How to install unsupported Bluetooth 5.0 Dongle on Linux

I bought a cheap Bluetooth dongle on Amazon without reading the characteristics carefully… and now I must tell you a little story.

The dongle that I bought…

One of my home desktop computers lacks Bluetooth 5.0 support and I needed one because of the dual-mode connection and better speeds.

So I was blind to ordering the cheapest dongle I could find… without researching a little more about my future device.

After it arrives, I couldn't make it to work on my Linux machine.

I tested on another Windows 10 Pro machine and it works.

So I head back to the manufacturer website and then I saw this :

No Linux Compatibility :(

So after doing some research I tried to fix the problem by myself, reading the official documentation of the device I see that the dongle has an RTL8761B chipset, so knowing this makes the process easier to find and fix.

These will be the steps to install the dongle successfully in Linux, in this case, Debian-based Linux.

To check the problem I use the “dmesg” command to have more insight information about the error.

sudo dmesg | grep Bluetooth

You will see something like this… that means that we need to install the firmware for this chipset because the file is not there.

So let's follow these small steps to have it working :

1. Navigate to this URL to download the chipset driver compressed file, I found it on the official Arch package: https://aur.archlinux.org/packages/rtl8761b-fw/ (if this link it’s not working, new links added below for the individual files)
   - https://raw.githubusercontent.com/Realtek-OpenSource/android_hardware_realtek/rtk1395/bt/rtkbt/Firmware/BT/rtl8761b_config
   - https://raw.githubusercontent.com/Realtek-OpenSource/android_hardware_realtek/rtk1395/bt/rtkbt/Firmware/BT/rtl8761b_fw
2. Uncompressed the downloaded file
3. Navigate where the driver file is, in my case was in 20201202_LINUX_BT_DRIVER/rtkbt-firmware/lib/firmware/rtlbt
4. Now we must copy the firmware files to the /usr/lib/firmware/rtl_bt and rename it .bin extension, for this we need sudo for permissions. There are two files we need: rtl8761b_config and rtl8761b_fw

sudo cp rtl8761b_config /usr/lib/firmware/rtl_bt/rtl8761b_config.bin
sudo cp rtl8761b_fw /usr/lib/firmware/rtl_bt/rtl8761b_fw.bin

5. After copying the files, we need to unplug the USB dongle again or reboot your pc and check the “dmesg” command again, if everything goes well the missing file error “not found” will not be present anymore.

6. That’s it … Enjoy your Bluetooth 5.0 connection :)

Note: if your Linux OS upgrades the firmware in the future, you will need to repeat this steps again to have the device drivers installed after upgrading, so I recommend to read well if an upgrade to the system will also upgrades the firmware, if for any reason your Bluetooth dongle stops working… you know what to do again.

I hope this mini-guide will help others like me :)