chmod +x /usr/local/bin/rpi-source && /usr/local/bin/rpi-source -q --tag-update
rpi-source

then, re-make again.

If fails to compile like this:

make ARCH=arm CROSS_COMPILE= -C /lib/modules/5.4.51-v7+/build M=/home/pi/rtl8821CU  modules
make[1]: Entering directory '/home/pi/linux-f2f7e4b23d8788e96f81a7522b2f703e51c53e70'
  CC [M]  /home/pi/rtl8821CU/core/rtw_cmd.o
gcc: error: -mfloat-abi=soft and -mfloat-abi=hard may not be used together
make[2]: *** [scripts/Makefile.build:266: /home/pi/rtl8821CU/core/rtw_cmd.o] Error 1
make[1]: *** [Makefile:1709: /home/pi/rtl8821CU] Error 2
make[1]: Leaving directory '/home/pi/linux-f2f7e4b23d8788e96f81a7522b2f703e51c53e70'
make: *** [Makefile:2214: modules] Error 2

please run the following command:

• for AArch32 (32-bit)

sudo cp /lib/modules/$(uname -r)/build/arch/arm/Makefile /lib/modules/$(uname -r)/build/arch/arm/Makefile.$(date +%Y%m%d%H%M)
sudo sed -i 's/-msoft-float//' /lib/modules/$(uname -r)/build/arch/arm/Makefile
sudo ln -s /lib/modules/$(uname -r)/build/arch/arm /lib/modules/$(uname -r)/build/arch/armv7l

• for AArch64 (64-bit)

sudo cp /lib/modules/$(uname -r)/build/arch/arm64/Makefile /lib/modules/$(uname -r)/build/arch/arm64/Makefile.$(date +%Y%m%d%H%M)
sudo sed -i 's/-mgeneral-regs-only//' /lib/modules/$(uname -r)/build/arch/arm64/Makefile

then, re-make again.

Enjoy!