stm32iic读写eeprom

### STM32 I2C EEPROM 读写 示例代码 教程

#### 初始化I2C外设

为了实现STM32通过I2C接口与EEPROM通信，首先需要初始化I2C外设。这一步骤通常在`i2c.c`文件中完成。

// i2c.c 文件中的部分代码片段
void I2C_Init(void){
    GPIO_InitTypeDef GPIO_InitStruct = {0};
    I2C_InitTypeDef I2C_InitStruct = {0};

    __HAL_RCC_GPIOB_CLK_ENABLE();
    __HAL_RCC_I2C1_CLK_ENABLE();

    /**I2C1 GPIO Configuration    
    PB6     ------> I2C1_SCL
    PB7     ------> I2C1_SDA 
    */
    GPIO_InitStruct.Pin = GPIO_PIN_6 | GPIO_PIN_7;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_OD;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

    I2C_InitStruct.Timing = 0x20909CEC;
    I2C_InitStruct.OwnAddress1 = 0;
    I2C_InitStruct.AddressingMode = I2C_ADDRESSINGMODE_7BIT;
    I2C_InitStruct.DualAddressMode = I2C_DUALADDRESS_DISABLE;
    I2C_InitStruct.OwnAddress2 = 0;
    I2C_InitStruct.GeneralCallMode = I2C_GENERALCALL_DISABLE;
    I2C_InitStruct.NoStretchMode = I2C_NOSTRETCH_DISABLE;

    HAL_I2C_Init(&hi2c1);
}

这段代码展示了如何设置SCL和SDA引脚以及配置I2C参数[^1]。

#### 定义头文件

接着，在`i2c.h`文件里定义必要的宏定义、结构体声明和其他函数原型：

#ifndef __I2C_H__
#define __I2C_H__

#include "stm32f1xx_hal.h"

extern I2C_HandleTypeDef hi2c1;

void I2C_Init(void);
uint8_t I2C_EEPROM_ReadByte(uint16_t DevAddress,uint16_t MemAddress);
void I2C_EEPROM_WriteByte(uint16_t DevAddress,uint16_t MemAddress,uint8_t Data);

#endif /* __I2C_H__ */

这里包含了对外部变量`hi2c1`的声明，并提供了两个用于操作EEPROM的方法——读取字节(`ReadByte`)和写入字节(`WriteByte`)。

#### 主程序逻辑

最后，在`main.c`文件内编写主循环来测试上述功能:

int main(void)
{
    HAL_Init();
    SystemClock_Config(); // 配置系统时钟
    
    I2C_Init();          // 初始化I2C外设

    while (1)
    {
        uint8_t data_to_write = 'H';
        uint8_t read_data;

        // 向指定地址写入单个字节的数据
        I2C_EEPROM_WriteByte(DEVICE_ADDR, MEMORY_ADDR, data_to_write); 

        // 延迟一段时间等待写入完成
        HAL_Delay(WRITE_DELAY_MS);

        // 从相同位置读回该字节并显示其值
        read_data = I2C_EEPROM_ReadByte(DEVICE_ADDR, MEMORY_ADDR);
        
        if(read_data != data_to_write){
            Error_Handler(__FILE__, __LINE__);
        }
    }
}

/**
 * @brief Write a byte to the specified address of an EEPROM device.
 *
 * @param DevAddress The slave address of the target EEPROM device on the bus.
 * @param MemAddress Internal memory address within the EEPROM where writing starts from.
 * @param Data Byte value that will be written into the EEPROM cell at given location.
 */
void I2C_EEPROM_WriteByte(uint16_t DevAddress,uint16_t MemAddress,uint8_t Data){
    HAL_StatusTypeDef status;

    status = HAL_I2C_Mem_Write(&hi2c1, DevAddress, MemAddress, I2C_MEMADD_SIZE_8BIT, &Data, sizeof(Data), WRITE_TIMEOUT);
    if(status != HAL_OK){
        Error_Handler(__FILE__,__LINE__);
    }
}

/**
 * @brief Read one byte from specific address inside an EEPROM chip connected via I2C interface.
 *
 * @param DevAddress Targeted EEPROM's hardware address over I2C communication line.
 * @param MemAddress Location offset inside selected EEPROM which user wants to access.
 * @return Value stored in requested position as single-byte integer type.
 */
uint8_t I2C_EEPROM_ReadByte(uint16_t DevAddress,uint16_t MemAddress){
    uint8_t buffer[1];
    HAL_StatusTypeDef status;

    status = HAL_I2C_Mem_Read(&hi2c1, DevAddress, MemAddress, I2C_MEMADD_SIZE_8BIT, buffer, sizeof(buffer), READ_TIMEOUT);
    if(status != HAL_OK){
        Error_Handler(__FILE__,__LINE__);
    }

    return buffer[0];
}

此段代码实现了向特定内存地址写入字符'H'的操作，并随后尝试从中读取相同的数值以验证成功与否。如果两者不符，则调用错误处理函数报告异常情况。