stm32f103c8t6 硬件iic驱动及at24c02读写

硬件IIC驱动：

1. 定义IIC相关的GPIO引脚；
2. 初始化IIC总线；
3. 发送IIC起始信号；
4. 发送设备地址；
5. 发送数据或读取数据；
6. 发送IIC停止信号。

以下是一个简单的STM32F103C8T6硬件IIC驱动的示例代码：

#include "stm32f10x.h"
#include "i2c.h"

#define I2C_SCL_PIN     GPIO_Pin_6
#define I2C_SDA_PIN     GPIO_Pin_7
#define I2C_GPIO        GPIOB
#define I2C_RCC_GPIO    RCC_APB2Periph_GPIOB

#define I2C_SPEED       100000

void i2c_init(void)
{
    GPIO_InitTypeDef GPIO_InitStructure;
    I2C_InitTypeDef I2C_InitStructure;

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);
    RCC_APB2PeriphClockCmd(I2C_RCC_GPIO, ENABLE);

    GPIO_InitStructure.GPIO_Pin = I2C_SCL_PIN | I2C_SDA_PIN;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD;
    GPIO_Init(I2C_GPIO, &GPIO_InitStructure);

    I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
    I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;
    I2C_InitStructure.I2C_OwnAddress1 = 0;
    I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;
    I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
    I2C_InitStructure.I2C_ClockSpeed = I2C_SPEED;

    I2C_Init(I2C1, &I2C_InitStructure);
    I2C_Cmd(I2C1, ENABLE);
}

void i2c_start(void)
{
    while(I2C_GetFlagStatus(I2C1, I2C_FLAG_BUSY));
    I2C_GenerateSTART(I2C1, ENABLE);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));
}

void i2c_stop(void)
{
    I2C_GenerateSTOP(I2C1, ENABLE);
    while(I2C_GetFlagStatus(I2C1, I2C_FLAG_STOPF));
}

void i2c_send_byte(uint8_t byte)
{
    I2C_SendData(I2C1, byte);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));
}

uint8_t i2c_receive_byte(void)
{
    I2C_AcknowledgeConfig(I2C1, ENABLE);
    while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_RECEIVED));
    uint8_t byte = I2C_ReceiveData(I2C1);
    I2C_AcknowledgeConfig(I2C1, DISABLE);
    return byte;
}

void i2c_send_address(uint8_t address, uint8_t direction)
{
    if(direction == I2C_Direction_Transmitter)
    {
        address = (address << 1);
    }
    else
    {
        address = (address << 1) | 0x01;
    }
    I2C_Send7bitAddress(I2C1, address, direction);
    if(direction == I2C_Direction_Transmitter)
    {
        while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_TRANSMITTER_MODE_SELECTED));
    }
    else
    {
        while(!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_RECEIVER_MODE_SELECTED));
    }
}

void i2c_write_data(uint8_t address, uint8_t* data, uint8_t length)
{
    i2c_start();
    i2c_send_address(address, I2C_Direction_Transmitter);
    for(uint8_t i=0; i<length; i++)
    {
        i2c_send_byte(data[i]);
    }
    i2c_stop();
}

void i2c_read_data(uint8_t address, uint8_t* data, uint8_t length)
{
    i2c_start();
    i2c_send_address(address, I2C_Direction_Receiver);
    for(uint8_t i=0; i<length; i++)
    {
        data[i] = i2c_receive_byte();
    }
    i2c_stop();
}

AT24C02读写：

AT24C02是一个2Kbit的串行EEPROM芯片，使用IIC总线通信。以下是一个简单的AT24C02读写的示例代码：

#include "stm32f10x.h"
#include "i2c.h"

#define AT24C02_ADDRESS     0xA0
#define AT24C02_PAGE_SIZE   8

void at24c02_write_byte(uint16_t address, uint8_t data)
{
    uint8_t buffer[3];
    buffer[0] = address >> 8;
    buffer[1] = address & 0xFF;
    buffer[2] = data;

    i2c_write_data(AT24C02_ADDRESS, buffer, 3);
}

uint8_t at24c02_read_byte(uint16_t address)
{
    uint8_t buffer[2];
    buffer[0] = address >> 8;
    buffer[1] = address & 0xFF;

    i2c_write_data(AT24C02_ADDRESS, buffer, 2);

    uint8_t data;
    i2c_read_data(AT24C02_ADDRESS, &data, 1);

    return data;
}

void at24c02_write_page(uint16_t address, uint8_t* data, uint8_t length)
{
    uint8_t buffer[AT24C02_PAGE_SIZE + 2];
    buffer[0] = address >> 8;
    buffer[1] = address & 0xFF;
    for(uint8_t i=0; i<length; i++)
    {
        buffer[2+i] = data[i];
    }

    i2c_write_data(AT24C02_ADDRESS, buffer, length+2);
}

void at24c02_read_buffer(uint16_t address, uint8_t* data, uint8_t length)
{
    uint8_t buffer[2];
    buffer[0] = address >> 8;
    buffer[1] = address & 0xFF;

    i2c_write_data(AT24C02_ADDRESS, buffer, 2);
    i2c_read_data(AT24C02_ADDRESS, data, length);
}

在使用AT24C02时，需要注意以下几点：

1. 写入单个字节时，地址只需要两个字节；
2. 读取单个字节时，需要先写入地址，然后再读取数据；
3. 写入一页数据时，一页大小为8个字节，地址需要两个字节；
4. 读取多个字节时，需要先写入地址，然后再读取指定长度的数据。