Edit: HAL_CAN_Start() and configuring the CAN filter correctly fixed it.
Hi, I am trying to read CAN messages sent by a device, but are not able to.
Hardware setup should be correct, my setup works when testing with a program using mBed OS, messages are correctly received.
Some notes:
- The messages are specified to be CAN2.0B, standard frame format, baud 250kbps, Sampling point 70%, SJW 2 Tq.
- CAN1 is used configured to PD0 and PD1.
- UART and GPIO works as expected.
- I used http://www.bittiming.can-wiki.info/ for bit timing, BTR register is set to 0x0149000b which I have verified in the debugger.
- HAL_CAN_GetRxFifoFillLevel() returns 0 and HAL_CAN_GetRxMessage returns no message.
- The clocks is configured to the default that CubeMX set when initializing default settings for peripherals, APB1 clock is set to 48 MHz, which is used as basis for the CAN bit timings.
- I have not configured any filter.
Code(irrelevant code removed, msp at the end):
#include "main.h"
#include <stdio.h>
CAN_HandleTypeDef hcan1;
UART_HandleTypeDef huart3;
CAN_TxHeaderTypeDef TxHeader;
CAN_RxHeaderTypeDef RxHeader;
uint8_t TxData[8];
uint8_t RxData[8];
uint32_t TxMailbox;
char msg[50];
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_USART3_UART_Init(void);
static void MX_CAN1_Init(void);
int main(void)
{
HAL_Init();
SystemClock_Config();
MX_GPIO_Init();
MX_USART3_UART_Init();
MX_CAN1_Init();
uint8_t TestData[7];
while (1)
{
sprintf(msg,"Waiting for message\r\n");
HAL_UART_Transmit(&huart3,(uint8_t*)msg,sizeof(msg),HAL_MAX_DELAY);
if (HAL_CAN_GetRxFifoFillLevel(&hcan1, CAN_RX_FIFO0) > 0)
{
HAL_CAN_GetRxMessage(&hcan1, CAN_RX_FIFO0, &RxHeader, TestData);
HAL_UART_Transmit(&huart3, "Can Message recieved\n\r", 22, 10);
}
HAL_CAN_GetRxMessage(&hcan1, CAN_RX_FIFO0, &RxHeader, TestData);
sprintf(msg,"Message: %x\r\n", TestData[0]);
HAL_UART_Transmit(&huart3,(uint8_t*)msg,sizeof(msg),HAL_MAX_DELAY);
HAL_Delay(500);
}
}
void SystemClock_Config(void)
{
RCC_OscInitTypeDef RCC_OscInitStruct = {0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
RCC_PeriphCLKInitTypeDef PeriphClkInitStruct = {0};
HAL_PWR_EnableBkUpAccess();
__HAL_RCC_PWR_CLK_ENABLE();
__HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE3);
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
RCC_OscInitStruct.HSEState = RCC_HSE_BYPASS;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
RCC_OscInitStruct.PLL.PLLM = 4;
RCC_OscInitStruct.PLL.PLLN = 96;
RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
RCC_OscInitStruct.PLL.PLLQ = 4;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
Error_Handler();
}
if (HAL_PWREx_EnableOverDrive() != HAL_OK)
{
Error_Handler();
}
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
|RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_3) != HAL_OK)
{
Error_Handler();
}
PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_USART3|RCC_PERIPHCLK_CLK48;
PeriphClkInitStruct.Usart3ClockSelection = RCC_USART3CLKSOURCE_PCLK1;
PeriphClkInitStruct.Clk48ClockSelection = RCC_CLK48SOURCE_PLL;
if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct) != HAL_OK)
{
Error_Handler();
}
}
static void MX_CAN1_Init(void)
{
hcan1.Instance = CAN1;
hcan1.Init.Prescaler = 12;
hcan1.Init.Mode = CAN_MODE_NORMAL;
hcan1.Init.SyncJumpWidth = CAN_SJW_2TQ;
hcan1.Init.TimeSeg1 = CAN_BS1_10TQ;
hcan1.Init.TimeSeg2 = CAN_BS2_5TQ;
hcan1.Init.TimeTriggeredMode = DISABLE;
hcan1.Init.AutoBusOff = DISABLE;
hcan1.Init.AutoWakeUp = DISABLE;
hcan1.Init.AutoRetransmission = DISABLE;
hcan1.Init.ReceiveFifoLocked = DISABLE;
hcan1.Init.TransmitFifoPriority = DISABLE;
if (HAL_CAN_Init(&hcan1) != HAL_OK)
{
Error_Handler();
}
}
static void MX_GPIO_Init(void)
{
lots of code
}
void Error_Handler(void)
{
}
/* hal_msp.c */
void HAL_CAN_MspInit(CAN_HandleTypeDef* hcan)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
if(hcan->Instance==CAN1)
{
__HAL_RCC_CAN1_CLK_ENABLE();
__HAL_RCC_GPIOD_CLK_ENABLE();
GPIO_InitStruct.Pin = GPIO_PIN_0|GPIO_PIN_1;
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(GPIOD, &GPIO_InitStruct);
}
}
