STM32的HAL库软件模拟IIC

softiic.h

#ifndef __SOFTI2C_H_
#define __SOFTI2C_H_

#include "main.h"
//使用IICX   PD6,PC1

#define SDA_IN()  {GPIOC->MODER &= ~(3 << 1 * 2);GPIOC->MODER = (0 << 1 * 2);}
#define SDA_OUT() {GPIOC->MODER &= ~(3 << 1 * 2);GPIOC->MODER = (1 << 1 * 2);}

//IO操作函数     
#define i2c_scl_low()    HAL_GPIO_WritePin(GPIOD, GPIO_PIN_6, GPIO_PIN_RESET)
#define i2c_scl_high()   HAL_GPIO_WritePin(GPIOD, GPIO_PIN_6, GPIO_PIN_SET)

#define i2c_sda_low()    HAL_GPIO_WritePin(GPIOC, GPIO_PIN_1, GPIO_PIN_RESET)
#define i2c_sda_high()   HAL_GPIO_WritePin(GPIOC, GPIO_PIN_1, GPIO_PIN_SET)

#define i2c_read_sda()   HAL_GPIO_ReadPin(GPIOC, GPIO_PIN_1)

extern uint32_t delay1us;

void delay_1us(uint32_t delay_1us);

void analog_i2c_delay(void);

void bsp_analog_i2c_init(void);

void bsp_analog_i2c_start(void);

void bsp_analog_i2c_stop(void);

uint8_t bsp_analog_i2c_wait_ack(void);

void bsp_analog_i2c_ack(void);

void bsp_analog_i2c_nack(void);

void bsp_analog_i2c_send_byte(uint8_t data);

uint8_t bsp_analog_i2c_read_byte(void);

#endif

soft.c

#include "softi2c.h"

uint32_t delay1us;

/** 
 * @brief: 1us延时
 * @param {uint32_t} delay_1us
 * @return {*}
 */
void delay_1us(uint32_t delay_1us)
{
    HAL_TIM_Base_Start_IT(&htim3);
    delay1us = delay_1us;
    while (delay1us);
    HAL_TIM_Base_Stop_IT(&htim3);
}

/** 
 * @brief: IIC延时时间
 * @return {*}
 */
void analog_i2c_delay(void)
{
    delay_1us(2);
}

/** 
 * @brief: 软件模拟I2C初始化
 * @return {*}
 */
void bsp_analog_i2c_init(void)
{
    GPIO_InitTypeDef GPIO_InitStruct = {0};

    __HAL_RCC_GPIOD_CLK_ENABLE();
    __HAL_RCC_GPIOC_CLK_ENABLE();

    /*Configure GPIO pins : PD6 */
    GPIO_InitStruct.Pin = GPIO_PIN_6;
    GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    HAL_GPIO_Init(GPIOD, &GPIO_InitStruct);
    
    /*Configure GPIO pins : PC1 */
    GPIO_InitStruct.Pin = GPIO_PIN_1;
    GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);

    bsp_analog_i2c_stop();
}

/** 
 * @brief: I2C 开始,SCL为高电平的时候SDA产生一个下降沿信号
 * @return {*}
 */
void bsp_analog_i2c_start(void)
{
    /*    _____
     *SDA      \_____________
     *    __________
     *SCL           \________
     */
    i2c_sda_high();
    i2c_scl_high();
    analog_i2c_delay();
    i2c_sda_low();
    analog_i2c_delay();
    i2c_scl_low();
    analog_i2c_delay();
}

/** 
 * @brief: I2C 停止,SCL为高电平的时候SDA产生一个上升沿信号
 * @return {*}
 */
void bsp_analog_i2c_stop(void)
{
    /*               _______
     *SDA __________/
     *          ____________
     *SCL _____/
     */
    i2c_sda_low();
    i2c_scl_high();
    analog_i2c_delay();
    i2c_sda_high();
    analog_i2c_delay();
}

/** 
 * @brief: I2C 等待响应
 * @return {*}
 */
uint8_t bsp_analog_i2c_wait_ack(void)
{
    uint32_t timeout = 0;

    i2c_sda_high();
    SDA_IN();
    analog_i2c_delay();
    i2c_scl_high();
    analog_i2c_delay();
    while(i2c_read_sda())
    {
        timeout++;
        if(timeout > 2000)
        {
            return 1;
        }
    }
    i2c_scl_low();
    analog_i2c_delay();
    return 0;
}

/** 
 * @brief: I2C 响应
 * @return {*}
 */
void bsp_analog_i2c_ack(void)
{
    /*           ____
     *SCL ______/    \______
     *    ____         _____
     *SDA     \_______/
     */
    i2c_sda_low();
    analog_i2c_delay();
    i2c_scl_high();
    analog_i2c_delay();
    i2c_scl_low();
    analog_i2c_delay();
    i2c_sda_high();
}

/** 
 * @brief: I2C 不响应
 * @return {*}
 */
void bsp_analog_i2c_nack(void)
{
    /*           ____
     *SCL ______/    \______
     *    __________________
     *SDA
     */
    i2c_sda_high();
    analog_i2c_delay();
    i2c_scl_high();
    analog_i2c_delay();
    i2c_scl_low();
    analog_i2c_delay();
}

/** 
 * @brief: I2C 发送一个字节数据
 * @param {uint8_t} data
 * @return {*}
 */
void bsp_analog_i2c_send_byte(uint8_t data)
{
    uint8_t i;

    SDA_OUT();
    for(i = 0; i < 8; i++)
    {
        if(data & 0x80)
        {
           i2c_sda_high();
        }
        else
        {
            i2c_sda_low();
        }

        analog_i2c_delay();
        i2c_scl_high();
        analog_i2c_delay();
        i2c_scl_low();
        if(i == 7)
        {
            i2c_sda_high();
        }
        data <<= 1;
        analog_i2c_delay();
    }
}

/** 
 * @brief: I2C 读一个字节数据
 * @return {*}
 */
uint8_t bsp_analog_i2c_read_byte(void)
{
    uint8_t i, data = 0;

    i2c_sda_high();
    SDA_IN();
    for(i = 0; i < 8; i++ )
    {
        data <<= 1;
        i2c_scl_high();
        analog_i2c_delay();
        if(i2c_read_sda())
        {
            data++;
        }
        i2c_scl_low();
        analog_i2c_delay();
    }

    return data;
}

部分改写，原处：https://blog.csdn.net/weixin_43808708/article/details/126961103