2020年03月02日 | 【菜鸟入门】stm32 之 eeprom

/* at24c02.c */

#include

#include "init.h"

#include "iic.h"

#define send_slave_addr(a) iic_send_byte(a)

#define send_rom_addr(a) iic_send_byte(a)

#define ROM_SIZE (2*1024) //2K

#define ADDR_SIZE 256

#define PAGE_SIZE 8

#define PAGE 32

int at24c02_init(unsigned char slave_addr)

{

iic_init();

iic_start();

send_slave_addr(slave_addr|IIC_WRITE);

if(iic_recv_ack())

return 0;

else

return 1;

}

int set_rom_addr(unsigned addr)

{

send_rom_addr(addr);

if(iic_recv_ack())

return 0;

else

return 1;

}

int at24c02_write_unpage( unsigned char slave_addr,

unsigned char start_addr,

char buff[],

unsigned char size)

{

delay_ms(1);

if(0 == at24c02_init(slave_addr))

return -1;

if(0 == set_rom_addr(start_addr))

return -1;

if(size > iic_send_str(buff,size))

{

iic_stop();

return 0;

}

  else 

{

iic_stop();

return 1;

}

}

int at24c02_write_page(unsigned char slave_addr,

unsigned char start_addr,

char buff[])

{

delay_ms(1);

if(0 == at24c02_init(slave_addr))

return -1;

if(0 == set_rom_addr(start_addr))

return -1;

if(8 > iic_send_str(buff,8))

{

iic_stop();

return 0;

}

  else 

{

iic_stop();

return 1;

}

}

int at24c02_write(unsigned char slave_addr,

unsigned char start_addr,

char buff[],

unsigned char size)

{

unsigned char addr = 0;

unsigned char send_byte;

unsigned char i;

char temp;

addr = 8 + ((unsigned char)(start_addr/8))*8;//Get Next Page Frist Address

send_byte = addr - start_addr;

if(size <= send_byte)

{

if(-1 == at24c02_write_unpage(slave_addr,start_addr,buff,size))

return -1;

else

return 0;

}

else

{

if(-1 == at24c02_write_unpage(slave_addr,start_addr,buff,send_byte))

return -1;

}

size -= send_byte;

buff += send_byte;

delay_ms(5);

temp = (char)(size/8);

for(i=0; i {

start_addr = addr;

if(-1 == at24c02_write_page(slave_addr,start_addr,buff))

return -1;

addr += 8;

size -= 8;

buff += 8;

delay_ms(5);

}

start_addr = addr;

if(-1 == at24c02_write_unpage(slave_addr,start_addr,buff,size))

return -1;

return 0;

}

int at24c02_read( unsigned char slave_addr,

unsigned char start_addr,

char buff[],

unsigned char size)

{

delay_ms(1);

if(0 == at24c02_init(slave_addr))

return -1;

if(0 == set_rom_addr(start_addr))

return -1;

iic_start();

send_slave_addr(slave_addr|IIC_READ);

if(iic_recv_ack())

return -1;

iic_recv_str(buff,size);

iic_stop();

return size;

}

应用例子：

int main()

{

char str[512];

int length = 0;

sys_init(9);

rs232_init(CPU_72M,9600);

rs232_send_byte('n');

if(-1 == at24c02_write(SLAVE_ADDR,6,__NOTE,strlen(__NOTE)))

rs232_send_str("Write AT24C02 Fail!n",20);

delay_ms(1000);

if(-1 == (length = at24c02_read(SLAVE_ADDR,0,str,64)))

rs232_send_str("Read  AT24C02 Fail!n",20);

rs232_send_str("Read:",strlen("Read:"));

rs232_send_str(str,strlen(str));

return 0;

}