Set up your CAN device
======================

List your CAN devices
---------------------

.. note::
   You can also list your CAN interfaces with the script
   :ref:`show-can-devices.sh <reference_show_can_devices>` or 

Your can have physical or virtual CAN interfaces or both. Virtual CAN
interfaces don't require a device driver. They can be created on any Linux
system and just emulate CAN interfaces. This is a great way to test CAN
software without a CAN interface card.

Enter the following command::

  ip link show type vcan; ip link show type can

If virtual CAN interfaces are set up, the output looks like this::

  4: vcan0: <NOARP,UP,LOWER_UP> mtu 72 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
      link/can 
  5: vcan1: <NOARP,UP,LOWER_UP> mtu 72 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
      link/can 
  6: vcan2: <NOARP,UP,LOWER_UP> mtu 72 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
      link/can 
  7: vcan3: <NOARP,UP,LOWER_UP> mtu 72 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
      link/can 

If physical CAN interfaces are set up, the output looks like this::

  3: can0: <NOARP,UP,LOWER_UP> mtu 16 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000
      link/can 
  4: can1: <NOARP,UP,LOWER_UP> mtu 16 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000
      link/can 
  5: can2: <NOARP,UP,LOWER_UP> mtu 16 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000
      link/can 
  6: can3: <NOARP,UP,LOWER_UP> mtu 16 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000
      link/can 

Set up your CAN interfaces
--------------------------

Set up your device driver
+++++++++++++++++++++++++

You need to have a CAN device driver installed for your CAN interface. Some CAN
interface cards however, work with the standard drivers of the Linux Kernel.

The standard kernel also contains drivers for a virtual CAN interface, here a
CAN interface is only emulated.

Initalization of physical CAN interfaces
++++++++++++++++++++++++++++++++++++++++

.. note::
   You can load the driver and initialize your physical CAN interfaces with the
   script :ref:`init-can.sh <reference_init_can>`.

First you may have to load a driver for your CAN bus interface. Here is a short
list of drivers socan was tested with, depending on your CAN interface hardware
your driver name may be different:

- `PCAN-PCI Express FD <https://www.peak-system.com/PCAN-PCI-Express-FD.414.0.html?&L=1>`_: peak_pciefd
- `PCAN-USB <https://www.peak-system.com/PCAN-USB.199.0.html?L=1>`_: peak_usb
- `USB2CAN-Cable <https://www.inno-maker.com/product/usb2can-cable/>`_: not needed, driver is loaded automatically
- `Virtual CAN Bus interface <https://docs.kernel.org/networking/can.html#the-virtual-can-driver-vcan>`_: vcan

If you download and build the
`PEAK-System <https://www.peak-system.com/Home.59.0.html?&L=1>`_ CAN Bus driver
from source, it's name is "pcan".

First see if your CAN driver is loaded (replace 'DRIVER' with the name of the
driver you need)::

  lsmod | grep DRIVER

If the command shows no output, load the driver with::

  sudo modprobe DRIVER

and repeat the 'lsmod' command.

Now list all CAN devices::

  ip link show type can

For each CAN device do::

  sudo ip link set down DEVICE

Set the bit rate (For 1MBit use '1000000' for BITRATE) and set the
transmission queue to 1000::

  sudo ip link set DEVICE type can bitrate BITRATE
  sudo ip link set DEVICE txqueuelen 1000

Now bring the device up::

  sudo ip link set up DEVICE

Initalization of virtual CAN interfaces
+++++++++++++++++++++++++++++++++++++++

.. note::
   You can also initialize your virtual CAN interfaces with the script
   :ref:`init-can.sh <reference_init_can>`.

First see if your CAN driver is loaded::

  lsmod | grep vcan

If the command shows no output, load the driver with::

  sudo modprobe vcan

and repeat the 'lsmod' command.

Now list all CAN devices::

  ip link show type vcan

If there are none shown or you want to add an additional virtual CAN interface
'vcan<N>' where N is a non negative integer (e.g. 'vcan2') enter::

  sudo ip link add dev vcan<N> type vcan

now bring the device up::

  sudo ip link set up vcan<N>

Linking of virtual CAN interfaces
+++++++++++++++++++++++++++++++++

.. note::
   You can also link your virtual CAN interfaces with the script
   :ref:`link-vcan-devices.sh <reference_link_vcan_devices>`.

First show, of a CAN link is already defined::

  cangw -L

If the output looks like this::

  cangw -A -s vcan1 -d vcan0 -e # 0 handled 0 dropped 0 deleted
  cangw -A -s vcan0 -d vcan1 -e # 0 handled 0 dropped 0 deleted

the link (here between vcan0 and vcan1) is already defined.

If the link is not defined, you can add a link between two interfaces DEVICE1
and DEVICE2 (e.g. 'vcan0' and 'vcan1') like this::

  sudo cangw -A -s DEVICE1 -d DEVICE2 -e
  sudo cangw -A -s DEVICE2 -d DEVICE1 -e

You may remove the same link later on with::

  sudo cangw -D -s DEVICE1 -d DEVICE2 -e
  sudo cangw -D -s DEVICE2 -d DEVICE1 -e

Scripts and programs provided by socan
--------------------------------------

These are described here: :doc:`programs`.