mega16试验板测试代码2-液晶1602四线显示

//delay.h

/**********延时函数*****************/
/*-----------------------------------------------
delay_us :1us延时函数
------------------------------------------------*/
void delay_us(void)
{
asm("nop");
}
/*-----------------------------------------------
delay_nus :长延时函数
输入参数: t :延时时间 us
------------------------------------------------*/
void delay_nus(unsigned int t)
{
while(t--)
delay_us();
}
/*----------------------------------------------
delay_ms :1ms延时函数
-----------------------------------------------*/
void delay_ms(void)
{
unsigned int i;
for(i=0;i<1140;i++);
}
/*----------------------------------------------
delay_nms :长延时函数
输入参数: t :延时时间 ms
-----------------------------------------------*/
void delay_nms(unsigned int t)
{
while(t--)
delay_ms();
}

//lcd1602.h

/*-------------------------------------------
RS----------PC2
RW----------GND
EN----------PC3
D4-D7-------PC4-PC7
---------------------------------------------*/
//定义MCU与LCD的接口
#define LCD_EN_PORT PORTC
#define LCD_EN_DDR DDRC
#define LCD_RS_PORT PORTC
#define LCD_RS_DDR DDRC
#define LCD_DATA_PORT PORTC
#define LCD_DATA_DDR DDRC
#define LCD_DATA_PIN PINC
#define LCD_EN 0x08 //portc3 out
#define LCD_RS 0x04 //portc2 out
#define LCD_DATA 0xf0 //portc4/5/6/7 out

/*----------------------------------------------------------
Public function prototypes
----------------------------------------------------------*/
void LCD_init (void);
void LCD_en_write (void);
void clear(void);
void LCD_write_char(unsigned command,unsigned data);
void LCD_set_xy(unsigned char x, unsigned char y);

/*------------------------------------------------------------
函数: lcd1602口线初始化和液晶初始化
-------------------------------------------------------------*/
void LCD_init(void) //液晶初始化
{
LCD_DATA_DDR|=LCD_DATA;
LCD_EN_DDR|=LCD_EN;
LCD_RS_DDR|=LCD_RS;
delay_nms(15);
LCD_write_char(0x28,0); //4位显示
delay_nms(15);
LCD_write_char(0x0c,0); //显示开
delay_nms(15);
LCD_write_char(0x01,0); //清屏
}

/*------------------------------------------------------------
函数: 设置显示地址
para: x---the display address of a line limit: 0---15
y---the display line limit 0 or 1
--------------------------------------------------------------*/
void LCD_set_xy(unsigned char x, unsigned char y) //写地址函数
{
unsigned char address;
if(y ==0)
address=0x80+x; //the first line
else
address=0xc0+x; //the second line
LCD_write_char(address,0);
}
/*-------------------------------------------------------------
函数: lcd1602使能
*--------------------------------------------------------------*/
void LCD_en_write(void) //液晶使能
{
LCD_EN_PORT|=LCD_EN;
delay_nus(5);
LCD_EN_PORT&=~LCD_EN;
}
/*------------------------------------------------------------
函数: 写命令或数据到lcd1602
参数：command: 0---写数据, 1---写命令
data: 所要写的命令或数据
*-------------------------------------------------------------*/
void LCD_write_char(unsigned command,unsigned data)
{
unsigned command_temp,data_temp;
command_temp=command;
data_temp=data;
delay_nus(25);
if(command==0)
{
LCD_RS_PORT|=LCD_RS; //RS=1
LCD_DATA_PORT&=0X0f;
LCD_DATA_PORT|=data_temp&0xf0; //写高四位
LCD_en_write();
data_temp=data_temp<<4;
LCD_DATA_PORT&=0X0f;
LCD_DATA_PORT|=data_temp&0xf0; //写低四位
LCD_en_write();
}
else
{
LCD_RS_PORT&=~LCD_RS; //RS=0
LCD_DATA_PORT&=0X0f;
LCD_DATA_PORT|=command_temp&0xf0; //写高四位
LCD_en_write();
command_temp=command_temp<<4;
LCD_DATA_PORT&=0x0f;
LCD_DATA_PORT|=command_temp&0xf0; //写低四位
LCD_en_write();
}
}
/*-------------------------------------------------------------
函数: 清屏lcd1602
---------------------------------------------------------------*/
void clear(void)
{
unsigned char i;
LCD_set_xy(0,0);
for(i=0;i<16;i++)
LCD_write_char(0,' ');
LCD_set_xy(0,1);
for(i=0;i<16;i++)
LCD_write_char(0,' ');
}
/*-------------------------------------------------------------
函数: 写字符串
参数：列---X=0~15,行---Y=0~1 写地址
s为所要写的字符串
---------------------------------------------------------------*/
void LCD_write_string(unsigned char X,unsigned char Y,unsigned char *s)
{
LCD_set_xy(X,Y);
while(*s)
{
LCD_write_char(0,*s);
s++;
}
}

/*-------------------------------------------------------------
函数: 写数字
参数：列---X=0~15,行---Y=0~1 写地址
dat为所要写的数字
---------------------------------------------------------------*/
void LCD_write_data(unsigned char X,unsigned char Y,int dat)
{
unsigned char fuhao;
unsigned char data[5];
unsigned char i;

if(dat<0)
{
fuhao='-';
dat=0-dat;
}
else
fuhao=' ';
data[0]=fuhao;
data[1]=dat/1000+0x30; dat%=1000;
data[2]=dat/100+0x30; dat%=100;
data[3]=dat/10+0x30;
data[4]=dat%10+0x30;

LCD_set_xy(X,Y);
for(i=0;i<5;i++)
LCD_write_char(0,data[i]);
}

//test.c

//ICC-AVR application builder : 2008-11-4 9:30:11
// Target : M16
// Crystal: 7.3728Mhz

#include
#include

#include "delay.h"
#include "lcd1602.h"

unsigned char string1[]={"LCD1602 DIS TEST"};
unsigned char string2[]={" Number:"};

void main(void)
{
LCD_init();
clear();
delay_nms(10);
LCD_write_string(0,0,string1);
LCD_write_string(0,1,string2);
while(1)
{
LCD_write_data(10,1,-1234);
}
}