rtl8821cu

Wifi driver for rtl8811cu/rtl8821cu

Install

sudo ./dkms-install.sh

Remove

sudo ./dkms-remove.sh

Build and install without DKMS

~$ sudo apt install bc linux-headers-$(uname -r)

Use following commands in source directory:

make
sudo make install
sudo modprobe 8821cu

Raspberry Pi

To build this driver on Raspberry Pi you need to set correct platform in Makefile. Change

CONFIG_PLATFORM_I386_PC = y
CONFIG_PLATFORM_ARM_RPI = n
CONFIG_PLATFORM_ARM_RPI3 = n

to

CONFIG_PLATFORM_I386_PC = n
CONFIG_PLATFORM_ARM_RPI = y
CONFIG_PLATFORM_ARM_RPI3 = n

For the Raspberry Pi 3 you need to change it to

CONFIG_PLATFORM_I386_PC = n
CONFIG_PLATFORM_ARM_RPI = n
CONFIG_PLATFORM_ARM_RPI3 = y

Plug your USB-wifi-adapter into your PC

If wifi can be detected, congratulations. If not, maybe you need to switch your device usb mode by the following steps in terminal:

1. find your usb-wifi-adapter device ID, like "0bda:1a2b", by type:

lsusb

2. switch the mode by type: (the device ID must be yours.)

Need install usb_modeswitch (debian: sudo apt install usb_modeswitch)

sudo usb_modeswitch -KW -v 0bda -p 1a2b

It should work.

Modeswitch

Just modify the file /lib/udev/rules.d/40-usb_modeswitch.rules appending before the line LABEL="modeswitch_rules_end" with:

# Realtek 8811CU/8821CU Wifi AC USB
ATTR{idVendor}=="0bda", ATTR{idProduct}=="1a2b", RUN+="usb_modeswitch -K -v 0bda -p 1a2b"