CAN Controller TX does not show signs of life

[tyler2]

Posted on January 24, 2018 at 03:15

Can_TX is showing no activity. I can't figure out what I am doing wrong. 

I've set up the project with STMCubeMX to use CAN1 on PD0 and PD1. When I attempt to transmit there is no signs of life on the TX pin. Using the STM32F4Discovery right now. 

/**

****************************************************************************** * File Name : main.c * Description : Main program body ****************************************************************************** * * COPYRIGHT(c) 2018 STMicroelectronics * * Redistribution and use in source and binary forms, with or without modification, * are permitted provided that the following conditions are met: * 1. Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * 3. Neither the name of STMicroelectronics nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 'AS IS' * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************** *//* Includes ------------------------------------------------------------------*/&sharpinclude 'stm32f4xx_hal.h'&sharpinclude 'can.h'&sharpinclude 'gpio.h'

/* USER CODE BEGIN Includes */

/* USER CODE END Includes */

/* Private variables ---------------------------------------------------------*/

/* USER CODE BEGIN PV */

/* Private variables ---------------------------------------------------------*/CanTxMsgTypeDef TxM;CanRxMsgTypeDef RxM;CAN_FilterConfTypeDef sFilterConfig;/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/

void SystemClock_Config(void);

/* USER CODE BEGIN PFP */

/* Private function prototypes -----------------------------------------------*/

/* USER CODE END PFP */

/* USER CODE BEGIN 0 */

/* USER CODE END 0 */

int main(void)

{

/* USER CODE BEGIN 1 */

/* USER CODE END 1 */

/* MCU Configuration----------------------------------------------------------*/

/* Reset of all peripherals, Initializes the Flash interface and the Systick. */

HAL_Init();

/* Configure the system clock */

SystemClock_Config();

/* Initialize all configured peripherals */

MX_GPIO_Init(); MX_CAN1_Init();

/* USER CODE BEGIN 2 */

/* USER CODE END 2 */

/* Infinite loop */

/* USER CODE BEGIN WHILE */ HAL_GPIO_WritePin(GPIOD, GPIO_PIN_12, GPIO_PIN_SET); HAL_GPIO_WritePin(GPIOD, GPIO_PIN_13, GPIO_PIN_RESET); HAL_GPIO_WritePin(GPIOD, GPIO_PIN_14, GPIO_PIN_SET); HAL_GPIO_WritePin(GPIOD, GPIO_PIN_15, GPIO_PIN_RESET); hcan1.pTxMsg = &TxM; hcan1.pRxMsg = &RxM; hcan1.pTxMsg->StdId=0x201; hcan1.pTxMsg->IDE=CAN_ID_STD; hcan1.pTxMsg->RTR=CAN_RTR_DATA; hcan1.pTxMsg->DLC=8; sFilterConfig.FilterActivation = ENABLE; sFilterConfig.FilterNumber = 0; sFilterConfig.FilterMode = CAN_FILTERMODE_IDMASK; sFilterConfig.FilterScale = CAN_FILTERSCALE_32BIT; sFilterConfig.FilterIdHigh = 0x245<<5; sFilterConfig.FilterIdLow = 0; sFilterConfig.FilterMaskIdHigh = 0; sFilterConfig.FilterMaskIdLow = 0; sFilterConfig.FilterFIFOAssignment = 0; sFilterConfig.BankNumber = 14; HAL_CAN_ConfigFilter(&hcan1, &sFilterConfig); while (1) { /* USER CODE END WHILE */

/* USER CODE BEGIN 3 */

HAL_GPIO_WritePin(GPIOD, GPIO_PIN_12, GPIO_PIN_RESET); HAL_GPIO_WritePin(GPIOD, GPIO_PIN_13, GPIO_PIN_RESET); HAL_GPIO_WritePin(GPIOD, GPIO_PIN_14, GPIO_PIN_RESET); HAL_GPIO_WritePin(GPIOD, GPIO_PIN_15, GPIO_PIN_RESET); HAL_Delay(250); //HAL_CAN_Transmit(&hcan1,1000); HAL_GPIO_WritePin(GPIOD, GPIO_PIN_12, GPIO_PIN_SET); HAL_GPIO_WritePin(GPIOD, GPIO_PIN_13, GPIO_PIN_SET); HAL_GPIO_WritePin(GPIOD, GPIO_PIN_14, GPIO_PIN_SET); HAL_GPIO_WritePin(GPIOD, GPIO_PIN_15, GPIO_PIN_SET); HAL_Delay(250); } /* USER CODE END 3 */

}

/** System Clock Configuration

*/void SystemClock_Config(void){

RCC_OscInitTypeDef RCC_OscInitStruct;

RCC_ClkInitTypeDef RCC_ClkInitStruct;

__HAL_RCC_PWR_CLK_ENABLE();

__HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

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 = 4; RCC_OscInitStruct.PLL.PLLN = 168; RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2; RCC_OscInitStruct.PLL.PLLQ = 7; HAL_RCC_OscConfig(&RCC_OscInitStruct);

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_DIV4; RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2; HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5);

HAL_SYSTICK_Config(HAL_RCC_GetHCLKFreq()/1000);

HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);

/* SysTick_IRQn interrupt configuration */

HAL_NVIC_SetPriority(SysTick_IRQn, 0, 0);}

/* USER CODE BEGIN 4 */

/* USER CODE END 4 */

&sharpifdef USE_FULL_ASSERT

/**

* @brief Reports the name of the source file and the source line number * where the assert_param error has occurred. * @param file: pointer to the source file name * @param line: assert_param error line source number * @retval None */void assert_failed(uint8_t* file, uint32_t line){ /* USER CODE BEGIN 6 */ /* User can add his own implementation to report the file name and line number, ex: printf('Wrong parameters value: file %s on line %d\r\n', file, line) */ /* USER CODE END 6 */

}

&sharpendif

/**

* @} */

/**

* @}*/

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

#can-programming

[Tesla DeLorean]

Posted on January 24, 2018 at 03:45

Probably looking for signal on the RX side, and acknowledgement from the other end.

Perhaps look at the error thrown by 

HAL_CAN_Transmit()

Might try loop-back mode and see if there is any bleed-thru on the TX pin.

[tyler2]

Posted on January 25, 2018 at 03:36

I went from STM32Cube_FW_F4_V1.18.0 to STM32Cube_FW_F4_V1.19.0 and I'm having a little more luck. TX and RX just spit identical garbage data when I try to transmit though. I'm not 100% sure what that is about. 

https://imgur.com/a/t66v7

[Tesla DeLorean]

Posted on January 25, 2018 at 05:12

The transceiver drives the CAN_TX on the bus, and sees what level is on the bus via CAN_RX, you'd expect to see the same signal if it has been successful.

[tyler2]

Posted on January 25, 2018 at 18:52

Ah ok that makes sense then. I ended up getting it working last night after many attempts. Two notes from my headaches :

1) I was using the wrong clock speed when calculating the settings for the CAN bus, it was conflicting with the other CAN nodes as they didn't have the same baud rate. The system clock was at 168MHz but the clock for the CAN bus was at 42MHz, I didn't notice this right away. 

2) The CAN driver wants to be connected to the transceiver or it will not even get through initialization, I was trying to break the system up into discrete parts to figure out what part was failing but it was causing more issues.