gd32单片机模拟iic程序

以下是基于GD32单片机的模拟IIC程序示例：

#include "gd32f10x.h"

#define SDA_PIN GPIO_PIN_7
#define SDA_GPIO_PORT GPIOB
#define SCL_PIN GPIO_PIN_6
#define SCL_GPIO_PORT GPIOB

#define IIC_SCL_H()   GPIO_BOP(SCL_GPIO_PORT) = SCL_PIN
#define IIC_SCL_L()   GPIO_BC(SCL_GPIO_PORT) = SCL_PIN
#define IIC_SDA_H()   GPIO_BOP(SDA_GPIO_PORT) = SDA_PIN
#define IIC_SDA_L()   GPIO_BC(SDA_GPIO_PORT) = SDA_PIN
#define IIC_SDA_READ()  GPIO_INPUT_PORT_READ(SDA_GPIO_PORT) & SDA_PIN

/* IIC延迟函数 */
void IIC_Delay(void)
{
    uint16_t i = 1000;
    while(i--);
}

/* IIC初始化函数 */
void IIC_Init(void)
{
    gpio_init(SDA_GPIO_PORT, GPIO_MODE_OUT_OD, GPIO_OSPEED_50MHZ, SDA_PIN);
    gpio_init(SCL_GPIO_PORT, GPIO_MODE_OUT_OD, GPIO_OSPEED_50MHZ, SCL_PIN);

    IIC_SCL_H();
    IIC_SDA_H();
}

/* IIC起始信号 */
void IIC_Start(void)
{
    IIC_SDA_H();
    IIC_SCL_H();
    IIC_Delay();
    IIC_SDA_L();
    IIC_Delay();
    IIC_SCL_L();
}

/* IIC停止信号 */
void IIC_Stop(void)
{
    IIC_SDA_L();
    IIC_SCL_H();
    IIC_Delay();
    IIC_SDA_H();
    IIC_Delay();
}

/* IIC等待应答信号 */
uint8_t IIC_Wait_Ack(void)
{
    uint8_t ucErrTime = 0;
    IIC_SDA_H();
    IIC_Delay();
    IIC_SCL_H();
    IIC_Delay();
    while(IIC_SDA_READ())
    {
        ucErrTime++;
        if(ucErrTime > 250)
        {
            IIC_Stop();
            return 1;
        }
    }
    IIC_SCL_L();
    return 0;
}

/* IIC应答信号 */
void IIC_Ack(void)
{
    IIC_SCL_L();
    IIC_SDA_L();
    IIC_Delay();
    IIC_SCL_H();
    IIC_Delay();
    IIC_SCL_L();
}

/* IIC非应答信号 */
void IIC_NAck(void)
{
    IIC_SCL_L();
    IIC_SDA_H();
    IIC_Delay();
    IIC_SCL_H();
    IIC_Delay();
    IIC_SCL_L();
}

/* IIC发送一个字节 */
void IIC_Send_Byte(uint8_t txd)
{
    uint8_t t;
    IIC_SCL_L();
    for(t = 0; t < 8; t++)
    {
        if((txd & 0x80) >> 7)
            IIC_SDA_H();
        else
            IIC_SDA_L();
        txd <<= 1;
        IIC_SCL_H();
        IIC_Delay();
        IIC_SCL_L();
        IIC_Delay();
    }
}

/* IIC读取一个字节 */
uint8_t IIC_Read_Byte(unsigned char ack)
{
    uint8_t i, receive = 0;
    IIC_SDA_H();
    for(i = 0; i < 8; i++)
    {
        IIC_SCL_L();
        IIC_Delay();
        IIC_SCL_H();
        receive <<= 1;
        if(IIC_SDA_READ())
            receive++;
        IIC_Delay();
    }
    if(!ack)
        IIC_NAck();
    else
        IIC_Ack();
    return receive;
}

/* IIC写数据 */
uint8_t IIC_Write(uint8_t addr, uint8_t reg, uint8_t data)
{
    IIC_Start();
    IIC_Send_Byte(addr << 1);
    if(IIC_Wait_Ack()) {
        return 1;
    }
    IIC_Send_Byte(reg);
    if(IIC_Wait_Ack()) {
        return 1;
    }
    IIC_Send_Byte(data);
    if(IIC_Wait_Ack()) {
        return 1;
    }
    IIC_Stop();
    return 0;
}

/* IIC读数据 */
uint8_t IIC_Read(uint8_t addr, uint8_t reg, uint8_t *buf, uint8_t len)
{
    IIC_Start();
    IIC_Send_Byte(addr << 1);
    if(IIC_Wait_Ack()) {
        return 1;
    }
    IIC_Send_Byte(reg);
    if(IIC_Wait_Ack()) {
        return 1;
    }
    IIC_Start();
    IIC_Send_Byte((addr << 1) | 0x01);
    if(IIC_Wait_Ack()) {
        return 1;
    }
    while(len) {
        if(len == 1) {
            *buf = IIC_Read_Byte(0);
        } else {
            *buf = IIC_Read_Byte(1);
        }
        buf++;
        len--;
    }
    IIC_Stop();
    return 0;
}

/* 测试IIC读写 */
int main(void)
{
    uint8_t buf[2] = {0};
    IIC_Init();
    IIC_Write(0xA0, 0x00, 0x01);
    IIC_Read(0xA0, 0x00, buf, 2);
    return 0;
}

在上述代码中，通过定义SDA和SCL的GPIO端口和引脚，实现了IIC总线的模拟。其中，IIC_Start、IIC_Stop、IIC_Wait_Ack、IIC_Ack、IIC_NAck、IIC_Send_Byte、IIC_Read_Byte、IIC_Write和IIC_Read分别对应IIC通信的起始信号、停止信号、等待应答信号、应答信号、非应答信号、发送一个字节、读取一个字节、写数据和读数据等操作。在主函数中，通过调用IIC_Write和IIC_Read函数测试IIC的读写操作。