CANtact

Software support for CANtact devices. Includes a driver (see driver/), APIs, and a cross-platform command line interface.

Getting a Device

CANtact Pro is currently a pre-launch project on CrowdSupply. You can subscribe on the product page to get updates about the hardware release.

This tool should work fine with other CANtact/gs_usb compatible devices such as CANable.

Installing

The CLI and driver are built using cargo, which can be installed using rustup.

Once cargo is installed, use it to build and install the can binary:

git clone https://github.com/linklayer/cantact
cd cantact
cargo install --path .

Setting udev Rules (Linux only)

On Linux, only root can access the device by default. This results in a DeviceNotFound error when trying to access the device as a normal user. To allow access for all users, create a file at /etc/udev/rules.d/99-cantact.rules which contains:

SUBSYSTEM=="usb", ATTRS{idVendor}=="1d50", ATTRS{idProduct}=="606f", MODE="0666"

Then reload the udev rules:

sudo udevadm control --reload-rules
sudo udevadm trigger

Command Line Interface

The CLI is invoked using the can binary:

can help

can 0.1.0
Eric Evenchick <[email protected]>
Command line utilities for CANtact devices

USAGE:
    can [FLAGS] [SUBCOMMAND]

FLAGS:
    -h, --help       Prints help information
    -v, --verbose    Print verbose debugging information
    -V, --version    Prints version information

SUBCOMMANDS:
    cfg     Set device configurations
    dump    Receive and display CAN frames
    help    Prints this message or the help of the given subcommand(s)
    send    Send a single CAN frame

The can cfg command is used to set the bitrate and other device settings. Once set, other commands will use these options.

For example, to set channels 0 and 1 to 500000 kbps, then dump all frames on all channels:

can cfg --channel 0 --bitrate 500000
can cfg --channel 1 --bitrate 500000
can dump

Use can help [subcommand] for additional documentation.

Rust Support

The driver can be used from Rust by installing the cantact-driver crate. Documentation for the crate can be found on docs.rs.

Python Support

CANtact supports Python 3.5+ on Windows, macOS, and Linux. The Python modules are hosted on PyPI. Installation requires pip 19.0+ (for manylinux2010 wheels).

Python end-users should not use this repository directly. Instead, install Python support using pip:

python3 -m pip -U pip
python3 -m pip install cantact

This will attempt to install a binary distribution for your system. If none exists, it will attempt to build from source. This requires nightly rust, which can be enabled by running rustup default nightly before installing.

See the examples/ folder for Python examples. python-can supports CANtact, and is recommended over using the cantact module directly. To install CANtact, python-can, and run a test:

python3 -m pip install cantact git+https://github.com/ericevenchick/python-can@cantact
can_logger.py -i cantact -c 0 -b 500000

Building Python Support

Building Python support is only required if you want to make modifications to the cantact Python module, or if you are using a platform that does not have packaged support.

Python support is implemented using PyO3, and is gated by the python feature. Thanks to rust-setuptools, the cantact Python module can be built like any other Python module using setuptools. PyO3 requires nightly Rust, which can be configured using rustup override.

cd driver
rustup override set nightly
python setup.py build

Python builds for Windows, macOS, and manylinux are automated using Github Actions. Tagged releases are automatically pushed to PyPI.

C / C++ Support

C / C++ support is provided by the driver. This is currently used to implement BUSMASTER support on Windows.