#include <reg52.h>
#include <intrins.h>
#define PCF8591_ADDR 0x90
#define DACOUT_EN 0x40
typedef unsigned char uchar;
typedef unsigned int uint;
uchar code leddata[]={
0x3F, //"0"
0x06, //"1"
0x5B, //"2"
0x4F, //"3"
0x66, //"4"
0x6D, //"5"
0x7D, //"6"
0x07, //"7"
0x7F, //"8"
0x6F, //"9"
0x77, //"A"
0x7C, //"B"
0x39, //"C"
0x5E, //"D"
0x79, //"E"
0x71, //"F"
0x76, //"H"
0x38, //"L"
0x37, //"n"
0x3E, //"u"
0x73, //"P"
0x5C, //"o"
0x40, //"-"
0x00, //熄灭
0x00 //自定义
};
/*位声明*/
sbit SCL = P2^1;
sbit SDA = P2^0;
sbit du = P2^6;
sbit we = P2^7;
sbit AD0_OK = P1^0;
sbit AD1_OK = P1^1;
sbit AD2_OK = P1^2;
sbit AD3_OK = P1^3;
/*延时5us*/
void delay_5us()
{
_nop_();
}
/*延时1ms*/
void delay(uint z)
{
uint x,y;
for(x = z; x > 0; x--)
for(y = 114; y > 0 ; y--);
}
/**数码显示函数（为0的位不显示）**/
void display_567bit(uchar cc)
{
uchar ge,shi,bai;
bai = cc / 100;
shi = (cc - bai*100) / 10;
ge = cc % 10 ;
if(cc > 99 && cc < 999)
{
P0 = 0xff;
we = 1;P0 = 0xdf;//1101 1111
we = 0;
du = 1;P0 = leddata[bai];
du = 0;
delay(1);
P0 = 0xff;//数码管清零
we = 1;P0 = 0xbf;
we = 0;
du = 1;P0 = leddata[shi];
du = 0;
delay(1);
P0 = 0xff;
we = 1;P0 = 0x7f;
we = 0;
du = 1;P0 = leddata[ge];
du = 0;
delay(1);
}
else if(cc > 9 && cc < 99)
{
P0 = 0xff;//数码管清零
we = 1;P0 = 0xbf;
we = 0;
du = 1;P0 = leddata[shi];
du = 0;
delay(1);
P0 = 0xff;
we = 1;P0 = 0x7f;
we = 0;
du = 1;P0 = leddata[ge] + 0x80;
du = 0;
delay(1);
}
else
{
P0 = 0xff;
we = 1;P0 = 0x7f;
we = 0;
du = 1;P0 = leddata[ge] + 0x80;
du = 0;
delay(1);
}
}
/**数码显示函数（为0的位不显示）**/
void display_34bit(uchar cc)
{
uchar ge,shi,bai;
bai = cc / 100;
shi = (cc - bai*100) / 10;
ge = cc % 10 ;
if(cc > 9 && cc < 99)
{
P0 = 0xff;//数码管清零
we = 1;P0 = 0xf7;//1111 0111
we = 0;
du = 1;P0 = leddata[shi];
du = 0;
delay(1);
P0 = 0xff;
we = 1;P0 = 0xef;//1110 1111
we = 0;
du = 1;P0 = leddata[ge] + 0x80;
du = 0;
delay(1);
}
else
{
P0 = 0xff;
we = 1;P0 = 0xef;//1110 1111
we = 0;
du = 1;P0 = leddata[ge] + 0x80;
du = 0;
delay(1);
}
}
/**数码显示函数（为0的位不显示）**/
void display_012bit(uchar cc)
{
uchar ge,shi,bai;
bai = cc / 100;
shi = (cc - bai*100) / 10;
ge = cc % 10 ;
if(cc > 99 && cc < 999)
{
P0 = 0xff;
we = 1;P0 = 0xfe;//1111 1110
we = 0;
du = 1;P0 = leddata[bai];
du = 0;
delay(3);
P0 = 0xff;//数码管清零
we = 1;P0 = 0xfd;//1111 1101
we = 0;
du = 1;P0 = leddata[shi];
du = 0;
delay(3);
P0 = 0xff;
we = 1;P0 = 0xfb;//1111 1011
we = 0;
du = 1;P0 = leddata[ge] + 0x80;
du = 0;
delay(1);
}
else if(cc > 9 && cc < 99)
{
P0 = 0xff;//数码管清零
we = 1;P0 = 0xfd;//1111 1101
we = 0;
du = 1;P0 = leddata[shi];
du = 0;
delay(3);
P0 = 0xff;
we = 1;P0 = 0xfb;//1111 1011
we = 0;
du = 1;P0 = leddata[ge] + 0x80;
du = 0;
delay(3);
}
else
{
P0 = 0xff;
we = 1;P0 = 0xfb;//1111 1011
we = 0;
du = 1;P0 = leddata[ge] + 0x80;
du = 0;
delay(3);
}
}
/*I2C初始化*/
void I2C_init()
{
SCL = 1;
_nop_();
SDA = 1;
_nop_();
}
/*I2C起始信号*/
void I2C_start() //I2C起始信号
{
SDA = 1;
_nop_(); //小延时 让总线稳定
SCL = 1;
delay_5us();
SDA = 0;
delay_5us();
}
/*I2C终止信号*/
void I2C_stop() //I2C终止信号
{
SDA = 0;
_nop_(); //小延时 让总线稳定
SCL = 1;
delay_5us();
SDA = 1;
delay_5us();
}
/*主机发送应答*/
void master_answer(bit i) //主机发送应答信号，以回复从机是否应答
{
SCL = 0; //拉低时钟总线SLC，允许数据总线SDA上的数据变化
_nop_(); //稳定总线
if(i)
{
SDA = 0;//发送应答
}
else
{
SDA =1;//发送非应答
}
_nop_();
SCL = 1; //拉高时钟总线，以让从机读走主机的应答信号
delay_5us(); //按照I2C时序，必须延时4us
//此时从机已经读完应答信号
SCL = 0; //时钟拉低，占用总线继续通信，
_nop_();
SDA = 1; //数据总线拉高，释放数据总线，交由从机控制
_nop_();
}
/*测试从机应答*/
bit test_answer() //测试从机的应答
{
SCL = 1; //只有时钟总线为1 ，才能接受应答信号
delay_5us();//I2C时序要求，必须延时4us
if(SDA)
{
SCL = 0; //拉低，以让SDA可变
_nop_();
I2C_stop();
return(0); //返回非应答
}
else
{
SCL = 0; //拉低，以让SDA可变
_nop_();
return(1); //返回非应答
}
SCL = 0; //时钟拉低，占用总线继续通信，
_nop_();
SDA = 1; //数据总线拉高，释放数据总线，交由从机控制
_nop_();
}
/*发送一个字节*/
void I2C_send_byte(uchar byte)
{
uchar i;
for(i = 0; i < 8 ;i++)
{
SCL = 0;
_nop_();
if(byte & 0x80) //1000 0000
{
SDA = 1;
_nop_();
}
else
{
SDA = 0;
_nop_();
}
SCL = 1;
_nop_();
byte <<= 1; //byte = byte << 1;
}
SCL = 0; //时钟拉低，占用总线继续通信
_nop_();
SDA = 1; //数据总线拉高，释放数据总线
_nop_();
}
/*读一个字节*/
uchar I2C_read_byte()
{
uchar i,dat;
SCL = 0;
_nop_();
SDA = 1;
_nop_();
for(i = 0; i < 8 ;i++)
{
SCL = 1; //SCL置高以使SDA保持，才可以读数据
_nop_();
if(SDA)
{
dat = dat | 0x01;
}
else
{
dat = dat & 0xfe;
}
_nop_();
SCL = 0;
_nop_();
if(i < 7)
{
dat = dat << 1;
}
}
return (dat);
SCL = 0; //时钟拉低，占用总线继续通信
_nop_();
SDA = 1; //数据总线拉高，释放数据总线
_nop_();
}
/*DAC发送数据*/
bit DAC_OUT(uchar dat)
{
bit ACK_flag;
I2C_start();
I2C_send_byte(PCF8591_ADDR + 0);
if(test_answer() == 0)
{
ACK_flag = 1;
}
I2C_send_byte(DACOUT_EN); //DA输出使能
if(test_answer() == 0)
{
ACK_flag = 1;
}
I2C_send_byte(dat);
if(test_answer() == 0)
{
ACK_flag = 1;
}
I2C_stop();
delay(5);
if(ACK_flag == 1)
{
return 0;
}
else
return 1;
}
/*读AD数据*/
uchar ADC_Read(uchar CON)
{
uchar DAC_Value;
bit ACK_flag;
I2C_start();
I2C_send_byte(PCF8591_ADDR + 0);
if(test_answer() == 0)
{
ACK_flag = 1;
}
I2C_send_byte(CON);
if(test_answer() == 0)
{
ACK_flag = 1;
}
master_answer(0);
I2C_start();
I2C_send_byte(PCF8591_ADDR + 1);
if(test_answer() == 0)
{
ACK_flag = 1;
}
DAC_Value = I2C_read_byte(); //将读出的数据赋给 全局变量 DAC_Value
master_answer(0);
I2C_stop();
delay(2);
if(ACK_flag == 1)
{
return 0;
}
else
return DAC_Value;
}
void main()
{
I2C_init();
while(1)
{
if( DAC_OUT(ADC_Read(0x00)) ) AD0_OK = 0; else AD0_OK = 1;
display_012bit(ADC_Read(0x00));
if( DAC_OUT(ADC_Read(0x01)) ) AD1_OK = 0; else AD1_OK = 1;
display_34bit(ADC_Read(0x01));
if( DAC_OUT(ADC_Read(0x02)) ) AD2_OK = 0; else AD2_OK = 1;
display_567bit(ADC_Read(0x02));
if( DAC_OUT(ADC_Read(0x03)) ) AD3_OK = 0; else AD3_OK = 1;
}
}
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