Hello there
I am struggling with receiving interrupts on my microcontroller project. I am currently developing a CAN bus logging device; the following code therefore sets up the CAN peripheral in silent mode. I test my device in a CAN network with two other devices that are constantly communicating with each other. I have verified that the CAN messages appear at the CAN Rx pin of my MCU using an oscilloscope.
However, my CAN Rx interrupts won't fire. I tried some fixes from other posts, but unfortunately, neither of them worked for me.
My setup is as follows:
>> MCU: STM32L432KCU
>> CAN receiver ISO1044BD
>> Vdd = 1.8 V (the MCU and the CAN transceiver are both running on this level).
>> IDE = CubeIDE
Have any of you ever had to tackle this problem?
## Here is the can.c file that was automatically generated by the CubeIDE, in which you can see the CAN initialisation.
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file can.c
* @brief This file provides code for the configuration
* of the CAN instances.
******************************************************************************
* @attention
*
* Copyright (c) 2025 STMicroelectronics.
* All rights reserved.
*
* This software is licensed under terms that can be found in the LICENSE file
* in the root directory of this software component.
* If no LICENSE file comes with this software, it is provided AS-IS.
*
******************************************************************************
*/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "can.h"
/* USER CODE BEGIN 0 */
#include "hal_handles.h"
/* USER CODE END 0 */
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 = 5;
hcan1.Init.Mode = CAN_MODE_SILENT;
hcan1.Init.SyncJumpWidth = CAN_SJW_2TQ;
hcan1.Init.TimeSeg1 = CAN_BS1_13TQ;
hcan1.Init.TimeSeg2 = CAN_BS2_2TQ;
hcan1.Init.TimeTriggeredMode = DISABLE;
hcan1.Init.AutoBusOff = ENABLE;
hcan1.Init.AutoWakeUp = DISABLE;
hcan1.Init.AutoRetransmission = ENABLE;
hcan1.Init.ReceiveFifoLocked = DISABLE;
hcan1.Init.TransmitFifoPriority = DISABLE;
if (HAL_CAN_Init(&hcan1) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN CAN1_Init 2 */
hal_handles_setCanHandle(&hcan1);
/* USER CODE END CAN1_Init 2 */
}
void HAL_CAN_MspInit(CAN_HandleTypeDef* canHandle)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
if(canHandle->Instance==CAN1)
{
/* USER CODE BEGIN CAN1_MspInit 0 */
/* USER CODE END CAN1_MspInit 0 */
/* CAN1 clock enable */
__HAL_RCC_CAN1_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
/**CAN1 GPIO Configuration
PA11 ------> CAN1_RX
PA12 ------> CAN1_TX
*/
GPIO_InitStruct.Pin = GPIO_PIN_11|GPIO_PIN_12;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
GPIO_InitStruct.Alternate = GPIO_AF9_CAN1;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
/* CAN1 interrupt Init */
HAL_NVIC_SetPriority(CAN1_RX0_IRQn, 5, 0);
HAL_NVIC_EnableIRQ(CAN1_RX0_IRQn);
HAL_NVIC_SetPriority(CAN1_RX1_IRQn, 5, 0);
HAL_NVIC_EnableIRQ(CAN1_RX1_IRQn);
/* USER CODE BEGIN CAN1_MspInit 1 */
/* USER CODE END CAN1_MspInit 1 */
}
}
void HAL_CAN_MspDeInit(CAN_HandleTypeDef* canHandle)
{
if(canHandle->Instance==CAN1)
{
/* USER CODE BEGIN CAN1_MspDeInit 0 */
/* USER CODE END CAN1_MspDeInit 0 */
/* Peripheral clock disable */
__HAL_RCC_CAN1_CLK_DISABLE();
/**CAN1 GPIO Configuration
PA11 ------> CAN1_RX
PA12 ------> CAN1_TX
*/
HAL_GPIO_DeInit(GPIOA, GPIO_PIN_11|GPIO_PIN_12);
/* CAN1 interrupt Deinit */
HAL_NVIC_DisableIRQ(CAN1_RX0_IRQn);
HAL_NVIC_DisableIRQ(CAN1_RX1_IRQn);
/* USER CODE BEGIN CAN1_MspDeInit 1 */
/* USER CODE END CAN1_MspDeInit 1 */
}
}
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
### and here you can see, how i set up my filter (supposed to accept all filters)
static void set_filter_configuration(void)
{
CAN_FilterTypeDef filter;
filter.FilterMode = CAN_FILTERMODE_IDMASK;
filter.FilterScale = CAN_FILTERSCALE_32BIT;
filter.FilterIdHigh = 0x0000;
filter.FilterIdLow = 0x0000;
filter.FilterMaskIdHigh = 0x0000;
filter.FilterMaskIdLow = 0x0000;
filter.FilterFIFOAssignment = CAN_FILTER_FIFO0;
filter.FilterActivation = ENABLE;
filter.FilterBank = 0;
filter.SlaveStartFilterBank = 0;
HAL_CAN_ConfigFilter(hal_handles_getCanHandle(), &filter);
}
void HAL_CAN_RxFifo0MsgPendingCallback(CAN_HandleTypeDef *hcan)
{
// ... handling isr
}
void pl_can_init(void)
{
CAN_HandleTypeDef *hcan = hal_handles_getCanHandle();
// some other inits...
set_filter_configuration();
if (HAL_CAN_Start(hcan) != HAL_OK)
{
for (;;)
;
}
}
