用STM32C8T6通过can总线实现四个电机的驱动，编写出代码，并解释代码

以下是一个简单的基于STM32C8T6的CAN总线控制四个电机的代码示例：

#include "stm32f10x.h"
#include "stm32f10x_can.h"

#define CAN_RX_PIN GPIO_Pin_8
#define CAN_TX_PIN GPIO_Pin_9

#define CAN_REMAP_PORT GPIO_PortB
#define CAN_REMAP_PIN GPIO_PinSource8

#define CAN_SPEED 500000

CAN_InitTypeDef can_init;
CAN_FilterInitTypeDef can_filter_init;
CanTxMsg can_tx_msg;
CanRxMsg can_rx_msg;

void CAN_Configuration(void)
{
    GPIO_InitTypeDef gpio_init;
    CAN_DeInit(CAN1);
    RCC_APB1PeriphClockCmd(RCC_APB1Periph_CAN1, ENABLE);
    RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO | RCC_APB2Periph_GPIOB, ENABLE);

    gpio_init.GPIO_Pin = CAN_RX_PIN;
    gpio_init.GPIO_Mode = GPIO_Mode_IPD;
    GPIO_Init(GPIOB, &gpio_init);

    gpio_init.GPIO_Pin = CAN_TX_PIN;
    gpio_init.GPIO_Speed = GPIO_Speed_50MHz;
    gpio_init.GPIO_Mode = GPIO_Mode_AF_PP;
    GPIO_Init(GPIOB, &gpio_init);

    GPIO_PinRemapConfig(GPIO_Remap1_CAN1, ENABLE);

    can_init.CAN_TTCM = DISABLE;
    can_init.CAN_ABOM = DISABLE;
    can_init.CAN_AWUM = DISABLE;
    can_init.CAN_NART = ENABLE;
    can_init.CAN_RFLM = DISABLE;
    can_init.CAN_TXFP = ENABLE;
    can_init.CAN_Mode = CAN_Mode_Normal;
    can_init.CAN_SJW = CAN_SJW_1tq;
    can_init.CAN_BS1 = CAN_BS1_4tq;
    can_init.CAN_BS2 = CAN_BS2_3tq;
    can_init.CAN_Prescaler = 4;
    CAN_Init(CAN1, &can_init);

    can_filter_init.CAN_FilterNumber = 0;
    can_filter_init.CAN_FilterMode = CAN_FilterMode_IdMask;
    can_filter_init.CAN_FilterScale = CAN_FilterScale_32bit;
    can_filter_init.CAN_FilterIdHigh = 0x0000;
    can_filter_init.CAN_FilterIdLow = 0x0000;
    can_filter_init.CAN_FilterMaskIdHigh = 0x0000;
    can_filter_init.CAN_FilterMaskIdLow = 0x0000;
    can_filter_init.CAN_FilterFIFOAssignment = CAN_Filter_FIFO0;
    can_filter_init.CAN_FilterActivation = ENABLE;
    CAN_FilterInit(&can_filter_init);

    CAN_ITConfig(CAN1, CAN_IT_FMP0, ENABLE);
}

void CAN_Send(uint16_t id, uint8_t* data, uint8_t len)
{
    uint8_t i;

    can_tx_msg.StdId = id;
    can_tx_msg.RTR = CAN_RTR_DATA;
    can_tx_msg.IDE = CAN_ID_STD;
    can_tx_msg.DLC = len;

    for (i = 0; i < len; i++)
    {
        can_tx_msg.Data[i] = data[i];
    }

    CAN_Transmit(CAN1, &can_tx_msg);
}

void CAN_RxMsgHandler(void)
{
    uint8_t i;

    if (CAN_GetITStatus(CAN1, CAN_IT_FMP0) != RESET)
    {
        CAN_Receive(CAN1, CAN_FIFO0, &can_rx_msg);

        if (can_rx_msg.StdId == 0x01 && can_rx_msg.DLC == 4)
        {
            uint8_t speed[4];
            for (i = 0; i < 4; i++)
            {
                speed[i] = can_rx_msg.Data[i];
            }
            // 在这里处理接收到的电机速度
        }

        CAN_ClearITPendingBit(CAN1, CAN_IT_FMP0);
    }
}

int main(void)
{
    CAN_Configuration();

    while (1)
    {
        uint8_t speed[4] = { 0x10, 0x20, 0x30, 0x40 };
        CAN_Send(0x101, speed, 4);
        // 在这里发送电机速度给CAN总线
    }
}

这个代码示例中，我们使用了STM32C8T6的CAN1总线来控制四个电机。在CAN_Configuration函数中，我们首先初始化了CAN总线的GPIO、CAN_InitTypeDef和CAN_FilterInitTypeDef，然后启用CAN总线的时钟。我们还使用了GPIO_PinRemapConfig函数将CAN_RX_PIN和CAN_TX_PIN对应到了PB8和PB9上。

在CAN_Send函数中，我们发送了一个标准ID为0x101的CAN消息，其数据为一个长度为4的数组，表示四个电机的速度。在CAN_RxMsgHandler函数中，我们处理了接收到的CAN消息，如果其标准ID为0x01，数据长度为4，则说明它是电机速度的消息，我们可以从数据中提取出四个电机的速度值进行处理。

在主循环中，我们不断地向CAN总线发送电机速度数据。如果有其他设备向我们发送电机速度的数据，CAN_RxMsgHandler函数将会被调用。