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CAN Bus
Contents
- 1 Overview
- 2 CAN Support in Linux
- 2.1 SocketCAN Supported
Protocols - 2.2 SocketCAN Supported
Controllers - 2.3 SocketCAN Support in Programming
Languages/Environments - 2.4 can4linux Supported
Controllers - 2.5 can4linux Support in Programming
Languages/Environments - 2.6 CAN Controllers Emulation
(WIP/experimental) - 2.7 SocketCAN Bechmarking
- 2.8 SocketCAN Tutorials
- 2.1 SocketCAN Supported
Overview
The CAN bus is an ISO standard bus originally developed for vehicles. It
manages the Chassis Electrical System Control and is responsible for
critical activities like engine electrical, and skid control. This
system is also used to provide vehicle diagnostic information for
maintenance. A multi-star configuration seems typical of this bus with a
primary bus line that branches into sub bus lines at its extremities
then attaches to multiple device nodes. Differential voltage is applied
over twisted pair at 1.5 to 2.5V and 2.5 to 3.5V for noise resistant
signaling. Bit rates up to 1 Mbit/s are possible at network lengths
below 40 m. Decreasing the bit rate allows longer network distances
(e.g., 500 m at 125 kbit/s). (Jeremiah J. Flerchinger
Source) Controllers supporting
CAN FD, an enhanced CAN version with frames up to 64 byte and bit rates
up to 4 Mbit/s, will be available in the second half of 2014. A
can4linux version supportig CAN FD on a IFI
CAN is ready to be used.
Although developed as car communication network CAN is used in many
other areas, industrial, medical, maritime laboratory and more. Most
often with a CAN based higher layer protocol like
CANopen on top of it.
Additional information can be found at:
http://en.wikipedia.org/wiki/CAN_bus
CiA CAN in Automation CAN user association
CAN FD Specification Version
1.0
CAN Support in Linux
CAN is supported by Linux device drivers. Mainly two types exist.
Character device based drivers and network socket based drivers. The
Linux kernel supports CAN with the SocketCAN framework.
- SocketCAN
Documentation - mailing list for Linux Kernel CAN
development - linux-can git
repository - linux-can-next git
repository - Berlios Project Page
(obsolete)
One of the character based drivers is can4linux.
SocketCAN Supported Protocols
- RAW: send & receive raw CAN frames
- BCM: Broadcast manager, offload repetitive work to the Linux kernel
- ISOTP …
- SAE J1939
SocketCAN Supported Controllers
- Microchip MCP251x
- Atmel AT91 SoCs
- ESD 331 CAN Cards
- NXP (Philips) SJA1000
- Freescale MPC52xx SoCs
- Bosch CC770
- Intel AN82527
- TIs SoCs
- Serial/network devices utilizing ASCII protocol (slcan driver)
| Vendor | Device Name | Driver Module Name | Controller | Kconfig Option | Linux Mainline | Remarks |
|---|---|---|---|---|---|---|
| VScom | NET-CAN | slcan | (unknown) | CONFIG_CAN_SLCAN | 2.6.38 | needs slcand and socat |
| VScom | PCI-2CAN | slcan | (unknown) | CONFIG_CAN_SLCAN | 2.6.38 | needs slcand |
| VScom | SER-CAN | slcan | (unknown) | CONFIG_CAN_SLCAN | 2.6.38 | needs slcand |
| VScom | USB-CAN | slcan | (unknown) | CONFIG_CAN_SLCAN | 2.6.38 | needs slcand |
| LAWICEL | CAN232 | slcan | (unknown) | CONFIG_CAN_SLCAN | 2.6.38 | needs slcand |
| LAWICEL | CANUSB | slcan | (unknown) | CONFIG_CAN_SLCAN | 2.6.38 | needs slcand |
| PEAK | PCAN-PCI | peak_pci | sja1000 | CONFIG_CAN_PEAK_PCI | 3.2 | supports all PCAN-[mini]PCI[e][104] variants |
| PEAK | PCAN-USB | peak_usb | (unknown) | CONFIG_CAN_PEAK_USB | 3.4 | supports PCAN-USB[pro][hub] (no LIN support) |
| Kvaser | PCIcanx | kvaser_pci | sja1000 | CONFIG_CAN_KVASER_PCI | 2.6.31 | supports all PCI-[mini]PCI[e][104] variants |
| Kvaser | Leaf | kvaser_usb | (unknown) | CONFIG_CAN_KVASER_USB | 3.8 | supports USB Leaf / Memorator / Blackbird / R (see detailed USB device IDs in kvaser_usb.c) |
| Kvaser | USBCan-II | kvaser_usb | (unknown) | CONFIG_CAN_KVASER_USB | commits pulled-in for the 3.20 release | supports:
|
| EMS Wünsche | CPC-Card | ems_pcmcia | sja1000 | CONFIG_CAN_EMS_PCMCIA | 3.2 | discontinued |
| EMS Wünsche | CPC-USB/ARM7 | ems_usb | (unknown) | CONFIG_CAN_EMS_USB | 3.2 | |
| EMS Wünsche | CPC-PCI/PCIe | ems_pci | sja1000 | CONFIG_CAN_EMS_PCI | 3.2 | up to four channel |
| EMS Wünsche | CPC-PC104P | ems_pci | sja1000 | CONFIG_CAN_EMS_PCI | 3.2 | up to four channel on a PC104+ board |
| 8devices | USB2CAN | usb_8dev | (STR750FV2) | CONFIG_CAN_8DEV_USB | 3.9 | STR750FV2 Firmware |
| Softing | CANcard2 | softing_cs | sja1000 or NEC-005(?) | CONFIG_CAN_SOFTING_CS | 2.6.38 | Supports {CAN,EDIC}card{,SJA,2} PCMCIA cards Needs firmware softing-fw-4.6-binaries.tar.gz |
SocketCAN Support in Programming Languages/Environments
can4linux Supported Controllers
- Allwinner A20 with integrated CAN (on
the popular BananaPi single-board
computer.) - Analog Devices BlackFin BF537
- Atmel AT91 SoCs
- Freescale FlexCAN (ColdFire 5282,
i.MX25, i.MX28, i.MX35) - Intel 82527 (the replacement Bosch CC770 should work)
- Microchip Stand Alone CAN MCP2515
- NXP Stand Alone CAN
SJA1000 (on
different ISA or PCI/PCIe boards) - Xilinx
Zynq with XCAN - ‘virtual’ CAN mode without CAN hardware
- ‘virtual’ CAN mode supporting CAN
FD - IFI CAN FPGA IP, in
classic CAN mode and CAN FD mode
can4linux Support in Programming Languages/Environments
- C - many examples and useful applications are provided with the
package, check can4linux-examples/ - Tcl/Tk
also in can4linux-examples/ - Python
also in can4linux-examples/
CAN Controllers Emulation (WIP/experimental)
- SJA1000 CAN controller based PCI board emulation for QEMU
- Cards models provided:
- Simple memory mapped SJA1000 in the first PCI BAR with
ad-hoc PCI ID - Kvaser PCIcan-S single I/O mapped SJA1000 model compatible
with kvaser_pci Linux driver on guest side
- Simple memory mapped SJA1000 in the first PCI BAR with
- The emulated CAN buses can be connected to virtual or physical
SocketCAN interface if Linux is used as host system - Project repository:
https://github.com/CTU-IIG/qemu - Work started by 2013 GSoC project when RTEMS project donated its
slot to work on QEMU CAN support - see RTEMS related
page
for more info and use instructions
- Cards models provided:
