stm32---CAN通信
捕获.PNG
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can.c
#include "can.h"
/*************************************************************
函数名：CAN_Mode_Init(u8 tsjw,u8 tbs2,u8 tbs1,u16 brp,u8 mode)
功能：CAN初始化
变量：
//tsjw:重新同步跳跃时间单元.范围:CAN_SJW_1tq~ CAN_SJW_4tq
//tbs2:时间段2的时间单元. 范围:CAN_BS2_1tq~CAN_BS2_8tq;
//tbs1:时间段1的时间单元. 范围:CAN_BS1_1tq ~CAN_BS1_16tq
//brp :波特率分频器.范围:1~1024; tq=(brp)*tpclk1
//波特率=Fpclk1/((tbs1+tbs2+1)*brp);
//mode:CAN_Mode_Normal,普通模式;CAN_Mode_LoopBack,回环模式;
//Fpclk1的时钟在初始化的时候设置为36M,如果设置CAN_Mode_Init(CAN_SJW_1tq,CAN_BS2_8tq,CAN_BS1_9tq,4,CAN_Mode_LoopBack);
//则波特率为:36M/((8+9+1)*4)=500Kbps
//返回值:0,初始化OK;
// 其他,初始化失败;
**************************************************************/
void CAN_Mode_Init(u8 tsjw,u8 tbs2,u8 tbs1,u16 brp,u8 mode)
{
GPIO_InitTypeDef GPIO_InitStructure;
CAN_InitTypeDef CAN_InitStructure;
CAN_FilterInitTypeDef CAN_FilterStructure;
#if CAN_RX0_INT_ENABLE
NVIC_InitTypeDef NVIC_InitStructure;
#endif
//1*开启CAN时钟和对应引脚时钟
RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN1,ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);
//2*引脚初始化配置
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_11;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU; //上拉输入模式
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA,&GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //复用推挽输出
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA,&GPIO_InitStructure);
//3*CAN初始化配置
CAN_InitStructure.CAN_Prescaler = brp; //分频系数为brp+1
CAN_InitStructure.CAN_Mode=mode; //模式设置
CAN_InitStructure.CAN_BS1=tbs1; //Tbs1范围
CAN_InitStructure.CAN_BS2=tbs2; //Tbs2范围
CAN_InitStructure.CAN_SJW=tsjw; //重新同步跳跃宽度的
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
CAN_InitStructure.CAN_NART=ENABLE; //使用报文自动传输
CAN_InitStructure.CAN_RFLM=DISABLE; //报文不锁定，新的覆盖旧的
CAN_InitStructure.CAN_TTCM=DISABLE; //非时间触发通信模式
CAN_InitStructure.CAN_TXFP=DISABLE;//优先级由报文标识符决定
CAN_Init(CAN1,&CAN_InitStructure);
//4*过滤器初始化配置
CAN_FilterStructure.CAN_FilterNumber =0; //过滤器0
CAN_FilterStructure.CAN_FilterMode=CAN_FilterMode_IdMask; //掩码模式，缺点是有误差，报表模式缺点是可识别ID少
CAN_FilterStructure.CAN_FilterScale=CAN_FilterScale_32bit; //32位
CAN_FilterStructure.CAN_FilterIdHigh=0x0000; //32位ID
CAN_FilterStructure.CAN_FilterIdLow = 0x0000;
CAN_FilterStructure.CAN_FilterMaskIdHigh=0x0000; //32位掩码
CAN_FilterStructure.CAN_FilterMaskIdLow=0x0000;
CAN_FilterStructure.CAN_FilterFIFOAssignment=CAN_FilterFIFO0;//过滤器0关联到FIFO0（邮箱0）
CAN_FilterStructure.CAN_FilterActivation=ENABLE;//激活过滤器0
CAN_FilterInit(&CAN_FilterStructure);//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.
NVIC_InitStructure.NVIC_IRQChannel = USB_LP_CAN1_RX0_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1; // 主优先级为1
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; // 次优先级为0
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
#endif
}
#if CAN_RX0_INT_ENABLE //使能RX0中断
//中断服务函数
void USB_LP_CAN1_RX0_IRQHandler(void)
{
CanRxMsg RxMessage;
int i=0;
CAN_Receive(CAN1, 0, &RxMessage);
for(i=0;i<8;i++)
printf("rxbuf[%d]:%d\r\n",i,RxMessage.Data[i]);
}
#endif
//can发送一组数据(固定格式:ID为0X12,标准帧,数据帧)
//len:数据长度(最大为8)
//msg:数据指针,最大为8个字节.
//返回值:0,成功;
// 其他,失败;
u8 CAN_Send_Msg(u8 *msg,u8 len)
{
u16 i=0;
u8 mbox;
CanTxMsg TxMessage;
TxMessage.StdId=0x12; //标准ID，设置为扩展时自动变0
TxMessage.ExtId=0x12; //扩展ID
TxMessage.IDE=0; //决定是标准(1)还是扩展模式(0)
TxMessage.RTR=0; //表明是数据帧(0)还是遥控帧(1),当是遥控帧时TxMessage.Data为0
TxMessage.DLC=len; //数据长度(最大为8)
for(i=0;i=0xfff) return 1; //失败
return 0; //成功
}
//can口接收数据查询
//buf:数据缓存区;
//返回值:0,无数据被收到;
// 其他,接收的数据长度;
u8 CAN_Receive_Msg(u8 *buf)
{
u32 i;
CanRxMsg RxMessage; //结构体定义
if(CAN_MessagePending(CAN1,CAN_FIFO0)==0) return 0; //邮箱为空
CAN_Receive(CAN1,CAN_FIFO0,&RxMessage);
for(i=0;i can.h
#ifndef _can_H
#define _can_H
#include "system.h"
void CAN_Mode_Init(u8 tsjw,u8 tbs2,u8 tbs1,u16 brp,u8 mode);
u8 CAN_Send_Msg(u8 *msg,u8 len);
u8 CAN_Receive_Msg(u8 *buf);
#endif
main.c
#include "system.h"
#include "SysTick.h"
#include "led.h"
#include "usart.h"
#include "can.h"
#include "key.h"
int main()
{
u8 i,j,key;
u8 mode=0; //默认是正常模式
u8 res;
u8 tbuf[8],char_buf[8];
u8 rbuf[8];
SysTick_Init(72);
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2); //中断优先级分组 分2组
LED_Init();
USART1_Init(9600);
KEY_Init();
CAN_Mode_Init(CAN_SJW_1tq,CAN_BS2_8tq,CAN_BS1_9tq,4,CAN_Mode_Normal);
while(1)
{
key =KEY_Scan(0);
if(key==KEY_UP) //切换模式
{
mode = !mode; //模式切换，正常模式0x00,环回模式0x01
CAN_Mode_Init(CAN_SJW_1tq,CAN_BS2_8tq,CAN_BS1_9tq,4,mode);
if(mode==0)
printf("Normal Mode\r\n");//正常模式
else
printf("LoopBack Mode\r\n");//环回模式
}
else if(key==KEY_DOWN)//发送接收数据
{
for(j=0;j<8;j++)
{
tbuf[j] = j;
char_buf[j] = tbuf[j]+0x30;//加0x30变ASC码
}
res = CAN_Send_Msg(tbuf,8); //返回0成功
if(res)
printf("Send Failed\r\n");
else
printf("发送数据:%s\r\n",char_buf);
}
res = CAN_Receive_Msg(rbuf); //返回0失败，非0为接收数据长度
if(res) //res不为0就可进入
{
for(j=0;j