单片机iic方式驱动1602源程序 PCF8547T芯片 -

#include <intrins.h>
sbit SCL = P3^0;
sbit SDA = P3^1;
bit ack;
/*sbit RS=P2^0;
sbit Rw=P2^1;
sbit E =P2^2; */
sbit deng =P1^0;
unsigned char LCD_data;
unsigned char code digit[ ]={"0123456789"}; //定义字符数组显示数字
/*bt0=date&0x01;
bt1=date&0x02;
bt2=date&0x04;
bt3=date&0x08;
bt4=date&0x10;
bt5=date&0x20;
bt6=date&0x40;
bt7=date&0x80; */
//*****************延时************************
void delay_nus(unsigned int n) //N us延时函数
{
unsigned int i=0;
for (i=0;i<n;i++)
_nop_();
}
void delay_nms(unsigned int n) //N ms延时函数
{
unsigned int i,j;
for (i=0;i<n;i++)
for (j=0;j<1140;j++);
}
void nop4()
{
_nop_(); //等待一个机器周期
_nop_(); //等待一个机器周期
_nop_(); //等待一个机器周期
_nop_(); //等待一个机器周期
}
//***************************************88
void Start()
{
SDA=1;
_nop_();
SCL=1;
nop4();
SDA=0;
nop4();
SCL=0;
_nop_();
_nop_();
}
void Stop()
{
SDA=0;
_nop_();
SCL=0;
nop4();//>4us后SCL跳变
SCL=1;
nop4();
SDA=1;
_nop_();
_nop_();
}
//******************************************
void Write_A_Byte(unsigned char c)
{
unsigned char BitCnt;
for(BitCnt=0;BitCnt<8;BitCnt++) //要传送的数据长度为8位
{
if((c<<BitCnt)&0x80) SDA=1; //判断发送位
else SDA=0;
_nop_();
SCL=1; //置时钟线为高，通知被控器开始接收数据位
nop4();
_nop_();
SCL=0;
}
_nop_();
_nop_();
SDA=1; //8位发送完后释放数据线，准备接收应答位
_nop_();
_nop_();
SCL=1;
_nop_();
_nop_();
_nop_();
if(SDA==1)ack=0;
else ack=1; //判断是否接收到应答信号
SCL=0;
_nop_();
_nop_();
}
bit Write_Random_Address_Byte(unsigned char add,unsigned char dat)
{
Start(); //启动总线
Write_A_Byte(add); //发送器件地址
if(ack==0)return(0);
Write_A_Byte(dat); //发送数据
if(ack==0)return(0);
Stop(); //结束总线
return(1);
}
//********************液晶屏使能*********************
void Enable_LCD_write()
{
LCD_data|=(1<<(3-1));//E=1;
Write_Random_Address_Byte(0x4e,LCD_data);
delay_nus(2);
LCD_data&=~(1<<(3-1));//E=0;
Write_Random_Address_Byte(0x4e,LCD_data);
}
//*************写命令****************************
void LCD_write_command(unsigned char command)
{
delay_nus(16);
LCD_data&=~(1<<(1-1));//RS=0;
LCD_data&=~(1<<(2-1));//RW=0;
Write_Random_Address_Byte(0x4e,LCD_data);
LCD_data&=0x0f; //清高四位
LCD_data|=command & 0xf0; //写高四位
Write_Random_Address_Byte(0x4e,LCD_data);
Enable_LCD_write();
command=command<<4; //低四位移到高四位
LCD_data&=0x0f; //清高四位
LCD_data|=command&0xf0; //写低四位
Write_Random_Address_Byte(0x4e,LCD_data);
Enable_LCD_write();
}
//*************写数据****************************
void LCD_write_data(unsigned char value)
{
delay_nus(16);
LCD_data|=(1<<(1-1));//RS=1;
LCD_data&=~(1<<(2-1));//RW=0;
Write_Random_Address_Byte(0x4e,LCD_data);
LCD_data&=0X0f; //清高四位
LCD_data|=value&0xf0; //写高四位
Write_Random_Address_Byte(0x4e,LCD_data);
Enable_LCD_write();
value=value<<4; //低四位移到高四位
LCD_data&=0x0f; //清高四位
LCD_data|=value&0xf0; //写低四位
Write_Random_Address_Byte(0x4e,LCD_data);
Enable_LCD_write();
}
//**********************设置显示位置*********************************
void set_position(unsigned char x,unsigned char y)
{
unsigned char position;
if (y == 0)
position = 0x80 + x;
else
position = 0xc0 + x;
LCD_write_command(position);
}
//**********************显示字符串*****************************
void display_string(unsigned char x,unsigned char y,unsigned char *s)
{
set_position(y-1,x-1);
while (*s)
{
LCD_write_data(*s);
s++;
}
}
//********************显示数字*******************************xs
void display_num(unsigned char x,unsigned char y,unsigned int num)
{
unsigned char i,j,k,m,n;
set_position(y-1,x-1);
i=num/10000;
j=num/1000%10;
k=num/100%10;
m=num/10%10;
n=num%10;
LCD_write_data(digit[i]); //将万位数字的字符常量写入LCD
LCD_write_data(digit[j]); //将千位数字的字符常量写入LCD
LCD_write_data(digit[k]);
LCD_write_data(digit[m]);
LCD_write_data('.');
LCD_write_data(digit[n]);
}
//*************液晶初始化****************************
void LCD_init(void)
{
LCD_write_command(0x28);
delay_nus(40);
LCD_write_command(0x28);
delay_nus(40);
Enable_LCD_write();
delay_nus(40);
LCD_write_command(0x28); //4位显示！！！！！！！！！！！！！！！！！！
LCD_write_command(0x0c); //显示开
LCD_write_command(0x01); //清屏
delay_nms(2);
}
//
//********************按键*********************
void button()
{
bit button1;
if (deng==0){button1=~button1;}
if(button1==0)
{
LCD_data|=(1<<(4-1));//E=1;
Write_Random_Address_Byte(0x4e,LCD_data);
}
if(button1==1)
{
LCD_data&=~(1<<(4-1));//E=0;
Write_Random_Address_Byte(0x4e,LCD_data);
}
}

复制代码