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

[Alexander Epaneshnikov]

Hello. I solved device perms problem with this udev rule:

$ cat /etc/udev/rules.d/90-brltty-hid-bt.rules
# Allow BRLTTY access to Bluetooth HID (uhid) devices from BlueZ
KERNEL=="hidraw*", SUBSYSTEM=="hidraw", SUBSYSTEMS=="hid", KERNELS=="0005:1D6B:0246.*", MODE="0660", GROUP="brltty"

I realize that this rule is too broad, but I don't know of any way to limit it to Braille displays.

If brltty devs are ok with this implementation I can adapt this rule to Autostart/Udev/hid.rules
and send a pr.

On Sat, Nov 29, 2025 at 05:27:20PM +0300, Alexander Epaneshnikov wrote:
> 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

--
Sincerely, Alexander