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Erwan03
Graduate
March 25, 2024
Solved

CAN frame monitoring problem in loopback mode

  • March 25, 2024
  • 2 replies
  • 2224 views

@mƎALLEm hello again,

 

So , i am facing a problem to display the frame i am supposed to send from CAN_Tx pin in loopback mode. I am using picoscope to display.

Here is the function i wrote to configure the Header, and send the data:

void CAN_send(void)

{

char msg[50];

CAN_TxHeaderTypeDef TxHeader;

uint32_t TxMailbox;

uint8_t TxData[4] = {'T','E','S','T'};

 

TxHeader.DLC = 4; // 4 data byte

TxHeader.ExtId = 0; // Not used so far

TxHeader.IDE = CAN_ID_STD; // Standard ID

TxHeader.RTR = CAN_RTR_DATA; // Data and not remote frame

TxHeader.StdId = 0x103; // Data ID

TxHeader.TransmitGlobalTime = DISABLE;

 

if(HAL_CAN_AddTxMessage(&hcan1, &TxHeader, TxData, &TxMailbox)!=HAL_OK)

{

Error_Handler();

}

while( HAL_CAN_IsTxMessagePending(&hcan1, TxMailbox));

 

sprintf(msg, "Message transmitted\r\n");

HAL_UART_Transmit(&huart2, (uint8_t*)msg, strlen(msg), HAL_MAX_DELAY);

}

 

In the Main function, i am calling it after the HAL_CAN_Start function. The uart connexion tells me that the frame is sent but i can't see it though.

Thank you again for your precious help!

      This topic has been closed for replies.
      Best answer by mƎALLEm

      Thank you for the shared main file:

      I noticed two issues:

      In the timing configuration:

      hcan1.Init.TimeSeg1 = CAN_BS1_1TQ;
hcan1.Init.TimeSeg2 = CAN_BS2_8TQ;

      And with the filter configuration:

      canfilterconfig.FilterBank = 10;
canfilterconfig.SlaveStartFilterBank = 0;

      So try these configurations:

       hcan1.Init.TimeSeg1 = CAN_BS1_7TQ;
 hcan1.Init.TimeSeg2 = CAN_BS2_2TQ;

      and

       canfilterconfig.FilterBank = 0;
 canfilterconfig.SlaveStartFilterBank = 14;

      2 replies

      M
      mƎALLEmAnswer
      Technical Moderator
      March 25, 2024

      Thank you for the shared main file:

      I noticed two issues:

      In the timing configuration:

      hcan1.Init.TimeSeg1 = CAN_BS1_1TQ;
hcan1.Init.TimeSeg2 = CAN_BS2_8TQ;

      And with the filter configuration:

      canfilterconfig.FilterBank = 10;
canfilterconfig.SlaveStartFilterBank = 0;

      So try these configurations:

       hcan1.Init.TimeSeg1 = CAN_BS1_7TQ;
 hcan1.Init.TimeSeg2 = CAN_BS2_2TQ;

      and

       canfilterconfig.FilterBank = 0;
 canfilterconfig.SlaveStartFilterBank = 14;
      E
      Erwan03Author
      Graduate
      March 25, 2024

      Nothing changed: 

      Erwan03_0-1711377842439.png

      Let me inform you than i got it to work once but several weeks ago and when i added some structures and other functions in order to fit it into a real project then it couldn't work anymore. And the parameters you asked me to change were the same unfortunately.

      E
      Erwan03Author
      Graduate
      March 25, 2024

      Wait Wait! It works actually.

      The debug mode does not allow us to see a frame. Only run mode. Thank you for your help!

       

      Erwan03_0-1711378661796.png

       

      Have a nice day!

        M
        mƎALLEm
        Technical Moderator
        March 25, 2024
        @Erwan03 wrote:

        Wait Wait! It works actually.

        The debug mode does not allow us to see a frame. Only run mode. Thank you for your help!

         

        Erwan03_0-1711378661796.png

         

        Have a nice day!

        Nice! You're welcome :smiling_face_with_smiling_eyes: .. But still strange it could not be running in debug mode!

        Which Toolchain are you using? I will try it with a NUCLEO-F446RE board when I have one on hands.

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