Repo for the iMOOSGateway application

MOOS-IvP

• Please review the MOOS-IvP (MIT 2.680) class labs for further information about MOOS-IvP

  • https://oceanai.mit.edu/ivpman/pmwiki/pmwiki.php?n=Lab.HomePage2680

• Don't forget to add the path to this repo to the bashrc file!!

  • PATH=$PATH:~/moos-ivp-gateway/bin
  • export PATH

iMOOSGateway

• MOOS application to connect to a client application, if used with the ROS node protobuf_client a ROS based client, to bridge key-value pairs between MOOS-IvP and a non-MOOS system
  • see the mikedef/protobuf_client or the mikedef/protobuf_client_ros2 repository for the ROS based client node
• iMOOSGateway allows for non-MOOS systems to publish MOOS variables into the MOOSDB
• iMOOSGateway allows for the MOOSDB to publish MOOS variables into non-MOOS systems

iMOOSGatway is a generalized application. The user can configure which MOOS variables are to be forwarded to the non-MOOS client application, as shown in the ProcessConfig block below. The user can also specifically block MOOS variables from the client application as needed.

//------------------------------------------                                                            
// iMOOSGateway config block                                                                            
                                                                                                        
ProcessConfig = iMOOSGateway                                                                            
{                                                                                                       
  AppTick   = 4                                                                                         
  CommsTick = 4                                                                                         
                                                                                                        
  tcp_port = 9501                                                                                       
                                                                                                        
  // comma separated moos variables to send to client                                                   
  forward_to_client = DESIRED_HEADING, DESIRED_SPEED, DESIRED_RUDDER, DESIRED_THRUST, DEPLOY, IVPHELM_ST
ATE, IVPHELM_ALLSTOP, IVPHELM_MODESET, DB_TIME                                                         
                                                                                                        
  // comma separated moos variables to block from client                                                
  block_from_client = DEPLOY                                                                            
}  

iMOOSGateway runs a TCP server using lib_gateway_tcp (adopted from https://github.com/GobySoft/netsim/tree/master/src/lib/tcp), which allows the ROS based client (protobuf_client ROS node) to connect to as a TCP client, using the same library.

When iMOOSGateway receives a MOOS variable that is configured to be forwarded in the forward_to_client parameter of the iMOOSGateway configuration block, depending on its type; i.e. string or double, the variable name and the content with be put into a FromGateway protobuf message, and sent over to the client using the TCP connection.

When the client sends a ToGateway type protobuf message over the TCP link, unless if it's a blocked message, the iMOOSGateway application will publish it to the MOOSDB. The content of the incoming message could be a string or a double and will be posted to the MOOSDB as a KEY-VALUE pair.

Data to be sent from the MOOSDB to the client (protobuf_client) will be sent automatically. Data received from the client will be published to the MOOSDB automatically.

See moos-ivp-gateway/src/lib/lib_gateway_protobuf for more information into the gateway.proto message definition. Please note, the gateway.proto msg is defined in both the gateway and the client applications and must be identical.

Dependencies

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

Client Test: protobuf_client

ROS 1

• protobuf_client: https://github.com/mikedef/protobuf_client

ROS 2

Sample test for when the Gateway is in use with the ROS 2 node protobuf_client https://github.com/mikedef/protobuf_client_ros2

• Set the tcp_port to the desired port address in the iMOOSGateway config block
• Launch the MOOS mission in 'moos-ivp-gateway/missions/moos-gateway-alpha'
  • $ ./launch.sh
• Set the gateway_port and gateway_ip in protobuf_client to match the iMOOSGateway settings. gateway_port must match tcp_port
• Launch the gateway client application in ROS 2
  • $ ros2 run protobuf_client protobuf_client_node