protobuf_client_ros2

ROS 2 client for the MIT AUV Lab's MOOS-ROS bridge

protobuf_client_ros2 is intended to be used with the iMOOSGateway MOOS application.

Please see the moos-ivp-gateway package (https://github.com/mikedef/moos-ivp-gateway) for more information.

protobuf_client_ros2 is a ROS node that serves as a bridge to MOOS-IvP through a predefined Google Protobuf message type. It runs a TCP client using lib_gateway_tcp(adopted from https://github.com/GobySoft/ntsim/tree/master/src/lib/tcp), which allows this application to connect to a MOOS based TCP server, using the same library.

The protobuf_client_node receives key-value pairs sent from the iMOOSGateway application. This data is posted as the rostopic /gateway_msg as a custom ROS message type defined by /msg/Gateway.msg. The /gateway_msg topic can then be subscribed to by an additional data parsing node created by the user. From there the data can be extracted and republished as appropriate ROS message types.

The protobuf_client_ros2 is set to automatically forward any messages posted to the topic specified by the send_to_gateway_topic parameter, which is defaulted to `/send_to_gateway'. The topic data type is of the custom Gateway.msg ROS type and is sent to the gateway via the Gateway.proto message.

• Please see Gateway.msg for more information into the /gateway_msg and /send_to_gateway topics custom data type.

NOTE on the custom Gateway.msg

While it is provided in the protobuf_client_ros2/msg directory this message should be built into its own custom package protobuf_client_interfaces to be used properly by protobuf_client_ros2

• Please be aware of this failure during build time. The package will fail to build due to "protobuf_client_interfaces" missing. Please download the protobuf_client_interfaces ROS 2 package (https://github.com/mikedef/protobuf_client_interfaces) to satisfy this requirement.

• For the following error message error: #error This file was generated by an older version of protoc

  • $ protoc --cpp_out=include/ lib/proto/gateway.proto

Dependencies

• Google protocol buffers
  • sudo apt install protobuf-compiler
• Base64 encode/decode
  • sudo apt install libb64-dev

ROS API

Subs

• send_to_gateway_topic (protobuf_client_interfaces/msg/Gateway)

Pub

• /gateway_msg (protobuf_client_interfaces/msg/Gateway) Received data from MOOS Gateway is automatically published to this topic

ROS Parameters

• gateway_port: default="9501"
  • Port number (tcp_port) of defined in the iMOOSGateway configuration block
• gateway_ip: default="127.0.0.1"
  • IP address of MOOS Gateway
• send_to_gateway_topic: default="/send_to_gateway"
  • Subscribes to this topic to send data to MOOS