Tutorial — CAN 2.0B with SocketCAN¶

RPBridge exposes CAN via a gs_usb-compatible vendor interface. The mainline drivers/net/can/usb/gs_usb.ko driver binds it automatically on Linux ≥ 5.14, so this tutorial assumes nothing RPBridge-specific beyond the device being plugged in.

1. Confirm the netdev¶

ip -br link show type can
# can0             DOWN           ...

2. Configure bitrate and bring up¶

sudo ip link set can0 type can bitrate 500000 sample-point 0.875
sudo ip link set can0 up
ip -br link show can0
# can0             UNKNOWN        ...

3. Transmit and receive¶

candump can0 &
cansend can0 123#DEADBEEFCAFE0042
# can0  123   [7]  DE AD BE EF CA FE 00

4. Generate and dump traffic¶

cangen can0 -g 20 -n 500 -I i -L r &    # 500 frames, 20 ms apart
candump -ta can0 > capture.log

5. Stats and error counters¶

ip -s -s link show can0
# RX errors, TX errors, bus-off counters, etc.

6. Supported bitrates¶

Bitrate	Sample point	Notes
125 kbit/s	87.5 %	Long-link-friendly.
250 kbit/s	87.5 %	Industrial default.
500 kbit/s	80 %	Automotive default.
1 Mbit/s	75 %	Requires clean wiring + short stubs.

CAN-FD is not supported in rev-B. can2040 is a classic CAN 2.0B controller; a future hardware revision could add an external MCP2518FD over SPI if FD becomes a requirement.