in the event of a transmission failure, the function does not return (as expected).

[ShiPC123]

I am using an STM32G431 MCU. Currently, it can normally transmit and receive CAN data; however, in the event of a transmission failure, the function does not return (as expected).

As shown in the figure, I disconnected the CAN_H cable, but the system still indicates normal transmission.

this is my code

[ShiPC123]

If I set settings.mEnableRetransmission to TRUE ,I can confirm that the system will indeed resend the data that failed to be sent last time.

[nopnop2002]

Known issues

If we use a 3.3V transceiver such as the VP230, transmission will not work, only reception will work.
The 5V transceiver works fine for both transmission and reception.
I don't know the reason. Please let me know if you find out the reason.

If the transmission fails, these are the possible causes.

• There is no receiving app on CanBus.
• The speed does not match the receiver.
• There is no terminating resistor on the CanBus.
• There are three terminating resistors on the CanBus.
• The resistance value of the terminating resistor is incorrect.
• 3.3V transceiver and 5V transceiver are mixed.
  Use +1V Ground Shift using Split Termination.
  Check out Figure 7 here.
• Stub length in CAN bus is too long.
  ISO11898 Standard specifies a maximum bus length of 40m and maximum stub length of 0.3m at 1Mbps.
  See here.
• Noise effects.
  It occurs when the wire cable is thin or wire cable is crossing.
  It is preferable to use wires that are noise-proof.

I changed the single wire to twisted wire. It's fixed.

[ShiPC123]

Perhaps my explanation is not clear. Currently, I can successfully receive and transmit data. However, if I disconnect CAN_L or CAN_H, when the condition if (CAN_RX_msg.type == CANFDMessage::CAN_DATA) {} is checked, it will not return any error code, but only return the communication success parameter 0.

[nopnop2002]

Thank you for the explanation.

I'm moving tomorrow.

I won't have internet access while I'm moving.

I still can't connect to the internet at my new location.

All of my development equipment is in moving boxes.

I'll look into it once the move is complete and everything is set up.