Posted on May 17, 2011 at 13:04I have a problem in setting up CAN in normal mode. It is working well while in LoopBack, but not working when i change it to Normal mode.
My settings are given below..Please Let me know if anyone detect anything missing from this..
/* RCC setup */
RCC_DeInit();
/* Enable HSE */
RCC_HSEConfig(RCC_HSE_ON);
/* Wait till HSE is ready */
HSEStartUpStatus = RCC_WaitForHSEStartUp();
if(HSEStartUpStatus == SUCCESS)
{
/* HCLK = SYSCLK */
RCC_HCLKConfig(RCC_SYSCLK_Div1);
/* PCLK2 = HCLK */
RCC_PCLK2Config(RCC_HCLK_Div1);
/* PCLK1 = HCLK/2 */
RCC_PCLK1Config(RCC_HCLK_Div1);
/* Enable Prefetch Buffer */
FLASH_PrefetchBufferCmd(FLASH_PrefetchBuffer_Enable);
/* Select HSE as system clock source */
RCC_SYSCLKConfig(RCC_SYSCLKSource_HSE);
/* Wait till HSE is used as system clock source */
while(RCC_GetSYSCLKSource() != 0x04)
{
}
}
/* GPIOA and GPIOC clock enable */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_GPIOC | RCC_APB2Periph_USART1 | RCC_APB2Periph_AFIO, ENABLE);
/* CAN Periph clock enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN, ENABLE);
/* GPIO setup */
GPIO_PinRemapConfig(GPIO_Remap1_CAN, ENABLE);// for remapping to PB8 & PB9
/* Configure CAN pin: RX */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
GPIO_Init(GPIOB, &GPIO_InitStructure);
/* Configure CAN pin: TX */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_Init(GPIOB, &GPIO_InitStructure);
/* NVIC interrupt setup*/
NVIC_InitStructure.NVIC_IRQChannel=USB_LP_CAN_RX0_IRQChannel;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
/* CAN setup and Transmit*/
// CAN register init
CAN_DeInit();
CAN_StructInit(&CAN_InitStructure);
// CAN filter init
CAN_FilterInitStructure.CAN_FilterNumber=1;
CAN_FilterInitStructure.CAN_FilterMode=CAN_FilterMode_IdMask;
CAN_FilterInitStructure.CAN_FilterScale=CAN_FilterScale_32bit;
CAN_FilterInitStructure.CAN_FilterIdHigh=0x0000;
CAN_FilterInitStructure.CAN_FilterIdLow=0x0000;
CAN_FilterInitStructure.CAN_FilterMaskIdHigh=0x0000;
CAN_FilterInitStructure.CAN_FilterMaskIdLow=0x0000;
CAN_FilterInitStructure.CAN_FilterFIFOAssignment=CAN_FIFO0;
CAN_FilterInitStructure.CAN_FilterActivation=ENABLE;
CAN_FilterInit(&CAN_FilterInitStructure);
// CAN cell init
CAN_InitStructure.CAN_TTCM=DISABLE;
CAN_InitStructure.CAN_ABOM=DISABLE;
CAN_InitStructure.CAN_AWUM=DISABLE;
CAN_InitStructure.CAN_NART=DISABLE;
CAN_InitStructure.CAN_RFLM=DISABLE;
CAN_InitStructure.CAN_TXFP=DISABLE;
CAN_InitStructure.CAN_Mode=CAN_Mode_Normal;//CAN_Mode_LoopBack;//
CAN_InitStructure.CAN_SJW=CAN_SJW_1tq;
CAN_InitStructure.CAN_BS1=CAN_BS1_8tq;
CAN_InitStructure.CAN_BS2=CAN_BS2_7tq;
CAN_InitStructure.CAN_Prescaler=2;// 8 MHz - (8/16)/250000
status=CAN_Init(&CAN_InitStructure);
if (status==CANINITOK)
{
/* CAN FIFO0 message pending interrupt enable */
CAN_ITConfig(CAN_IT_FMP0, ENABLE);
/* transmit 1 message */
TxMessage.StdId= 0x63A;
TxMessage.ExtId=0x200A;
TxMessage.IDE=CAN_ID_EXT;
TxMessage.RTR=CAN_RTR_DATA;
TxMessage.DLC=3;
TxMessage.Data[0]=0x00;
TxMessage.Data[1]=0xEE;
TxMessage.Data[2]=0x00;
ret=CAN_Transmit(&TxMessage);
}
/* CAN Receive */
void USB_LP_CAN_RX0_IRQHandler(void)
{
CanRxMsg RxMessage;
RxMessage.StdId=0x00;
RxMessage.ExtId=0x00;
RxMessage.IDE=0;
RxMessage.DLC=0;
RxMessage.FMI=0;
RxMessage.Data[0]=0x00;
RxMessage.Data[1]=0x00;
RxMessage.Data[2]=0x00;
CAN_Receive(CAN_FIFO0, &RxMessage);
}
