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Bothy

Robots and ROS 2

examples/pi-agent is a complete agent for Raspberry Pi class boards:

  • it takes missions that the Flutter demo app writes;
  • it marks them accepted and then done;
  • it writes readings of the board (CPU temperature, load, memory) as telemetry.

It works offline and catches up later. It was tested on a 4-core Cortex-A53 board through 48 hours of offline telemetry (2,880 records), with peak memory under 32 MiB while syncing.

Terminal window
pip install bothy
python3 agent.py login --client client_tv.json            # once: code to enter on your phone
BOTHY_PASSWORD='…' python3 agent.py run --folder robot    # first run joins the database
python3 agent.py run --folder robot --p2p                 # later runs use the kept key
  • --p2p: connects directly to the phone while both are online, so a mission arrives in about a second.
  • The data key is kept in ~/.local/share/bothy-agent/key (mode 0600), so later runs need no password and no Argon2 memory.
  • As a service: bothy-agent.service is a user-level systemd unit.

ROS 2

Section titled “ROS 2”

With a sourced ROS 2 environment, --ros2 bridges the database to two topics:

  • each accepted mission is published as JSON on /bothy/missions;
  • JSON messages on /bothy/telemetry are stored as telemetry.
Terminal window
source /opt/ros/humble/setup.bash
python3 agent.py run --folder robot --ros2
ros2 topic echo /bothy/missions
ros2 topic pub --once /bothy/telemetry std_msgs/String "{data: '{\"battery\": 0.8}'}"

For C++ nodes, see C and C++.

Why a folder database

Section titled “Why a folder database”

Boards sign in with the device code flow, which Google only allows with the drive.file scope. So the robot and the phone share a visible Bothy/robot folder. In the demo app, set BOTHY_DRIVE_FOLDER=robot.