Tp-Link UB500 Bluetooth dongle on Ubuntu 20.04

gistfile1.md

The dongle is recognized but the bluetooth UI does not respond

sudo dmesg | grep -i bluetooth

[  371.792424] Bluetooth: hci0: RTL: loading rtl_bt/rtl8761bu_fw.bin
[  371.792455] bluetooth hci0: Direct firmware load for rtl_bt/rtl8761bu_fw.bin failed with error -2
[  371.792459] Bluetooth: hci0: RTL: firmware file rtl_bt/rtl8761bu_fw.bin not found

Need to create a couple of symlinks and remove/plug the dongle again:

sudo ln -s /usr/lib/firmware/rtl_bt/rtl8761b_fw.bin /usr/lib/firmware/rtl_bt/rtl8761bu_fw.bin
sudo ln -s /usr/lib/firmware/rtl_bt/rtl8761b_config.bin /usr/lib/firmware/rtl_bt/rtl8761bu_config.bin

Reference: https://bugs.launchpad.net/ubuntu/+source/linux-firmware/+bug/1968604

And if you want to use the microphone in your fancy bluetooth headphones, you will need to replace PulseAudio with PipeWire so you can use the Handsfree one (HFP) and not only the Headset profile (HSP):

https://askubuntu.com/questions/1085960/use-bluetooth-headset-with-microphone-hfp-in-ubuntu-18-04

Note that while in the HSP profile music will sound awful, so you will have to switch to the A2DP profile for that 🤷‍♂️