can-waveshare

python-can backend for the Waveshare 2-CH-CAN-TO-ETH bridge that uses a fixed 13‑byte TCP wire format. Works with python -m can.viewer/logger/player and plain can.Bus(...).

Transport: TCP server on the device (e.g., :20001 for CAN1, :20002 for CAN2).
Frames: 13 bytes: [flags/dlc][id:4][data:0..8 padded]

References

• python-can documentation: python-can.readthedocs.io — see Bus API, Command Line Tools, and Configuration.
• Waveshare product page: 2-CH-CAN-TO-ETH and vendor Wiki.

Install

pip install can-waveshare
# or from source (editable):
pip install -e .[dev]

Use with CLI

# Most portable: pass channel as host:port
python -m can.viewer -i waveshare -c 172.31.11.67:20001

# Or forward kwargs directly to the bus:
python -m can.viewer -i waveshare --bus-kwargs host=172.31.11.67 port=20001

Config via ~/.canrc

The stock CLIs read only the [default] section. Put this in ~/.canrc:

[default]
interface = waveshare
channel   = 172.31.11.67:20001

Then:

python -m can.viewer

If you want multiple profiles, either (a) swap rc files or (b) write a tiny launcher in code and use Bus(config_context="waveshare2") to select other sections.

Use in code

import can

# explicit kwargs:
with can.Bus(interface="waveshare", host="172.31.11.67", port=20001) as bus:
    bus.send(can.Message(arbitration_id=0x123, data=b"\x11\x22\x33", is_extended_id=False))
    print(bus.recv(1.0))

# or via channel (parses host:port, tcp://host:port, [ipv6]:port, or aliases can1/can2):
with can.Bus(interface="waveshare", channel="172.31.11.67:20001") as bus:
    print(bus.recv(1.0))

Features & Notes

• CAN 2.0 (0..8 data bytes). CAN‑FD not supported by Waveshare wire format.
• Software filters (can_filters) supported in the backend.
• Best‑effort own‑echo suppression when receive_own_messages=False (default). Set True to see echoes.
• Periodic TX via bus.send_periodic(...) works (python-can broadcast manager calls send() repeatedly).

License

Apache 2.0