EEPROM

I2C 驱动AT24C64

发布于 2021-05-10 11:13:48 浏览：1453 订阅该版

7 个回答

flashman2002 2021-05-10

这家伙很懒，什么也没写！

Acuity 2021-05-10

这家伙很懒，什么也没写！

邹成伟 2021-05-11

这家伙很懒，什么也没写！

尝试修改了

msh />
msh />at24cxx_eeprom_sample
EEPROM write data is: a,b,c,d,e,f,g,h 
EEPROM read data is:

代码如下，不知哪里出了问题。

/** at24cxx设备结构体 */
struct at24cxx_device
{
    struct rt_device         parent;
    struct rt_i2c_bus_device *bus;
};

/** at24cxx设备用户操作配置结构体 */
struct at24cxx_config
{
    rt_uint32_t     size;    //设备的总容量
    rt_uint16_t      addr;    //设备地址
    rt_uint16_t        flags;    //I2C操作标志
};

static rt_size_t at24cxx_read(rt_device_t dev, rt_off_t pos, void *buffer, rt_size_t size)
{
    struct at24cxx_device *at24cxx;
    const struct at24cxx_config *cfg;
    struct rt_i2c_msg msg[2];
    rt_uint8_t mem_addr[2] = {0,};
    rt_size_t ret = 0;
    RT_ASSERT(dev != 0);

at24cxx = (struct at24cxx_device *) dev;

RT_ASSERT(at24cxx->parent.user_data != 0);
    cfg = (const struct at24cxx_config *) at24cxx->parent.user_data;

if(pos >= cfg->size)        //寻址地址超标
    {
         return 0;
    }

if(pos + size > cfg->size)    // size超标
    {
         size = cfg->size - pos;
    }
    
    msg[0].addr     = cfg->addr;
    msg[0].flags    = cfg->flags | RT_I2C_WR;
    if(cfg->size < 257)    // at24c01 at24c02, 一页8字节，寻址地址8位
    {
        mem_addr[0] = (rt_uint8_t) pos;
        msg[0].buf     = (rt_uint8_t *) mem_addr;
        msg[0].len     =  1;
    }
    else    // at24c04/08/16 一页16字节，寻址地址9/10/11位
    {
        mem_addr[0]    = (pos >> 8);
        mem_addr[1]    = (rt_uint8_t) pos;
        msg[0].buf    = (rt_uint8_t *) mem_addr;
        msg[0].len     =  2;
    }
    
    msg[1].addr     = cfg->addr;
    msg[1].flags    = cfg->flags | RT_I2C_RD;
    msg[1].buf      = (rt_uint8_t *) buffer;
    msg[1].len      = size;

ret = rt_i2c_transfer(at24cxx->bus, msg, 2);
    return (ret == 2) ? size : 0;

}

static rt_size_t at24cxx_write(rt_device_t dev, rt_off_t pos, const void *buffer, rt_size_t size)
{
    struct at24cxx_device *at24cxx;
    const struct at24cxx_config *cfg;
    struct rt_i2c_msg msg[2];
    rt_uint8_t mem_addr[2] = {0,};
    rt_size_t ret = 0;
    RT_ASSERT(dev != 0);

at24cxx = (struct at24cxx_device *) dev;

RT_ASSERT(at24cxx->parent.user_data != 0);
    cfg = (const struct at24cxx_config *) at24cxx->parent.user_data;

if(pos > cfg->size)
    {
         return 0;
    }

if(pos + size > cfg->size)
    {
         size = cfg->size - pos;
    }
    
    
    // 写入寻址地址
    msg[0].addr     = cfg->addr;
    msg[0].flags    = cfg->flags | RT_I2C_WR;
    if(cfg->size < 257)    // at24c01 at24c02, 一页8字节，寻址地址8位
    {
        mem_addr[0] = (rt_uint8_t) pos;
        msg[0].buf     = (rt_uint8_t *) mem_addr;
        msg[0].len     =  1;
    }
    else    // at24c04/08/16 一页16字节，寻址地址9/10/11位
    {
        mem_addr[0]    = (pos >> 8);
        mem_addr[1]    = (rt_uint8_t) pos;
        msg[0].buf    = (rt_uint8_t *) mem_addr;
        msg[0].len     =  2;
    }
    
    // 使用RT_I2C_NO_START，直接写入buffer数据
    msg[1].addr     = cfg->addr;
    msg[1].flags    = cfg->flags | RT_I2C_WR | RT_I2C_NO_START;
    msg[1].buf      = (rt_uint8_t *) buffer;
    msg[1].len      = size;
    
    ret = rt_i2c_transfer(at24cxx->bus, msg, 2);
    return (ret == 2) ? size : 0;
}

/* RT-Thread device interface */
static rt_err_t at24cxx_init(rt_device_t dev)
{
    return RT_EOK;
}

static rt_err_t at24cxx_open(rt_device_t dev, rt_uint16_t oflag)
{
    return RT_EOK;
}

static rt_err_t at24cxx_close(rt_device_t dev)
{
    return RT_EOK;
}

static rt_err_t at24cxx_control(rt_device_t dev, int cmd, void *args)
{
    return RT_EOK;
}

#ifdef RT_USING_DEVICE_OPS
/** at24cxx设备操作ops */
const static struct rt_device_ops at24cxx_ops =
{
    at24cxx_init,
    at24cxx_open,
    at24cxx_close,
    at24cxx_read,
    at24cxx_write,
    at24cxx_control
};
#endif

/**
* @brief at24cxx设备注册
* @param[in]  *fm_device_name     设备名称
* @param[in]  *i2c_bus            i2c总线设备名称
* @param[in]  *user_data        用户数据 at24cxx_config 
* @return  函数执行结果
* - RT_EOK    执行成功
* - Others     失败
*/
rt_err_t at24cxx_register(const char *fm_device_name, const char *i2c_bus, void *user_data)
{
    static struct at24cxx_device at24cxx_drv;
    struct rt_i2c_bus_device *bus;

bus = rt_i2c_bus_device_find(i2c_bus);
    if (bus == RT_NULL)
    {
        return RT_ENOSYS;
    }

at24cxx_drv.bus = bus;
    at24cxx_drv.parent.type      = RT_Device_Class_Block;
#ifdef RT_USING_DEVICE_OPS
    at24cxx_drv.parent.ops       = &at24cxx_ops;
#else
    at24cxx_drv.parent.init      = at24cxx_init;
    at24cxx_drv.parent.open      = at24cxx_open;
    at24cxx_drv.parent.close     = at24cxx_close;
    at24cxx_drv.parent.read      = at24cxx_read;
    at24cxx_drv.parent.write     = at24cxx_write;
    at24cxx_drv.parent.control   = at24cxx_control;
#endif

at24cxx_drv.parent.user_data = user_data;

return rt_device_register(&at24cxx_drv.parent, fm_device_name, RT_DEVICE_FLAG_RDWR);
}

static struct at24cxx_config at24c64_config = 
{
    .size = 8192,    // 容量，单位字节
    .addr = 0x50,    // 注意该地址为没有移位之前的地址不是0xA0
    .flags = 0,
};

static int at24cxx_eeprom_sample(void)
{
	  rt_err_t ret;
    rt_uint8_t read_buf[8]={0};
	  rt_uint8_t write_buf[8] = {'a','b','c','d','e','f','g','h'};
		
		ret = at24cxx_register("at24c64", "i2c1", &at24c64_config);
		
		//寻找设备
		rt_device_t at24c64_dev = rt_device_find("at24c64");
    if (at24c64_dev == RT_NULL)
    {
        rt_kprintf("at24c64 sample run failed! can't find %s device!\n", "at24c64");        
    }
    rt_device_open(at24c64_dev, RT_DEVICE_FLAG_RDWR);

if(4 == rt_device_write(at24c64_dev, 0, write_buf, 4))
	  {
				rt_kprintf("EEPROM write data is: %c,%c,%c,%c,%c,%c,%c,%c \r\n",write_buf[0],write_buf[1],write_buf[2],write_buf[3],write_buf[4],write_buf[5],write_buf[6],write_buf[7]);
	  }
	  else
	  {
				rt_kprintf("EEPROM write data faild! \n");
	  }
	  if(4 == rt_device_read(at24c64_dev, 0, read_buf, 4))//0x08地址读数据
	  {
				rt_kprintf("EEPROM read data is: %c,%c,%c,%c,%c,%c,%c,%c \r\n",read_buf[0],read_buf[1],read_buf[2],read_buf[3],read_buf[4],read_buf[5],read_buf[6],read_buf[7]);
	  }
	  else
	  {
				rt_kprintf("EEPROM read data faild! \n");
	  }
		 return 0;
}