Question
STM32F032 CAN bus
Posted on May 18, 2018 at 12:01
Turvey.Clive.002
‌Barkin.Tyler.001
‌Hi Clive ,
I'm using the STM32F072 discovery board. In that i'm using the CAN peripherals CAN_Tx and CAN_Rx .
Below is the circuit diagram of my connection.
I'm using MCP2551 trans-receiver. when i'm trying to send the CAN frame i'm getting the ''bit dominant error''.
I have monitored the CAN_ESR (CAN error status register) in that Last error code (LEC) i got the count 101=> which indicates the ''Bit dominant error''. I'm not understanding the what goes wrong , i have shared the code also please help me if any body is having the solution for this.
CODE
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/* Includes ------------------------------------------------------------------*/
&sharpinclude ''stm32f0xx.h''/** @addtogroup STM32F0_Snippets
* @{ *//* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/&sharpdefine CMD_TOGGLE (0xDA)&sharpdefine CAN_ID_MASK (0xFF70U)&sharpdefine CAN_ID1 (0x651U)&sharpdefine CAN_ID2 (0x652U)&sharpdefine FILTER_LIST (1) /* 0: filter mode = identifier mask, 1: filter mode = identifier list *//* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*//* Private function prototypes -----------------------------------------------*/void Configure_GPIO_LED(void);void Configure_GPIO_CAN(void);void Configure_CAN(void);void Configure_GPIO_Button(void);void Configure_EXTI(void);/* Private functions ---------------------------------------------------------*/
/**
* @brief Main program. * @param None * @retval None */int main(void){Configure_GPIO_LED();
Configure_GPIO_CAN(); Configure_CAN(); Configure_GPIO_Button(); Configure_EXTI();/* Infinite loop */
while (1) { }}__INLINE void Configure_GPIO_LED(void){ /* Enable the peripheral clock of GPIOC */ RCC->AHBENR |= RCC_AHBENR_GPIOCEN; /* Select output mode (01) on PC8 and PC9 */ GPIOC->MODER = (GPIOC->MODER & ~(GPIO_MODER_MODER8 | GPIO_MODER_MODER9)) \ | (GPIO_MODER_MODER8_0 | GPIO_MODER_MODER9_0);}__INLINE void Configure_GPIO_CAN(void){ /* Enable the peripheral clock of GPIOA */ RCC->AHBENR |= RCC_AHBENR_GPIOAEN; /* GPIO configuration for CAN signals */ /* (1) Select AF mode (10) on PA11 and PA12 */ /* (2) AF4 for CAN signals */ GPIOA->MODER = (GPIOA->MODER & ~(GPIO_MODER_MODER11 | GPIO_MODER_MODER12))\ | (GPIO_MODER_MODER11_1 | GPIO_MODER_MODER12_1); /* (1) */ GPIOA->AFR[1] = (GPIOA->AFR[1] &~ (GPIO_AFRH_AFRH3 | GPIO_AFRH_AFRH4))\ | (4 << (3 * 4)) | (4 << (4 * 4)); /* (2) */}/**
* @brief This function configures CAN. * @param None * @retval None */__INLINE void Configure_CAN(void){ /* Enable the peripheral clock CAN */ RCC->APB1ENR |= RCC_APB1ENR_CANEN; CAN->MCR |= CAN_MCR_INRQ; /* (1) */ while((CAN->MSR & CAN_MSR_INAK)!=CAN_MSR_INAK) /* (2) */ { /* add time out here for a robust application */ } CAN->MCR &=~ CAN_MCR_SLEEP; /* (3) */ // CAN->BTR |= CAN_BTR_LBKM | 2 << 20 | 3 << 16 | 5 << 0; /* (4) */ CAN->BTR |= 2 << 20 | 3 << 16 | 5 << 0; /* (4) */ CAN->MCR &=~ CAN_MCR_INRQ; /* (5) */ while((CAN->MSR & CAN_MSR_INAK)==CAN_MSR_INAK) /* (6) */ { /* add time out here for a robust application */ } CAN->FMR = CAN_FMR_FINIT; /* (7) */ CAN->FA1R = CAN_FA1R_FACT0; /* (8) */&sharpif (FILTER_LIST) CAN->FM1R = CAN_FM1R_FBM0; /* (9) */ CAN->sFilterRegister[0].FR1 = CAN_ID2 << 5 | CAN_ID1 << (16+5); /* (10) */ &sharpelse CAN->sFilterRegister[0].FR1 = CAN_ID1 << 5 | CAN_ID_MASK << 16; /* (11) */&sharpendif /* FILTER_LIST */ CAN->FMR &=~ CAN_FMR_FINIT; /* (12) */ CAN->IER |= CAN_IER_FMPIE0; /* (13) */ /* Configure IT */ /* (14) Set priority for CAN_IRQn */ /* (15) Enable CAN_IRQn */ NVIC_SetPriority(CEC_CAN_IRQn, 0); /* (16) */ NVIC_EnableIRQ(CEC_CAN_IRQn); /* (17) */}__INLINE void Configure_GPIO_Button(void){ /* Enable the peripheral clock of GPIOA */ RCC->AHBENR |= RCC_AHBENR_GPIOAEN; /* Select mode */ /* Select input mode (00) on PA0 */ GPIOA->MODER = (GPIOA->MODER & ~(GPIO_MODER_MODER0));}/**
* @brief This function configures EXTI. * @param None * @retval None */__INLINE void Configure_EXTI(void){ SYSCFG->EXTICR[0] = (SYSCFG->EXTICR[0] & ~SYSCFG_EXTICR1_EXTI0) | SYSCFG_EXTICR1_EXTI0_PA; /* (1) */ EXTI->IMR |= EXTI_IMR_MR0; /* (2) */ EXTI->RTSR |= EXTI_RTSR_TR0; /* (3) */ NVIC_SetPriority(EXTI0_1_IRQn, 0); /* (4) */ NVIC_EnableIRQ(EXTI0_1_IRQn); /* (5) */ }/******************************************************************************/
/* Cortex-M0 Processor Exceptions Handlers *//******************************************************************************//**
* @brief This function handles NMI exception. * @param None * @retval None */void NMI_Handler(void){}/**
* @brief This function handles Hard Fault exception. * @param None * @retval None */void HardFault_Handler(void){ /* Go to infinite loop when Hard Fault exception occurs */ while (1) { }}/**
* @brief This function handles SVCall exception. * @param None * @retval None */void SVC_Handler(void){}/**
* @brief This function handles PendSVC exception. * @param None * @retval None */void PendSV_Handler(void){}/**
* @brief This function handles SysTick Handler. * @param None * @retval None */void SysTick_Handler(void){}/** * @brief This function handles EXTI 0 1 interrupt request. * @param None * @retval None */void EXTI0_1_IRQHandler(void){ EXTI->PR |= 1; if((CAN->TSR & CAN_TSR_TME0) == CAN_TSR_TME0)/* check mailbox 0 is empty */ { CAN->sTxMailBox[0].TDTR = 1; /* fill data length = 1 */ CAN->sTxMailBox[0].TDLR = CMD_TOGGLE; /* fill 8-bit data */ CAN->sTxMailBox[0].TIR = (uint32_t)(CAN_ID1 << 21 | CAN_TI0R_TXRQ); /* fill Id field and request a transmission */ } else { CAN->TSR |= CAN_TSR_ABRQ0; /* abort transmission if not empty */ }}/**
* @brief This function handles CAN interrupt request. * @param None * @retval None */void CEC_CAN_IRQHandler(void){ uint32_t CAN_ReceiveMessage = 0;if((CAN->RF0R & CAN_RF0R_FMP0)!=0)/* check if a message is filtered and received by FIFO 0 */
{ CAN_ReceiveMessage = CAN->sFIFOMailBox[0].RDLR; /* read data */ CAN->RF0R |= CAN_RF0R_RFOM0; /* release FIFO */ if((CAN_ReceiveMessage & 0xFF) == CMD_TOGGLE) { GPIOC->ODR ^= GPIO_ODR_8; /* Toggle orange LED */ } }}/** * @} */@@@@@@@@@@null