This is a copy of the RTL8821CU Bluetooth driver tweaked to compile on 3.16 branch of the Linux kernel. Its intention is to be used with Openpeak OpenFrame devices, but no significant changes have been made to the driver.

The RTL8821CU IC provides both 2.5 / 5 GHz WLAN (802.11ac / 802.11abgn) and Bluetooth 4.2 in a single package. This driver is BT only and doesn't provide WLAN compatibility.

However, the code in my rtl8821cu_wlan repo should get wireless up and running with 3.16 kernels as well.

Instructions below apply to OpenFrame Ubuntu Images but should be generic enough to apply to other flavours.

This has been tested against the following adapters:

• EZCast EZC-5200BS (ID 0bda:c820 Realtek Semiconductor Corp.) - Amazon UK

Yes, that's a shill link to Amazon if you'd like to buy one, though they're pretty ubiquitous and easy to identify, even where they've been rebadged.

Ensure you have kernel headers and build-essential installed. These can be added to the OpenFrame automatically with:

of-install-build

Or generically:

sudo apt install linux-headers-`uname -r` build-essential git bluez

git clone https://github.com/andydvsn/rtl8821cu_bt.git
cd rtl8821cu_bt
make	

The make command installs the firmware and module automatically.

Switch to wirless mode:

sudo usb_modeswitch -KW -v 0bda -p c820

Fire up the module with:

sudo insmod ./rtk_btusb.ko

Check its presence with:

hciconfig -a

If you experience any odd behaviour at this point, power down your device entirely, then reboot. The driver should load automatically.