CAN-FD USB converter

This is an STM32-based CAN-FD USB Converter. CAN-FD is an extension of CAN with options for higher bit rates and larger payloads. It is compatible with tools such as SocketCAN, can-utils(cansend/candump) and pythonCAN.

Fork

This is a fork of https://github.com/ucandevices/CFDC_embedded. Here are some differences:

• It is ported from STM32G431CBUx to STM32G491MET.
• Our board uses a crystal instead of the internal oscillator.
• The pinout is different.
• There are two CAN drivers but only 1 is used.
• The CAN-drivers have a standby pin, which is not used.
• it is made with a newer version of STM32CubeMX: 6.4.0

Build

Build with STM32CubeIde V1.8.0 and flash with an ST-link.

Run

Install tools

Install can-utils

sudo apt-get install can-utils

Install ucan_utils

git clone https://github.com/ucandevices/ucan_utils --recurse-submodules
cd ucan_utils
make

sudo modprobe vcan
sudo ip link add dev vcan0 type vcan
sudo ip link set up vcan0

Start uccbsocketcan with configuration

Run this and keep this running

sudo ./uccbsocketcan -cvcan0 -d250 -i250 -fc -mn

Monitor messages

candump vcan0

Send messages

Not extended:

cansend vcan0 123#112233 

Force extended:

cansend vcan0 00000123#112233

Extended:

cansend vcan0 18FEEEFE#112233

Python with python-can

open:

import can
with can.interface.Bus(interface="socketcan", channel="vcan0", fd=True) as bus:

Send:

msg = can.Message(
    arbitration_id=0x123, 
    data=[0x11,0x22,0x33,0x44,0x55,0x66,0x77,0x88], 
    is_extended_id=True
)

bus.send(msg)

Read:

msg = bus.recv(1)
if msg is not None:
    print(msg)

C

Plenty of examples of socketcan exist such as can-utils. Make sure to activate CAN-FD or you won't be able to receive data. Activate CAN-FD

static const int canfd_on = 1;
setsockopt(s, SOL_CAN_RAW, CAN_RAW_FD_FRAMES, &canfd_on, sizeof(canfd_on));

Todo

• disabled CAN before it is initialized by USB
• test CAN-FD frames longer than 8 bytes, right now only classic CAN is tested
• implement bootloader

Misc

• forked from: https://github.com/ucandevices/CFDC_embedded
• original project this is based on: https://ucandevices.github.io/cfuc.html
• ucan_itils: https://github.com/ucandevices/ucan_utils
• can-utils: https://github.com/linux-can/can-utils
• python-can: https://github.com/hardbyte/python-can