NINE Communication API

What is it

This project provides definitions and a Python client module to send messages between a client and a server using Protobuf over UDP.

Prerequisites

Follow the instructions here - on how to setup the Dev Board.

How does it work

An example on how to use nine_client.py can be found in test_client.py

1. The client first sends a UDP broadcast message to the server
   • It's assumed the network is 192.168.100.0 and is connected via network interface usb0
   • If needed you can change these defaults
2. The server sends a response back so that the client knowns at which IP address the server resides
3. The client can now send other messages to the server

When updating definitions

If you change definitions/nine.proto, you will need to generate the matching python modules (libnine/nine_pb2.py) - at the same time it will also generate C++ files in libcpp.

You can generate the files by running make lib on a Linux machine.

Testing

• Run make server or python3 test_server.py to launch a test server, this will respond to basic discovery and other messages

Notes when testing

• You're not able to use the python environment or caches from the Linux host on the dev board - so you cannot just mdt push the host files to the dev board
• To copy the files, follow these steps:
  1. host: make clean
  2. host: mdt push . test
  3. host: mdt shell - to login to the board
  4. board: cd test
  5. board: Connect an Ethernet cable to allow for Internet access
  6. board: make .env/.done
  7. board: Disconnect Ethernet cable
  8. board: make client
• Note: if you connect the Ethernet cable before running mdt shell, you might be connected through the wrong IP, so remove it first so the communication goes through the USB cable