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自己花了两天的时间来调试一个时钟芯片:DS3231,刚开始参考高手写的用硬件I2C来操作DS3231较简单
然后自己模仿硬件I2C的工作原理写了一个用模拟I2C来操作的程序,经多次调试之后终于成功.
由于本网站的DS3231程序都不完整,现发布一个完整程序,希望对大家有用.
/**********************************
晶振:11.0592M
模拟I2C总线操作DS3231
2007/11/08
fjh
/**********************************/
#include <iom128v.h>
#include <macros.h>
#include "lcd.c"
#define uchar unsigned char
#define uint unsigned int
#define SCL_H PORTD|=(1<<0)
#define SCL_L PORTD&=~(1<<0)
#define SDA_H PORTD|=(1<<1)
#define SDA_L PORTD&=~(1<<1)
uchar year,month,date,hour,minute,second;
/******************应用程序********************/
void timer1_init(void);
uchar BCD2HEX(uchar val);
uchar B_BCD(uchar val);
void delay(uchar us);
void Start(void);
void Stop(void);
void SendByte(uchar Dat);
uchar ReceiveByte(uchar b);
void I2cByteWrite(uchar device,uint addr,uchar bytedata);
uchar I2cByteRead(uchar device,uint addr);
void get_show_time(void);
/**********************************************/
void port_init(void)
{
PORTA = 0xff;
DDRA = 0xff;
PORTB = 0xff;
DDRB = 0xff;
PORTC = 0xff;
DDRC = 0xff;
PORTD = 0x00;
DDRD = 0xff;
PORTE = 0xff;
DDRE = 0xff;
PORTF = 0xff;
DDRF = 0xff;
PORTG = 0x00;
DDRG = 0x00;
}
// actual value: 1.000Sec (0.0%)
void timer1_init(void)
{
TCCR1B = 0x00; //stop
TCNT1H = 0xD5; //setup
TCNT1L = 0xD1;
OCR1AH = 0x2A;
OCR1AL = 0x2F;
OCR1BH = 0x2A;
OCR1BL = 0x2F;
OCR1CH = 0x2A;
OCR1CL = 0x2F;
ICR1H = 0x2A;
ICR1L = 0x2F;
TCCR1A = 0x00;
TCCR1B = 0x05; //start Timer
TIMSK = 0x04; //timer interrupt sources
}
#pragma interrupt_handler timer1_ovf_isr:15
void timer1_ovf_isr(void)
{
//TIMER1 has overflowed
TCNT1H = 0xD5; //reload counter high value
TCNT1L = 0xD1; //reload counter low value
PORTF=~PORTF;
get_show_time();
}
uchar BCD2HEX(uchar val) //BCD转换为Byte
{
unsigned char i;
i= val&0x0f;
val >>= 4;
val &= 0x0f;
val *= 10;
i += val;
return i;
}
uchar B_BCD(uchar val)//B码转换为BCD码
{
uchar i,j,k;
i=val/10;
j=val%10;
k=j+(i<<4);
return k;
}
void delay(uchar us)
{
while(us--);
}
/************************START***************************/
void Start(void)
{
SDA_H;
delay(5);
SCL_H;
delay(5);
SDA_L;
delay(5);
}
/********************************************************/
/************************STOP****************************/
void Stop(void)
{
SDA_L;
delay(5);
SCL_H;
delay(5);
SDA_H;
delay(5);
}
/********************************************************/
/***********向I2C总线发送一个字节+接收一个ACK************/
void SendByte(uchar Dat)
{
uchar i=0;
uchar T_Data=0;
DDRD|=(1<<1);//输出
SCL_L;
delay(10);
T_Data=Dat;
for(i=0;i<8;i++)
{
if(T_Data&0x80)
SDA_H;
else
SDA_L;
delay(5);
SCL_L;
delay(5);
SCL_H;
delay(5);
T_Data=T_Data<<1;
SCL_L;
delay(5);
}
SDA_H;//释放总线
delay(5);
SCL_L; /*********************/
delay(5);//接收一个ACK,不做处理
SCL_H; /*********************/
delay(5);
SCL_L;
}
/********************************************************/
/**********从I2C总线上读取一个字节+发送一个ACK***********/
uchar ReceiveByte(uchar b)
{
uchar i;
uchar temp;
uchar Dat=0;
/*
SDA_H;
delay(5);
SCL_L;
delay(5);
*/
DDRD&=~(1<<1);//输入
for(i=0;i<8;i++)
{
SCL_H;
delay(5);
Dat=Dat<<1;
delay(5);
temp=PIND;
if(temp&0x02)
Dat|=0x01;
else
Dat|=0x00;
delay(5);
SCL_L;
delay(5);
}
DDRD|=(1<<1);//输出
if(b)//每收一个数后发送ACK或nACK
SDA_H;
else
SDA_L;
delay(5);
SCL_H;
delay(5);
SCL_L;
delay(5);
SDA_H; //释放总线
delay(100);
return Dat;
}
/****************************************************/
/***********将一个字节写入DS3231指定的地址***********/
void I2cByteWrite(uchar device,uint addr,uchar bytedata)
{
Start();
delay(5);
SendByte(device);
delay(5);
SendByte(addr);
delay(5);
SendByte(bytedata);
delay(5);
Stop();
}
/****************************************************/
/************从DS3231指定的地址读一个字节************/
uchar I2cByteRead(uchar device,uint addr)
{
uchar Dat=0;
Start();
SendByte(device);
delay(5);
SendByte(addr);
delay(5);
Start();//Restart
SendByte(0xd1);//读数
delay(5);
Dat=ReceiveByte(1);//只接收一个字节,所以发nACK
Stop();
return Dat;
}
/***************************************************/
/*********************读取时间**********************/
void Readtime(void)
{
year=I2cByteRead(0xd0,0x06); //年
month=I2cByteRead(0xd0,0x05); //月
date=I2cByteRead(0xd0,0x04); //日
hour=I2cByteRead(0xd0,0x02); //时
minute=I2cByteRead(0xd0,0x01);//分
second=I2cByteRead(0xd0,0x00);//秒
}
/***************************************************/
/****************修改时间,BCD码输入*****************/
void ModifyTime(uchar yea,uchar mon,uchar da,uchar hou,uchar min,uchar sec)
{
uchar temp=0;
temp=B_BCD(yea);
I2cByteWrite(0xD0,0x06,temp);//修改年
temp=B_BCD(mon);
I2cByteWrite(0xD0,0x05,temp);//修改月
temp=B_BCD(da);
I2cByteWrite(0xD0,0x04,temp);//修改日
temp=B_BCD(hou);
I2cByteWrite(0xD0,0x02,temp);//修改时
temp=B_BCD(min);
I2cByteWrite(0xD0,0x01,temp);//修改分
temp=B_BCD(sec);
I2cByteWrite(0xD0,0x00,temp);//修改秒
}
/****************************************************/
/****************读取时间 计算 并显示****************/
void get_show_time(void)
{
uchar temp1,temp2,a=0,b=0;
temp1=I2cByteRead(0xd0,0x06); //年
temp2=BCD2HEX(temp1);
a=temp2/10;
b=temp2-a*10;
disp_two_char (0x81,tab[a],tab);
disp_one_word(0x82,"年");
temp1=I2cByteRead(0xd0,0x05); //月
temp2=BCD2HEX(temp1);
a=temp2/10;
b=temp2-a*10;
disp_two_char (0x83,tab[a],tab);
disp_one_word(0x84,"月");
temp1=I2cByteRead(0xd0,0x04); //日
temp2=BCD2HEX(temp1);
a=temp2/10;
b=temp2-a*10;
disp_two_char (0x85,tab[a],tab);
disp_one_word(0x86,"日");
temp1=I2cByteRead(0xd0,0x02); //时 24小时制
temp1&=0x3f;
temp2=BCD2HEX(temp1);
a=temp2/10;
b=temp2-a*10;
disp_two_char (0x91,tab[a],tab);
disp_one_word(0x92,"时");
temp1=I2cByteRead(0xd0,0x01); //分
temp2=BCD2HEX(temp1);
a=temp2/10;
b=temp2-a*10;
disp_two_char (0x93,tab[a],tab);
disp_one_word(0x94,"分");
temp1=I2cByteRead(0xd0,0x00); //秒
temp2=BCD2HEX(temp1);
a=temp2/10;
b=temp2-a*10;
disp_two_char (0x95,tab[a],tab);
disp_one_word(0x96,"秒");
}
/****************************************************/
/*******************MAIN函数*************************/
void main()
{
CLI();
port_init();
init_lcd ();
I2cByteWrite(0xD0,0x0e,0);
I2cByteWrite(0xD0,0x0f,0);
ModifyTime(7,11,20,12,59,00);//初始化时钟,2007/11/20,12/59/00
//小时采用24小时制
timer1_init();
SEI();
lat_disp (0x00,0x00);//显示点阵
while(1)
{
}
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阿莫论坛20周年了!感谢大家的支持与爱护!!
知道什么是神吗?其实神本来也是人,只不过神做了人做不到的事情 所以才成了神。 (头文字D, 杜汶泽)
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