/**********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);
 }
}