最近在学习stm32,源代码用的原子哥的,前几天将代码下到板子之后通信毫无问题,但是昨天重新改了程序再下载到芯片之后发现无法通信了。随后将代码改回原样也不行了...
代码如下:
原子哥的代码基本没改,初始化为只接收标准ID:0x10发来的报文,中断优先级:抢占0,子0
u8 CAN_Mode_Init(u8 tsjw,u8 tbs2,u8 tbs1,u16 brp,u8 mode)
{
GPIO_InitTypeDef GPIO_InitStructure;
CAN_InitTypeDef CAN_InitStructure;
CAN_FilterInitTypeDef CAN_FilterInitStructure;
#if CAN_RX0_INT_ENABLE
NVIC_InitTypeDef NVIC_InitStructure;
#endif
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);//使能PORTD时钟
RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN1, ENABLE);//使能CAN1时钟
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //复用推挽
GPIO_Init(GPIOA, &GPIO_InitStructure); //初始化IO
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;//上拉输入
GPIO_Init(GPIOA, &GPIO_InitStructure);//初始化IO
//GPIO_PinRemapConfig(GPIO_Remap2_CAN1 , ENABLE);
CAN_DeInit(CAN1);
//CAN单元设置
CAN_InitStructure.CAN_TTCM=DISABLE; //非时间触发通信模式 //
CAN_InitStructure.CAN_ABOM=DISABLE; //软件自动离线管理 //
CAN_InitStructure.CAN_AWUM=DISABLE; //睡眠模式通过软件唤醒(清除CAN->MCR的SLEEP位)//
CAN_InitStructure.CAN_NART=ENABLE; //报文自动传送 //
CAN_InitStructure.CAN_RFLM=DISABLE; //报文不锁定,新的覆盖旧的 //
CAN_InitStructure.CAN_TXFP=DISABLE; //优先级由报文标识符决定 //
CAN_InitStructure.CAN_Mode= mode; //模式设置: mode:0,普通模式;1,回环模式; //
//设置波特率
CAN_InitStructure.CAN_SJW=tsjw; //重新同步跳跃宽度(Tsjw)为tsjw+1个时间单位 CAN_SJW_1tq CAN_SJW_2tq CAN_SJW_3tq CAN_SJW_4tq
CAN_InitStructure.CAN_BS1=tbs1; //Tbs1=tbs1+1个时间单位CAN_BS1_1tq ~CAN_BS1_16tq
CAN_InitStructure.CAN_BS2=tbs2; //Tbs2=tbs2+1个时间单位CAN_BS2_1tq ~ CAN_BS2_8tq
CAN_InitStructure.CAN_Prescaler=brp; //分频系数(Fdiv)为brp+1 //
CAN_Init(CAN1, &CAN_InitStructure); // 初始化CAN1
CAN_FilterInitStructure.CAN_FilterNumber=0; //过滤器0
CAN_FilterInitStructure.CAN_FilterMode=CAN_FilterMode_IdList;
CAN_FilterInitStructure.CAN_FilterScale=CAN_FilterScale_32bit; //32位
CAN_FilterInitStructure.CAN_FilterIdHigh=0x0200;////32位ID
CAN_FilterInitStructure.CAN_FilterIdLow=0x0000;
CAN_FilterInitStructure.CAN_FilterMaskIdHigh=0x0200;//32位ID
CAN_FilterInitStructure.CAN_FilterMaskIdLow=0x0000;
CAN_FilterInitStructure.CAN_FilterFIFOAssignment=CAN_Filter_FIFO0;//过滤器0关联到FIFO0
CAN_FilterInitStructure.CAN_FilterActivation=ENABLE; //激活过滤器0
CAN_FilterInit(&CAN_FilterInitStructure);//滤波器初始化
#if CAN_RX0_INT_ENABLE
CAN_ITConfig(CAN1,CAN_IT_FMP0,ENABLE);//FIFO0消息挂号中断允许.
CAN_ClearITPendingBit(CAN1,CAN_IT_FMP0);
NVIC_InitStructure.NVIC_IRQChannel = USB_LP_CAN1_RX0_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; // 主优先级为0
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; // 次优先级为0
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
#endif
return 0;
}
初始化:CAN_Mode_Init(CAN_SJW_1tq,CAN_BS2_8tq,CAN_BS1_7tq,5,CAN_Mode_Normal);//CAN初始化正常模式,波特率450Kbps
中断服务函数:LED3显示CAN接收状态,Rx_Flag为接收到数据标志位
void USB_LP_CAN1_RX0_IRQHandler(void)
{
CanRxMsg RxMessage;
int i=0;
RxMessage.StdId=0x00;
RxMessage.ExtId=0x00;
RxMessage.IDE=0;
RxMessage.DLC=0;
RxMessage.FMI=0;//CAN过滤主控制寄存器
memset( &RxMessage.Data[0],0,8);
LED3 = !LED3;
CAN_Receive(CAN1, 0, &RxMessage);
for(i=0;i<7;i++)
test=RxMessage.Data;
}
printf("test: %s \r\n",test);
CAN_ClearITPendingBit(CAN1,CAN_IT_FMP0);
Rx_Flag=1;
}
另,我板子上没加外部晶振,直接用的内部RC,会不会是这个时钟不准导致波特率对不上引起的?
请各位高手帮忙分析分析,谢谢!~
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