.. _can-bus:

CAN Bus
^^^^^^^^^^^^^^

This gateway features up to two CAN 2.0B ports:

* ``canE``: permanent; always enabled and accessible
* ``canC``: optional; always enabled, but accessible only when the CAN I/O module is installed

Interface configuration
""""""""""""""""""""""""

Configure the CAN interface bitrate to 1 Mbit/sec::

   $ sudo ip link set canE type can bitrate 1000000

Enable the CAN interface::

   $ sudo ip link set canE up

Send/receive packets
""""""""""""""""""""""

Send standard CAN frame (on the first device):

.. code:: console

   $ sudo cansend canE 111#1122334455667788


Send extended CAN frame (on the first device):

.. code:: console

   $ sudo cansend canE 11111111#1122334455667788


Example of CAN frame generator (extended mode) with random payload and 50 msec interval between successive frames:

.. code:: console

   $ sudo cangen -g 50 -e -D r -v canE
   ...
      canE  1E5137F4#0F.4D.8B.7A.25.4D.DB.21
      canE  1B6C965C#8C.DE.96.58.69.5F.D5.26
      canE  1BD23086#8D.DB.C4.3E.81.57.BA.34
      canE  127B2322#F4.16.31.2E.34.04.62
      canE  1A6366DB#A8.73.C0.37.D8
      canE  03620EE4#
      canE  023AC34D#C6.08.BD.2A.04.B3.BF.43
      canE  1C19AD2E#09.C1.B3.26.23.E5.6A.5A
      canE  02BCA994#48.32.46.7C.F0.3F.29.1E
      canE  08104C67#59.9F.FE.44
      canE  1C280582#6F.D4.9C.38.A5.28.A3
      canE  0BC219EE#D9.2C.05
      canE  04AA80B8#A1.93
      canE  1A3E2392#AD.98
      canE  0025950E#E3.99.38
   ...


Dump all received data frames as well as error frames:

.. code:: console

   $ sudo candump any,0:0,#FFFFFFFF
   ...
      canE  0CC89C1A   [1]  51
      canE  0A097EFB   [0] 
      canE  02B59BD5   [5]  68 6F 47 64 D9
      canE  03743A1E   [7]  FA BF E4 38 3E BF C8
      canE  13C9B644   [8]  30 FB 60 6F E1 FC 55 65
      canE  018A8975   [0] 
      canE  0C9C8179   [0] 
      canE  011F5D90   [6]  65 DB DD 5A AA F9
      canE  07B7FD18   [6]  CC 96 26 1D 13 7C
      canE  1FBD7177   [8]  69 BF 8D 1E 4C 0D 73 02
      canE  107A7E2D   [2]  25 D3
      canE  12B9E279   [8]  89 77 B7 54 BD 98 83 06
      canE  112A44EA   [8]  9E 95 D9 6B 60 CE B4 52
      canE  0ADF9869   [3]  C8 A0 27
      canE  1580C274   [5]  B2 7A F7 43 04
      canE  06DDDBCC   [7]  AF 19 88 04 E4 D8 95
      canE  127FA5CE   [8]  F7 54 57 20 45 17 3D 12
      canE  09A37893   [0] 
      canE  01BA4332   [6]  0B AF 0C 2E AB 25
      canE  180A8AD5   [5]  68 BE F7 5A C0
      canE  06DC994E   [7]  20 9E E9 7B B8 31 BC
   ...