I have a bluetooth trackball that I use with Xorg 1.20.14. Paired up using bluetoothctl with no issues. I don't like the default pointer acceleration so I adjust it via a script when my window manager starts using the following command:

xinput set-prop 'BT4.0+2.4G Mouse' 'libinput Accel Speed' -1.0

After a period of no pointer activity the trackball will go to sleep to retain battery life. When I activate the pointer again it will reconnect to the bluetooth controller and the trackball works. These events can be witnessed via dmesg:

Quote:

[ 200.382014] input: BT4.0+2.4G Mouse as /devices/virtual/misc/uhid/0005:1915:0040.000B/input/input35 [ 200.382194] input: BT4.0+2.4G Mouse Consumer Control as /devices/virtual/misc/uhid/0005:1915:0040.000B/input/input36 [ 200.382335] hid-generic 0005:1915:0040.000B: input,hidraw8: BLUETOOTH HID v0.01 Mouse [BT4.0+2.4G Mouse] on 18:cc:18:9d:31:df [ 215.223740] fuse: init (API version 7.34) [ 215.822315] Bluetooth: RFCOMM TTY layer initialized [ 215.822318] Bluetooth: RFCOMM socket layer initialized [ 215.822321] Bluetooth: RFCOMM ver 1.11 [ 3184.538774] device br0 entered promiscuous mode [ 3201.138412] device br0 left promiscuous mode [57162.024736] input: BT4.0+2.4G Mouse as /devices/virtual/misc/uhid/0005:1915:0040.000C/input/input37 [57162.024901] input: BT4.0+2.4G Mouse Consumer Control as /devices/virtual/misc/uhid/0005:1915:0040.000C/input/input38 [57162.025046] hid-generic 0005:1915:0040.000C: input,hidraw8: BLUETOOTH HID v0.01 Mouse [BT4.0+2.4G Mouse] on 18:cc:18:9d:31:df

My problem is that after reconnecting I need to reissue the xinput command again to set my preferred pointer acceleration.

Is there a way to detect these events and have the script automatically execute after the trackball is reconnected. I assume there's some way to register a listener for events on the bluetooth controller but I've not found any method to do this.

I know can tail and react to syslog messages but I'd prefer to avoid that.

You can create a custom Xorg config file to match against the input device in question and set the acceleration for that device as required...
https://docs.slackware.com/slackbook:xwindow_system
https://fedoraproject.org/wiki/Input..._configuration

1 members found this post helpful.

That looks promising, when I get some time I'll spend more time reviewing those links.

In the meantime I used the DBus monitor (gdbus) to detected connect events from the trackball and set the speed accordingly but I think an Xorg.conf file for trackball would be a better solution.

If I get that working I'll post the solution here once I have it worked out.

I finally got around to looking into this and got it working via an xorg.conf file. I placed the following config block in /etc/X11/xorg.conf.d/99-local.conf.

Section "InputClass"
Identifier "Trackball"
Driver "evdev"
MatchProduct "BT4.0+2.4G|Nordic 2.4G Wireless Receiver"
Option "AccelerationProfile" "1"
Option "ConstantDeceleration" "4.0"
EndSection

This trackball has 2 interfaces, BlueTooth or USB receiver. Xorg.conf doesn't handle hot plug devices so one of the interfaces must be present when X is started. That's not a huge issue for me since I never start X without a pointing device.

Anyway, I hope someone finds this useful.

Glad to read of your progress here and that this approach worked for you.