STM32F423 bxCAN + Arduino MCP2515 — CAN reception issue

[nikhilkrn]

Hardware connection

• Node A: STM32F423RHTx, TCAN1462-Q1 transceiver, HSI→PLL→80MHz SYSCLK, 40MHz APB1, PA11/PA12
• Node B: Arduino Uno + MCP2515 breakout (8MHz xtal, onboard transceiver), mcp_can v1.5. 120Ω termination, wiring verified 
• CAN Timing (both at 500kbps)

CAN Configuration

CAN_HandleTypeDef hcan1;

/* CAN1 init function */
void MX_CAN1_Init(void)
{

  /* USER CODE BEGIN CAN1_Init 0 */

  /* USER CODE END CAN1_Init 0 */

  /* USER CODE BEGIN CAN1_Init 1 */

  /* USER CODE END CAN1_Init 1 */
  hcan1.Instance = CAN1;
  hcan1.Init.Prescaler = 8;
  hcan1.Init.Mode = CAN_MODE_NORMAL;
  hcan1.Init.SyncJumpWidth = CAN_SJW_1TQ;
  hcan1.Init.TimeSeg1 = CAN_BS1_6TQ;
  hcan1.Init.TimeSeg2 = CAN_BS2_3TQ;
  hcan1.Init.TimeTriggeredMode = DISABLE;
  hcan1.Init.AutoBusOff = DISABLE;
  hcan1.Init.AutoWakeUp = ENABLE;
  hcan1.Init.AutoRetransmission = DISABLE;
  hcan1.Init.ReceiveFifoLocked = DISABLE;
  hcan1.Init.TransmitFifoPriority = DISABLE;
  if (HAL_CAN_Init(&hcan1) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN CAN1_Init 2 */
  CAN_FilterTypeDef canfilterconfig;

  canfilterconfig.FilterBank = 0;
  canfilterconfig.FilterMode = CAN_FILTERMODE_IDMASK;
  canfilterconfig.FilterScale = CAN_FILTERSCALE_32BIT;
  canfilterconfig.FilterIdHigh = 0x0000;
  canfilterconfig.FilterIdLow = 0x0000;
  canfilterconfig.FilterMaskIdHigh = 0x0000;
  canfilterconfig.FilterMaskIdLow = 0x0000;
  canfilterconfig.FilterFIFOAssignment = CAN_RX_FIFO0;
  canfilterconfig.FilterActivation = CAN_FILTER_ENABLE;
  canfilterconfig.SlaveStartFilterBank = 14;

  if (HAL_CAN_ConfigFilter(&hcan1, &canfilterconfig) != HAL_OK)
  {
    Error_Handler();
  }

  /* USER CODE END CAN1_Init 2 */

}

Notification is also enabled. 

  if (HAL_CAN_ActivateNotification(&hcan1, CAN_IT_RX_FIFO0_MSG_PENDING) != HAL_OK)
  {
      Error_Handler();
  }

Callback function

CAN_RxHeaderTypeDef gRxHeader;
uint8_t             gRxData[8];

void HAL_CAN_RxFifo0MsgPendingCallback(CAN_HandleTypeDef *hcan)
{
	printf("Hi from CB\r\n");
        if (HAL_CAN_GetRxMessage(&hcan1, CAN_RX_FIFO0, &gRxHeader, gRxData) == HAL_OK){
                printf("ID: 0x%03lX  DLC: %lu  Data:", gRxHeader.StdId, gRxHeader.DLC);
                for (uint8_t i = 0; i < gRxHeader.DLC; i++){
                        printf(" %02X", gRxData[i]);
                }
                printf("\r\n");
        }
}

What Works

• STM32 → Arduino: Arduino serial monitor shows received frames every 1 second
• STM32 Loopback mode: receives own frames internally
• STM32 register dump: IER=0x02 (FMPIE0 armed), MSR shows normal mode, filter active

What Doesn't Work

• Arduino → STM32: RF0R.FMP permanently 0, REC=0, interrupt never fires
• Arduino sendMsgBuf returns CAN_SENDMSGTIMEOUT (7), EFLG=0x15 (TXEP+TXWAR+EWARN)
• STM32's own TX frames show ACK Error (LEC=0x3) and TERR0=1 despite Arduino claiming to receive them — ACK contradiction

I have tried changing the filter configuration still that didn't worked.

[mƎALLEm]

Hello @nikhilkrn and welcome to the ST community,

---

First thing to check is your hardware: the wiring: especially the bad contacts.

Second issue: 

---

@nikhilkrn wrote:

• Node A: STM32F423RHTx, TCAN1462-Q1 transceiver, HSI→PLL→80MHz SYSCLK, 40MHz APB1, PA11/PA12

---

You should avoid using HSI for CAN communication in Normal mode. Use a crystal or you can face comm issues. Please refer to these articles:

CAN reception issues: Reasons and general troubleshooting

Using CAN (bxCAN) in Normal mode with STM32 microcontrollers (Part 1)

Using CAN (bxCAN) in Normal mode with STM32 microcontrollers (Part 2)

Hope that helps.

[nikhilkrn]

Hi @mƎALLEm , 

Thanks for the response. I've since switched to HSE (25 MHz crystal on PH0/PH1 with PLL: M=12, N=96, P=2 → SYSCLK=100 MHz, APB1=50 MHz, CAN Prescaler=10) — no more HSI.
After all fixes, both nodes confirmed at exactly 500 kbps. STM32 → Arduino works reliably. Register-level checks on the STM32 side show:

• IER = 0x02 
• MSR = 0x00000C08 (INAK=0, SLAK=0 — normal mode)
• FA1R confirms filter bank 0 active (catch-all 32-bit mask)
• Interrupt chain verified: NVIC enabled, IRQHandler wired, notification activated
• ESR = 0x00000000 consistently: REC=0, TEC=0 — no errors, but also no frames.

I have a doubt that if Transmission works then it shouldn't be hardware issue?

I have checked the articles as well still facing the same issue. 

[mƎALLEm]

1- Please share your complete project

2- What are the power supply voltage levels of the TCAN1462-Q1 transceiver: VCC and VIO?

[nikhilkrn]

Hi,
I have attached the project file.

[mƎALLEm]

---

@nikhilkrn wrote:

Hi,
I have attached the project file.

---

Thank you for the sharing but you didn't answer my second question.

[nikhilkrn]

Hi,
VIO: 3V3
VCC: 5V
It's a custom board with stm32f423RHT6 mcu. I have tried with other transiver as well separately but still issue is same.
let me know if you need any more information.
Thanks!!

[mƎALLEm]

+ 

You are still pointing to HSI as clock source:

Even though the clock config in the main configures HSE as clock source for PLL:

  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLM = 12;
  RCC_OscInitStruct.PLL.PLLN = 96;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }

So there is a mismatch between the ioc file and main. You need to regenerate the code with HSE selected as source clock in the ioc file and retest.

[Ozone]

Assuming you don't have a protocol analyser something similiar, have you tried a lower bitrate ?

[mƎALLEm]

+

There is a mismatch in the filter config in tha attached project:

  canfilterconfig.FilterBank = 0;
  canfilterconfig.FilterMode = CAN_FILTERMODE_IDMASK;
  canfilterconfig.FilterScale = CAN_FILTERSCALE_32BIT;
  canfilterconfig.FilterIdHigh = 0x0F6<<5;
  canfilterconfig.FilterIdLow = 0x0000;
  canfilterconfig.FilterMaskIdHigh = 0x0F6<<5;
  canfilterconfig.FilterMaskIdLow = 0x0000;
  canfilterconfig.FilterFIFOAssignment = CAN_RX_FIFO0;
  canfilterconfig.FilterActivation = CAN_FILTER_ENABLE;
  canfilterconfig.SlaveStartFilterBank = 14;

And what you have shared in the first post: 

  canfilterconfig.FilterBank = 0;
  canfilterconfig.FilterMode = CAN_FILTERMODE_IDMASK;
  canfilterconfig.FilterScale = CAN_FILTERSCALE_32BIT;
  canfilterconfig.FilterIdHigh = 0x0000;
  canfilterconfig.FilterIdLow = 0x0000;
  canfilterconfig.FilterMaskIdHigh = 0x0000;
  canfilterconfig.FilterMaskIdLow = 0x0000;
  canfilterconfig.FilterFIFOAssignment = CAN_RX_FIFO0;
  canfilterconfig.FilterActivation = CAN_FILTER_ENABLE;
  canfilterconfig.SlaveStartFilterBank = 14;

 So please restore the first filters config:

  canfilterconfig.FilterMode = CAN_FILTERMODE_IDMASK;
  canfilterconfig.FilterScale = CAN_FILTERSCALE_32BIT;
  canfilterconfig.FilterIdHigh = 0x0000;
  canfilterconfig.FilterIdLow = 0x0000;
  canfilterconfig.FilterMaskIdHigh = 0x0000;
  canfilterconfig.FilterMaskIdLow = 0x0000;

Please don't post many configuration for the same issue. So it muddies the waters.

So what I suggest is to provide a complete project on which you did the final test with:

and