python-can-candle 0.0.1

CAN driver for Geschwister Schneider USB/CAN devices

python-can-candle

CAN driver for Geschwister Schneider USB/CAN devices.

Feature

Support multichannel and can fd.

Installation

pip install python-can-candle

Example

Using with python-can (recommended)

This library implements the plugin interface in python-can, aiming to replace the gs_usb interface within it.

import can
from candle import CandleBus

bus: CandleBus  # This line is added to provide type hints.

with can.Bus(interface='candle', channel=0) as bus:
    # Create listener and notifier.
    print_listener = can.Printer()
    notifier = can.Notifier(bus, [print_listener])

    # Send normal can message without data.
    bus.send(can.Message(arbitration_id=1, is_extended_id=False))
    
    # Send normal can message with extended id
    bus.send(can.Message(arbitration_id=2, is_extended_id=True))
    
    # Send normal can message with data.
    bus.send(can.Message(arbitration_id=3, is_extended_id=False, data=[i for i in range(8)]))

    # Send can fd message.
    if bus.is_fd_supported:
        bus.send(can.Message(arbitration_id=3, is_extended_id=False, is_fd=True, bitrate_switch=True, error_state_indicator=True, data=[i for i in range(64)]))

    # Stop notifier.
    notifier.stop()

candle-api

Using the API directly can be very cumbersome. However, we still provide a simple example for developers to refer to.

from candle.candle_api import CandleDevice, GSHostFrame, GSHostFrameHeader, GSCANFlag

# Scan available devices.
available_devices = list(CandleDevice.scan())

# Select a device.
for i, device in enumerate(available_devices):
    print(f'{i}: {device}')
device = available_devices[int(input('Select a device by index: '))]

# Select a interface.
interface = device[0]

# Select a channel.
channel = interface[int(input(f'Select a channel by index (total {len(interface)}): '))]

# Send a frame.
channel.write(
    GSHostFrame(
        header=GSHostFrameHeader(
            echo_id=0,
            can_id=1,
            can_dlc=8,
            channel=channel.index,
            flags=GSCANFlag(0)
        ),
        data=bytes([i for i in range(8)])
    )
)

# Receive a frame.
frame = channel.read()
print(frame.data)

Reference

https://github.com/torvalds/linux/blob/master/drivers/net/can/usb/gs_usb.c