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themole
themole
Associate II
Jul 27, 2018 12:10 PM UTC
Question

Cannot Trasmit messages because CAN is always in state HAL_CAN_STATE_LISTENING?

Currently I'm trying to get CAN up and running on a STM32F469NIH6 based Board using the CubeMX libraries.

Unfortunately, the documentation of the new HAL_CAN driver is very limited. I found an example in STM32Cube_FW_L4_V1.12.0\Projects\STM32L476G-EVAL\Examples\CAN\CAN_Networking\Src\main.c, but even with identical code (except the clock settings), it is not working, because the frame I added with HAL_CAN_AddTxMessage(&hcan1, &txHeader, data, &txMailbox) is not being sent, possibly because of the HAL_CAN_STATE_LISTENING.

My RX and TX lines (to the CAN-Transceiver) are both in HIGH-State (3.3V) and they keep being there when trying to transmit. CAN_H and CAN_L itself is in High-Z state, both lines are around 2V, Vdiff = 0V

Is there anything I can do wrong? Any suggestions how to debug this down to the problem?

      This topic has been closed for replies.

      5 replies

      T J
      T J
      Senior III
      Jul 27, 2018 12:15 PM UTC

      Are you running a line driver with a terminator ?

      is there another device on the canBus ?

      themole
      themoleAuthor
      Associate II
      Jul 27, 2018 12:18 PM UTC

      Yes, both ends are terminated with 120 Ohms and I run with a ISO1050 Transceiver from Texas.

      Yes, there is another devices, that sends something when I switch the system on.

      I have some very old firmware running on that board (using the old ST Standard Libraries), that where able to send something.

      T J
      T J
      Senior III
      Jul 27, 2018 12:47 PM UTC

      I use this method to transmit.. checking all three mailboxes manually.

      if ((CAN->TSR & CAN_TSR_TME0) == CAN_TSR_TME0) // (1) 
{ 
 CAN->sTxMailBox[0].TDTR = canTxMsgLength[canTxMsgOUT]; // (2) length
 CAN->sTxMailBox[0].TDLR = canTxMsgBottomWord[canTxMsgOUT]; // (3) 4bytes
 CAN->sTxMailBox[0].TDHR = canTxMsgTopWord[canTxMsgOUT]; // (3) 4bytes
 CAN->sTxMailBox[0].TIR = ((uint32_t)canTxMsgID[canTxMsgOUT] << 21 | CAN_TI0R_TXRQ); // (4) // send it now if the line is idle
}
 
if ((CAN->TSR & CAN_TSR_TME1) == CAN_TSR_TME1) // (1) 
if ((CAN->TSR & CAN_TSR_TME2) == CAN_TSR_TME2) // (1)

      AlexF
      AlexF
      Associate
      Sep 20, 2018 7:26 AM UTC

      I have the same problem with my STM32F437ZI

      @themole cuold you solve it?

      Can somebody solve the topic with the HAL interface?

      Bertrand1
      Bertrand1
      Senior
      Sep 24, 2018 11:13 AM UTC

      I have some time the same probleme. It works for a long time after but some times, Tx buffers become full. After a reset, all is working fine without any change in term of hardware. So I should solve this issue with software.

      I check if tx mailbox are full with HAL_CAN_GetTxMailboxesFreeLevel(pcan);

      If not, I clear wiht this HAL_CAN_AbortTxRequest(pcan, 0); HAL_CAN_AbortTxRequest(pcan, 1); HAL_CAN_AbortTxRequest(pcan, 2); but it not solved or partialy ( the fault occurence is less)

      The fact that the state in HAL_CAN_SATE_LISTENING seems to not be the issue.

      Thanks for your advise.

      Bertrand

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