I2C驱动at24c02问题已解决

发布于 2018-10-22 03:31:34 浏览：5383 订阅该版

想用RTT里面I2C总线驱动24c02

AT24C02线程代码：
```c
static const char * i2c_bus_device_name = "i2c1";
static const rt_uint8_t eeprom_addr = 0x50; /* 1010A2A1A0 - R/W */
struct rt_i2c_bus_device * i2c_device  = RT_NULL;        /* I2C设备句柄 */

void AT24C02_thread_entry(void* parameter)
{  
    rt_uint8_t buffer[2];
        
    rt_uint8_t uart_rx_data;

/* 打开iic */
 if (AT24C02_open(i2c_bus_device_name) != RT_EOK)
 {
 rt_kprintf("i2c1 open error. ");
 }
 
 if(AT24C02_write_reg(0x01, 0x06)!=RT_EOK)//往地址0x01写0x06
 {
// rt_kprintf("write Date1 fail! ");
 }
 if(AT24C02_write_reg(0x02, 0x09)!=RT_EOK)//往地址0x02写0x09
 {
// rt_kprintf("write Date2 fail! ");
 }
 
 while (1)
 {
 if(AT24C02_read_reg(0x01, 1, &buffer[0])!=RT_EOK)
 {
// rt_kprintf("Read Date1 fail! ");
 }
 else
 {
 rt_kprintf("%02X ", buffer[0]);
 rt_kprintf("");
 }
 
 if(AT24C02_read_reg(0x02, 1, &buffer[1])!=RT_EOK)
 {
// rt_kprintf("Read Date1 fail! ");
 }
 else
 {
 rt_kprintf("%02X ", buffer[1]);
 rt_kprintf("");
 }
 
 rt_thread_delay(1000);
 }
}

//返回值: 0,成功 / -1,错误代码
rt_err_t  AT24C02_open(const char *name)
{
    rt_err_t res;

/* 查找系统中的iic设备 */
 i2c_device = rt_i2c_bus_device_find(name); /*查找I2C设备*/
 /* 查找到设备后将其打开 */ 是这里查找设备并未注册i2c1吗？有知道原因的吗？
 if (i2c_device == RT_NULL)
 {
 rt_kprintf("can't find AT24C02 %s device ", i2c_bus_device_name);
 return -RT_ERROR;
 }

rt_kprintf("AT24C02 set i2c bus to %s ", i2c_bus_device_name);

return RT_EOK;
}

//写AT24C02单个寄存器
//reg:寄存器地址
//data:数据
//返回值: 0,正常 / -1,错误代码
rt_err_t AT24C02_write_reg(rt_uint8_t reg, rt_uint8_t data)往地址里写数据这样对吗？
{
    struct rt_i2c_msg msgs;
    rt_uint8_t buf[2] = {reg, data};

msgs.addr  = eeprom_addr;    /* 从机地址 */
    msgs.flags = RT_I2C_WR;       /* 写标志 */
    msgs.buf   = buf;             /* 发送数据指针 */
    msgs.len   = 2;

if (rt_i2c_transfer(i2c_device, &msgs, 1) == 1)
 {
// rt_kprintf("write EEPROM fail! ");
 return RT_EOK;
 }
 else
 {
 return -RT_ERROR;
 }

}

//读取寄存器数据
//reg:要读取的寄存器地址
//len:要读取的数据字节数
//buf:读取到的数据存储区
//返回值: 0,正常 / -1,错误代码
rt_err_t AT24C02_read_reg(rt_uint8_t reg, rt_uint8_t len, rt_uint8_t *buf)从地址里面读取数据这样写对吗？
{
    struct rt_i2c_msg msgs[2];

msgs[0].addr  = eeprom_addr;    /* 从机地址 */
    msgs[0].flags = RT_I2C_WR;       /* 写标志 */
    msgs[0].buf   = ®            /* 从机寄存器地址 */
    msgs[0].len   = 1;               /* 发送数据字节数 */

msgs[1].addr  = eeprom_addr;    /* 从机地址 */
    msgs[1].flags = RT_I2C_RD;       /* 读标志 */
    msgs[1].buf   = buf;             /* 读取数据指针 */
    msgs[1].len   = len;             /* 读取数据字节数 */

if (rt_i2c_transfer(i2c_device, msgs, 2) == 2)
 {
// rt_kprintf("read EEPROM fail! ");
 return RT_EOK;
 }
 else
 {
 return -RT_ERROR;
 }

}
```

有没有高手帮忙看看，谢谢！
![1.png](https://oss-club.rt-thread.org/uploads/201810/22/032424l7655682o57yo85y.png)
![2.png](https://oss-club.rt-thread.org/uploads/201810/22/032405ok1h0212sygn1k0g.png)

18 个回答

还没想好 2018-10-22

这家伙很懒，什么也没写！

fengye 2018-10-22

这家伙很懒，什么也没写！

fengye 2018-10-22

这家伙很懒，什么也没写！

yangjie 认证专家 2018-10-22

hello

fengye 2018-10-22

这家伙很懒，什么也没写！

yangjie 认证专家 2018-10-23

hello

fengye 2018-10-23

这家伙很懒，什么也没写！

yangjie 认证专家 2018-10-23

hello

fengye 2018-10-23

这家伙很懒，什么也没写！

fengye 2018-10-25

这家伙很懒，什么也没写！

>i2c初始化在drv_i2c.c中有的，使用了INIT_DEVICE_EXPORT(drv_i2c_init);进行自动初始化，不需要自己初始化
> ...

---

谢谢，我用的标准库，在i2c.c中修改了相应的端口，目前出现了一个新问题根据I2C设备应用笔记我写了往相应地址写数据函数，第一次调用时数据写不进去，函数如下：

rt_err_t AT24C02_write_reg(rt_uint8_t reg, rt_uint8_t data)
{
    struct rt_i2c_msg msgs;
    rt_uint8_t buf[2] = {reg, data};

msgs.addr  = eeprom_addr;    /* 从机地址 */
    msgs.flags = RT_I2C_WR;       /* 写标志 */
    msgs.buf   = buf;             /* 发送数据指针 */
    msgs.len   = 2;

if (rt_i2c_transfer(i2c_device, &msgs, 1) == 1)
    {
        return RT_EOK;
    }
    else
    {
        rt_kprintf("write EEPROM fail!\r\n");
        return -RT_ERROR;
    }

}

加了延时也不行，能帮我看看吗，线程是这样的：
void AT24C02_thread_entry(void* parameter)
{  
    rt_uint8_t buffer[5];
        
    rt_uint8_t uart_rx_data;

/* 获得i2c 设备句柄*/
    if (AT24C02_open(i2c_bus_device_name) != RT_EOK)
    {
        rt_kprintf("i2c1 open error.\r\n");
        }
                rt_thread_delay(1000);
        
        if(AT24C02_write_reg(0x01, 0x21)!=RT_EOK)//往地址0x01写0x21
        {
                rt_kprintf("write Date1 fail!\r\n");
        }
        rt_thread_delay(10);
        if(AT24C02_write_reg(0x02, 0x22)!=RT_EOK)//往地址0x02写0x22
        {
                rt_kprintf("write Date2 fail!\r\n");
        }
        rt_thread_delay(10);
        if(AT24C02_write_reg(0x03, 0x23)!=RT_EOK)//往地址0x01写0x23
        {
                rt_kprintf("write Date3 fail!\r\n");
        }
        rt_thread_delay(10);        
        if(AT24C02_write_reg(0x04, 0x24)!=RT_EOK)//往地址0x02写0x24
        {
                rt_kprintf("write Date4 fail!\r\n");
        }

rt_thread_delay(10);

while (1)
         {
                if(AT24C02_read_reg(0x01, 1, &buffer[0])!=RT_EOK)
                {
                        rt_kprintf("Read Date1 fail!\r\n");
                }
                else
                {
                        rt_kprintf("%02X ", buffer[0]);
                        rt_kprintf("\r\n ");
                }
                
                if(AT24C02_read_reg(0x02, 1, &buffer[1])!=RT_EOK)
                {
                        rt_kprintf("Read Date2 fail!\r\n");
                }
                else
                {
                        rt_kprintf("%02X ", buffer[1]);
                        rt_kprintf("\r\n ");
                }
                if(AT24C02_read_reg(0x03, 1, &buffer[2])!=RT_EOK)
                {
                        rt_kprintf("Read Date3 fail!\r\n");
                }
                else
                {
                        rt_kprintf("%02X ", buffer[2]);
                        rt_kprintf("\r\n ");
                }
                
                if(AT24C02_read_reg(0x04, 1, &buffer[3])!=RT_EOK)
                {
                        rt_kprintf("Read Date4 fail!\r\n");
                }
                else
                {
                        rt_kprintf("%02X ", buffer[3]);
                        rt_kprintf("\r\n ");
                }
                                
                rt_thread_delay(1000);
         }
}

就第一个数据写出错，后面三个数据都正常，finsh组件打印出来的效果如图：
帮我看看什么情况，谢谢了