Das Script einfach in den Autostart.
#!/bin/bash
# Die ID mit lsusb ermitteln und hier eintragen!
MOUSE_ID="045e:00cb"
while true; do
TOUCHPAD_STATE=`gsettings get org.gnome.desktop.peripherals.touchpad send-events`
MOUSE_PRESENT=`lsusb | grep "$MOUSE_ID"`
if [ "$MOUSE_PRESENT" ] && [ "$TOUCHPAD_STATE" = "'enabled'" ]; then
echo "Disable touchpad."
gsettings set org.gnome.desktop.peripherals.touchpad send-events disabled
elif [ -z "$MOUSE_PRESENT" ] && [ "$TOUCHPAD_STATE" = "'disabled'" ]; then
echo "Enable touchpad."
gsettings set org.gnome.desktop.peripherals.touchpad send-events enabled
fi
sleep 1
done
exit 0