[BRLTTY] can't connect Humanware Brailliant BI 40X using bluetooth

[Alexander Epaneshnikov]

Hello Dave.

I am using BRLTTY 6.8 rev BRLTTY-6.8-254-g8352b798
on Arch Linux
brltty starts as unprivileged daemon using upstream provided systemd
units.

connecting my new  BI 40X using usb works fine.
but bluetooth isn't.
my investigation revealed the following

paring and trusting bi 40 x using bluetoothctl or gnome control center
works. but then brltty starts printing folowing in journal:

brltty[1516257]: device open error: /dev/hidraw5: access denied
brltty[1516257]: device open error: /dev/hidraw8: access denied
brltty[1516257]: device open error: /dev/hidraw6: access denied
brltty[1516257]: RFCOMM connect error 111: connection denied

indeed /dev/hidraw6 on my system has
crw------- 1 root root 243, 6 ноя 29 17:16 /dev/hidraw6
by default. if I do
$ sudo chmod -v 660 /dev/hidraw6
then everything starts working. I thought about creating a udev rule but this device doesn't have vendr or product id.
$ udevadm info --attribute-walk --name=/dev/hidraw6

Udevadm info starts with the device specified by the devpath and then
walks up the chain of parent devices. It prints for every device
found, all possible attributes in the udev rules key format.
A rule to match, can be composed by the attributes of the device
and the attributes from one single parent device.

  looking at device '/devices/virtual/misc/uhid/0005:1D6B:0246.00E9/hidraw/hidraw6':
    KERNEL=="hidraw6"
    SUBSYSTEM=="hidraw"
    DRIVER==""
    ATTR{power/control}=="auto"
    ATTR{power/runtime_active_time}=="0"
    ATTR{power/runtime_status}=="unsupported"
    ATTR{power/runtime_suspended_time}=="0"

  looking at parent device '/devices/virtual/misc/uhid/0005:1D6B:0246.00E9':
    KERNELS=="0005:1D6B:0246.00E9"
    SUBSYSTEMS=="hid"
    DRIVERS=="hid-generic"
    ATTRS{country}=="00"
    ATTRS{power/control}=="auto"
    ATTRS{power/runtime_active_time}=="0"
    ATTRS{power/runtime_status}=="unsupported"
    ATTRS{power/runtime_suspended_time}=="0"

  looking at parent device '/devices/virtual/misc/uhid':
    KERNELS=="uhid"
    SUBSYSTEMS=="misc"
    DRIVERS==""
    ATTRS{power/control}=="auto"
    ATTRS{power/runtime_active_time}=="0"
    ATTRS{power/runtime_status}=="unsupported"
    ATTRS{power/runtime_suspended_time}=="0"

do you have any ideas?

--
Sincerely, Alexander