stm32can通信

STM32是一款常用的微控制器，它支持CAN总线通信。在使用CAN通信时，需要配置CAN控制器和CAN过滤器，然后才能进行数据的发送和接收。以下是一个简单的CAN通信示例代码：

#include "stm32f4xx.h"

void CAN_Config(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    CAN_InitTypeDef CAN_InitStructure;
    CAN_FilterInitTypeDef CAN_FilterInitStructure;

    // 使能CAN1和GPIOB时钟
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN1, ENABLE);
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);

    // 配置PB8和PB9为复用功能
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
    GPIO_Init(GPIOB, &GPIO_InitStructure);

    // 将PB8和PB9连接到CAN1的RX和TX引脚
    GPIO_PinAFConfig(GPIOB, GPIO_PinSource8, GPIO_AF_CAN1);
    GPIO_PinAFConfig(GPIOB, GPIO_PinSource9, GPIO_AF_CAN1);

    // 配置CAN1
    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_InitStructure.CAN_SJW = CAN_SJW_1tq;
    CAN_InitStructure.CAN_BS1 = CAN_BS1_6tq;
    CAN_InitStructure.CAN_BS2 = CAN_BS2_8tq;
    CAN_InitStructure.CAN_Prescaler = 4;
    CAN_Init(CAN1, &CAN_InitStructure);

    // 配置CAN过滤器
    CAN_FilterInitStructure.CAN_FilterNumber = 0;
    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 = 0;
    CAN_FilterInitStructure.CAN_FilterActivation = ENABLE;
    CAN_FilterInit(&CAN_FilterInitStructure);
}

void CAN_SendData(uint8_t* data, uint8_t len)
{
    CanTxMsg TxMessage;

    // 填充CAN消息结构体
    TxMessage.StdId = 0x123;
    TxMessage.ExtId = 0x00;
    TxMessage.RTR = CAN_RTR_DATA;
    TxMessage.IDE = CAN_ID_STD;
    TxMessage.DLC = len;
    for (int i = 0; i < len; i++) {
        TxMessage.Data[i] = data[i];
    }

    // 发送CAN消息
    while (CAN_Transmit(CAN1, &TxMessage) == CAN_TxStatus_NoMailBox);
}

void CAN_ReceiveData(uint8_t* data, uint8_t* len)
{
    CanRxMsg RxMessage;

    // 接收CAN消息
    if (CAN_MessagePending(CAN1, CAN_FIFO0) > 0) {
        CAN_Receive(CAN1, CAN_FIFO0, &RxMessage);

        // 将数据拷贝到缓冲区
        *len = RxMessage.DLC;
        for (int i = 0; i < *len; i++) {
            data[i] = RxMessage.Data[i];
        }
    }
}

int main(void)
{
    uint8_t tx_data[] = {0x01, 0x02, 0x03};
    uint8_t rx_data[8];
    uint8_t rx_len;

    CAN_Config();

    while (1) {
        CAN_SendData(tx_data, sizeof(tx_data));
        CAN_ReceiveData(rx_data, &rx_len);
    }
}

在上述代码中，CAN_Config函数用于配置CAN控制器和CAN过滤器，CAN_SendData函数用于发送CAN数据帧，CAN_ReceiveData函数用于接收CAN数据帧。