How to use CAN#

Attention

sm2s-el requires CAN to be enabled in BIOS setup, see corresponding User Manual for SMARC module in question.

Enabling the CAN interface#

CAN interface must be configure properly and enabled before it can send and receive data.

Check if your CAN interface is available

ip link show CAN0
3: CAN0: <NOARP,ECHO> mtu 16 qdisc noop state DOWN mode DEFAULT group default qlen 10
link/can

Set interface type and bit-rate for the interface

ip link set CAN0 type can bitrate 500000

Now interface can be enabled

ip link set CAN0 up

You can check if interface is up and running

ip link show CAN0
3: CAN0: <NOARP,UP,LOWER_UP,ECHO> mtu 16 qdisc pfifo_fast state UP mode DEFAULT group default qlen 10
link/can

Simple way to test if your CAN is working properly is to employ tools from can-utils package.

Use cansend to send data to a given interface

cansend CAN0 '1234#AABBCCDD'

If everything is working properly message with ID 123 with data AABBCCDD must appear on CAN.

Use candump in the same interface to listen to incoming messages in a given interface

candump CAN0
  CAN0  123   [4]  AA BB CC DD

Q: There is no CAN0/CAN1 interface in output of ip link show

Check if all the necessary kernel modules are loaded

For all SMARC modules

For sm2s-el

For sm2s-imx8plus

e.g. lsmod m_can