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BeagleBone Black CAN bus communication via socketcan

This tutorial is based on a Debian Stretch distribution from 2017-12-12 on the Beaglebone Black. The description is independent of the used CAN cape. I used this CAN cape: BeagleBone Serial Cape from Logic Supply

Setup Debian image

• Download latest BeagleBone Black image from BeagleBone Images, e.g. the Debian Stretch IoT (non-GUI).
• Following the software update guide.
  • For short: Program image to the sd card by using a sd card programming utility.
  • Hold the user/reset button pressed, while powering the board.
• Connect to the BeagleBone Black via ssh.
  • hostname: beaglebone
  • user: debian
  • password: temppwd
• Next important step is to change the password via passwd.
• Update the packages: sudo apt-get update
• Upgrade the distribution: sudo apt-get upgrade

SocketCAN drivers

The BeagleBone should already have the SocketCAN drivers installed, so to use the CAN bus you just need to set the bitrate 125 kBit/s and bring up the CAN0 interface with:

sudo ip link set can0 up type can bitrate 125000
ifconfig

You should see now the can0 interface, similar as shown in the following example.

can0: flags=193<UP,RUNNING,NOARP>  mtu 16
        unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 10  (UNSPEC)
        RX packets 0  bytes 0 (0.0 B)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 0  bytes 0 (0.0 B)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
        device interrupt 166

CAN utilities

if candump is not available, it looks like the CAN utilities are not installed. In this case follow the instructions, otherwise just skip this chapter.

• git clone https://github.com/linux-can/can-utils
• cd can-utils
• apt-get install automake
• ./autogen.sh
• ./configure
• make
• make install

Network interface

• Update the network interface for CAN, to start it automatically during startup: sudo nano /etc/network/interfaces
• Add the following at the end:

allow-hotplug can0
iface can0 can static
    bitrate 125000

Test

To test whether its working or not, lets dump all CAN messages to the console: candump can0 Abort it with strg + c.