Using Asus BT500 bluettoth dongle on Linux system

Depending on Linux kernel version used, the ASUS BT500 may now work as expected out-of-the-box - especially the BLE functionality.

This is caused by a quite new Raltek 8761BU chipset inside the BT500, which is not supported by btrtl Linux kernel driver (it supports 8761B but not the 8761BU).

To solve that problem, a new driver from the ASUS webpage has to be installed on linux.

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Installtion

1. Download driver from the ASUS webpage:

 $ wget https://dlcdnets.asus.com/pub/ASUS/wireless/USB-BT500/20200909_LINUX_BT_DRIVER_KERNEL_5.7_COEX_v0202.zip

2. Change to the driver direcotory - build and install USB driver

$ cd 20200806_LINUX_BT_DRIVER_RTL8761B_COEX_v0202/20200806_LINUX_BT_DRIVER_RTL8761B_COEX_v0202/usb  
$ sudo make install

3. Copy the right FW file and config file to the correct path.

$ sudo cp rtkbt-firmware/lib/firmware/rtl8761bu_fw /lib/firmware/
$ sudo cp rtkbt-firmware/lib/firmware/rtl8761bu_config /lib/firmware/

4. Insert Realtek Bluetooth dongle and check LMP subversion by the following command

$ hciconfig -a

Now RTK chip can be recognized by the system and bluetooth function can be used.

Uninstallation

 $ sudo make uninstall