I2C总线及AT24C02读写实验报告

/**************************************************

实验名称：I2C总线实验一

实验目的：利用定时器产生0~99秒表在数码管前两位显示

 每过一秒写入到AT24C02里面，关闭实验板后

 重新打开实验板，秒表从AT24C02读入数据继

 续上一次的计时。

实验备注：

**************************************************/

#include

#define uchar unsigned char

#define uint unsigned int

sbit SDA = P2^0;

sbit SCL = P2^1;

sbit DUAN = P2^6;

sbit WEI = P2^7;

uchar code duan_table[]=

{0x3f,0x06,0x5b,0x4f,

 0x66,0x6d,0x7d,0x07,

 0x7f,0x6f,0x77,0x7c,

 0x39,0x5e,0x79,0x71};

uchar code wei_table[]=

{0xfe,0xfd,0xfb,

 0xf7,0xef,0xdf};

uchar num, sec;

void delay_1us();

void delay_1ms(uchar);

void display(uchar);

void at24_init();

void at24_start();

void at24_stop();

void at24_respons();

void at24_writebyte(uchar);

uchar at24_readbyte(uchar);

void at24_writeadd(uchar,uchar);

uchar at24_readadd(uchar);

void main()

{

at24_init();

sec = at24_readadd(5);

if(sec > 100)

sec = 0;

TMOD = 0x01;

TH0 = (65536-46080)/256;

TL0 = (65536-46080)%256;

EA = 1;

ET0 = 1;

TR0 = 1;

while(1)

{

if(num == 20)

{

num = 0;

sec++;

if(sec == 100)

{

sec = 0;

}

at24_writeadd(5,sec);

}

display(sec);

}

}

void delay_1us()

{

//uchar i, j;

//for(i = 0; i < 1; i++)

//for(j = 0; j < 1; j++);

;;

}

void delay_1ms(uchar x)

{

uchar i, j;

for(i = 0; i < x; i++)

for(j = 0; j < 110; j++);

}

void display(uchar x)

{

DUAN = 1;

P0 = duan_table[x/10];

DUAN = 0;

P0 = 0xff;

WEI = 1;

P0 = wei_table[0];

WEI = 0;

delay_1ms(5);

DUAN = 1;

P0 = duan_table[x%10];

DUAN = 0;

P0 = 0xff;

WEI = 1;

P0 = wei_table[1];

WEI = 0;

delay_1ms(5);

}

void at24_init()

{

SDA = 1;

delay_1us();

SCL = 1;

delay_1us();

}

void at24_start()

{

SDA = 1;

delay_1us();

SCL = 1;

delay_1us();

SDA = 0;

delay_1us();

}

void at24_stop()

{

SDA = 0;      //必须先把SDA拉低

delay_1us();

SCL = 1;

delay_1us();

SDA = 1;

delay_1us();

}

void at24_respons()

{

uchar i;

//i = 0;

SCL = 1;

delay_1us();

while((SDA == 1) && (i<250))

i++;

SCL = 0;

delay_1us();

}

void at24_writebyte(uchar dat)

{

uchar i,temp;

i = 0;

temp = dat;

for(i = 0; i < 8; i++)

{

temp = temp<<1;

SCL = 0;

delay_1us();

SDA = CY;

delay_1us();

SCL = 1;

delay_1us();

}

SCL = 0;

delay_1us();

SDA = 1;

delay_1us();

}

uchar at24_readbyte()

{

uchar i, temp;

//i = 0;

//temp = 0;

SCL = 0;

delay_1us();

SDA = 1;

delay_1us();

for(i = 0; i < 8; i++)

{

SCL = 1;

delay_1us();

temp = ((temp<<1) | SDA);

SCL = 0;

delay_1us();

}

return temp;

}

void at24_writeadd(uchar address,uchar dat)

{

EA = 0;

at24_start();

at24_writebyte(0xa0);

at24_respons();

at24_writebyte(address);

at24_respons();

at24_writebyte(dat);

at24_respons();

at24_stop();

EA = 1;

delay_1ms(5);

}

uchar at24_readadd(uchar address)

{

uchar temp;

at24_start();

at24_writebyte(0xa0);

at24_respons();

at24_writebyte(address);

at24_respons();

at24_start();

at24_writebyte(0xa1);

at24_respons();

temp = at24_readbyte();

at24_stop();

delay_1ms(1);

return temp;

}

void Timer0() interrupt 1

{

TH0 = (65536-46080)/256;

TL0 = (65536-46080)%256;

num++;

}

/**************************************************

实验名称：I2C总线实验二

实验目的：从键盘上读取两位数值，并储存在AT24C02里，

 再从AT24C02中读取出来显示在数码管前两位。

 1,数码管显示00的时候，按下键盘输入要储存

 的两位数字。

 2.数码管显示已经储存的数字，并等待键盘的

 第二次输入。

实验备注：

**************************************************/

#include

#define uchar unsigned char

#define uint unsigned int

sbit SDA = P2^0;

sbit SCL = P2^1;

sbit DUAN = P2^6;

sbit WEI = P2^7;

uchar code duan_table[]=

{0x3f,0x06,0x5b,0x4f,

 0x66,0x6d,0x7d,0x07,

 0x7f,0x6f,0x77,0x7c,

 0x39,0x5e,0x79,0x71};

uchar code wei_table[]=

{0xfe,0xfd,0xfb,

 0xf7,0xef,0xdf};

uchar code heng_table[]=

{0xfe, 0xfd, 0xfb, 0xf7, 0xef, 0xdf};

uchar num_led, num_i2c, flag_key, ge, shi;

void delay_4us();

void delay_1ms(uchar);

void display(uchar);

uchar keyscan();

uchar keynum();

void i2c_init();

void i2c_respons();

void i2c_start();

void i2c_stop();

void i2c_writebyte(uchar);

uchar i2c_readbyte();

void i2c_writeadd(uchar,uchar);

uchar i2c_readadd(uchar);

void main()

{

flag_key = 0;

num_led = 0;

num_i2c = 0;

i2c_init();

i2c_writeadd(3, num_i2c);

while(1)

{

display(num_led);

num_i2c = keynum();

if(flag_key == 3)

{

i2c_writeadd(3, num_i2c);

flag_key = 0;

}

num_led = i2c_readadd(3);

}

}

void delay_4us()

{;;}

void delay_1ms(uchar x)

{

uchar i, j;

for(i = 0; i < x; i++)

for(j = 0; j < 110; j++);

}

void display(uchar num)

{

DUAN = 1;

P0 = duan_table[num/10];

DUAN = 0;

P0 = 0xff;

WEI = 1;

P0 = wei_table[0];

WEI = 0;

delay_1ms(2);

DUAN = 1;

P0 = duan_table[num%10];

DUAN = 0;

P0 = 0xff;

WEI = 1;

P0 = wei_table[1];

WEI = 0;

delay_1ms(2);

}

uchar keyscan()

{

uchar key, temp;

key = 44;

P3 = heng_table[0];

temp = P3;

temp = temp & 0xf0;

if(temp != 0xf0)

{

delay_1ms(5);

temp = P3;

temp = temp & 0xf0;

if(temp != 0xf0)

{

temp = P3;

switch (temp)

{

case 0xee:

key = 1;

break;

case 0xde:

key = 2;

break;

case 0xbe:

key = 3;

break;

case 0x7e:

key = 4;

break;

}

while(temp != 0xf0)

{

temp = P3;

temp = temp & 0xf0;

}

}

}

P3 = heng_table[1];

temp = P3;

temp = temp & 0xf0;

if(temp != 0xf0)

{

delay_1ms(5);

temp = P3;

temp = temp & 0xf0;

if(temp != 0xf0)

{

temp = P3;

switch (temp)

{

case 0xed:

key = 5;

break;

case 0xdd:

key = 6;

break;

case 0xbd:

key = 7;

break;

case 0x7d:

key = 8;

break;

}

while(temp != 0xf0)

{

temp = P3;

temp = temp & 0xf0;

}

}

}

P3 = heng_table[2];

temp = P3;

temp = temp & 0xf0;

if(temp != 0xf0)

{

delay_1ms(5);

temp = P3;

temp = temp & 0xf0;

if(temp != 0xf0)

{

temp = P3;

switch (temp)

{

case 0xeb:

key = 9;

break;

case 0xdb:

key = 0;

break;

case 0xbb:

key = 11;

break;

case 0x7b:

key = 12;

break;

}

while(temp != 0xf0)

{

temp = P3;

temp = temp & 0xf0;

}

}

}

return key;

}

uchar keynum()

{

uchar temp;

temp = 0;

if(flag_key == 0)

{

shi = keyscan();

if(shi != 44)

{

flag_key = 1;

}

}

if(flag_key == 1)

{

ge = keyscan();

if(ge != 44)

{

flag_key = 2;

}

}

if(flag_key == 2)

{

temp = shi*10 + ge;

flag_key = 3;

}

return temp;

}

void i2c_init()

{

SCL = 1;

delay_4us();

SDA = 1;

delay_4us();

}

void i2c_respons()

{

uchar i;

i = 0;

SCL = 1;

delay_4us();

while((SDA ==1) && (i < 250))i++;

SCL = 0;

delay_4us();

}

void i2c_start()

{

SDA = 1;

delay_4us();

SCL = 1;

delay_4us();

SDA = 0;

delay_4us();

}

void i2c_stop()

{

SDA = 0;

delay_4us();

SCL = 1;

delay_4us();

SDA = 1;

delay_4us();

}

void i2c_writebyte(uchar x)

{

uchar i, temp;

temp = x;

for(i = 0; i < 8; i++)

{

temp = temp << 1;

SCL = 0;

     delay_4us();

SDA = CY;

delay_4us();

SCL = 1;

delay_4us();

}

SCL = 0;

delay_4us();

SCL = 1;

delay_4us();

}

uchar i2c_readbyte()

{

uchar i ,temp;

SCL = 0;

delay_4us();

SDA = 1;

delay_4us();

for(i = 0; i < 8; i++)

{

SCL = 1;

delay_4us();

temp = ((temp << 1) | SDA);

SCL = 0;

}

return temp;

}

void i2c_writeadd(uchar address, uchar dat)

{

i2c_start();

i2c_writebyte(0xa0);

i2c_respons();

i2c_writebyte(address);

i2c_respons();

i2c_writebyte(dat);

i2c_respons();

i2c_stop();

}

uchar i2c_readadd(uchar address)

{

uchar temp;

i2c_start();

i2c_writebyte(0xa0);

i2c_respons();

i2c_writebyte(address);

i2c_respons();

i2c_start();

i2c_writebyte(0xa1);

i2c_respons();

temp = i2c_readbyte();

i2c_stop();

return temp;

}

转载于:https://blog.51cto.com/elvinsys/1611127