bluetooth_monitor

Description

This node monitors a Bluetooth connection to a wireless device by using L2ping.
L2ping generates PING echo command on Bluetooth L2CAP layer, and it is able to receive and check echo response from a wireless device.

Block diagram

L2ping is only allowed for root by default, so this package provides the following approach to minimize security risks as much as possible:

• Provide a small program named l2ping_service which performs L2ping and provides wireless device information to bluetooth_monitor by using socket programming.
• bluetooth_monitor is able to know wireless device information and L2ping status as an unprivileged user since those information are sent by socket communication.

Output

bluetooth_monitor: bluetooth_connection

[summary]

[values]

• The following key will be added when bluetooth_monitor reports Function error.
  ex.) The connect system call failed.

Parameters

{{ json_to_markdown(“system/bluetooth_monitor/schema/bluetooth_monitor.schema.json”) }}

• rtt_warn

  • 0.00(zero): Disable checking RTT
  • otherwise: Check RTT with specified seconds

• addresses

  • *: All connected devices
  • AA:BB:CC:DD:EE:FF: You can specify a device to monitor by setting a Bluetooth address

Instructions before starting

• You can skip this instructions if you run l2ping_service as root user.

1. Assign capability to l2ping_service since L2ping requires cap_net_raw+eip capability.

   sudo setcap 'cap_net_raw+eip' ./build/bluetooth_monitor/l2ping_service
   

1. Run l2ping_service and bluetooth_monitor.

   ./build/bluetooth_monitor/l2ping_service
   ros2 launch bluetooth_monitor bluetooth_monitor.launch.xml
   

Known limitations and issues

None.