Taken from the archived forum, originally by @tbg
Install the kernel headers and the rtl8188eus driver from the AUR.
The following command will install the linux-headers automatically for all installed kernels:
sudo pacman -S $(pacman -Qsq "^linux" | grep "^linux[0-9]*[-rt]*$" | awk '{print $1"-headers"}' ORS=' ')
Reboot and then run:
pamac build 8188eu-dkms
or
pamac build 8188eu-dkms-git
After the headers and the driver are installed you may need to create a blacklist for the kernel module (if your adapter is not working after rebooting).
Issue the following command to create the blacklist file:
echo 'blacklist 8188eu' | sudo tee /etc/modprobe.d/8188eu-blacklist.conf
Then, do:
sudo depmod -a
sudo mkinitcpio -P
Reboot again.