PIC16F917 Voltmeter

 /*************PIC16F917 MCU program******************************/
/************************************************************************/
/*****File Function : AD acquisition, LCD display program *****/
/*****Program Author : ZhengWen(ClimberWin) *****/
/*****MCU : PIC16F917 internal crystal oscillator *****/
/*****Compile Date : 2010/08/18 *****/
/*****Edition Info : V1.0 *****/
/*********************************************************************/
//Measure AD and display it through LCD
//Pin definition: PORTD=8LED, KEY=RB0(INT) RA5(AN4) as AD input
/*Modification Date: */

/************************************/
#include
#include "english_6x8_pixel.h"
#define uchar unsigned char
#define uint unsigned int
void Init(void);     //初始化子程序
void LCD_init(void); //LCD初始化程序
void LCD_clear(void);
void LCD_write_char(unsigned char c);
void LCD_set_XY(unsigned char X, unsigned char Y);
void LCD_write_english_string(unsigned char X,unsigned char Y,const char *s);
void LCD_write_byte(unsigned char data, unsigned char command);
void delayms(unsigned int count);
void  interrupt  ADint(void);

#define KEY       RB0
#define SPI_CLK                RD0  
#define SPI_MOSI               RD1 
#define LCD_DC                 RD2 
#define LCD_CE                 RD3
#define LCD_RST                RD4 
/***********************************************/

const unsigned char mask_table[8]={0x80,0x40,0x20,0x10,0x08,0x04,0x02,0x01};
float ad_data;//AD数据存储地址
 uchar temp1,temp2;
uint temp3;
/*********************************************/  
void delayms(unsigned int count)
{
 uint i,j;
 for(i=0;i  for(j=0;j<120;j++);
}
/*********************************************/  
void Init(void)
 {
     PORTA = 0B00000000;
     PORTB = 0B00000000;
     PORTD = 0B00000000;    

     TRISA = 0B00100010; //Set RA5 (AN4) RA1 as input
     TRISB = 0B00100001; //Set RB0 as input, as a key port
     TRISD = 0B00000000; //Set PORTD as output, as LCD/LED display port
     RD5=1; //Turn off LED
     RD6=1;
     RD7=1;

///////////AD configuration////////////////////////////////////////
     ANSEL= 0B00010000; //Select AN4 as AD input (PDF 148)
     ADCON0=0B10010001; //AD result format Right justified, select reference voltage VDD-VSS, AN4 input, turn off AD conversion
     ADCON1=0B01010000; //AD conversion clock selection

     ADIE=1;//AD interrupt enable
     PEIE=1;
     ADIF=0;//clear interrupt flag
     GIE=1; //enable general interrupt
/////////////////////////////////////
     LCD_init(); //initialize LCD 
}

void interrupt ADint(void)
  { 
    
    temp1=ADRESL;
    temp2=ADRESH;
    temp3=temp2*256+temp1; //Dx value
    ad_data=(temp3*33000)/1024; //voltage value
    ADIF=0; //clear interrupt flag
    
  }

void LCD_init(void)
  {
    LCD_RST=0; //LCD reset
    NOP();
    LCD_RST=1;
    
    LCD_CE=0 ; //Disable LCD
    NOP();
    LCD_CE=1; //Enable LCD
    NOP();

    LCD_write_byte(0x21, 0); // Use extended commands to set LCD mode
    LCD_write_byte(0xc8, 0); // Set bias voltage
    LCD_write_byte(0x06, 0); // Temperature correction
    LCD_write_byte(0x13, 0); // 1:48
    LCD_write_byte(0x20, 0); // Use basic commands
    LCD_clear(); // Clear the screen
    LCD_write_byte(0x0c, 0); // Set display mode, normal display
        
    LCD_CE=0 ; // Turn off LCD
  }

/////////LCD清屏程序/////////////
void LCD_clear(void)
{
    uint i;
    LCD_write_byte(0x0c, 0);   
    LCD_write_byte(0x80, 0);   
    for (i=0; i<504; i++)
    LCD_write_byte(0x00, 1);//清零  
}

///////////设置LCD坐标///////////////////
void LCD_set_XY(unsigned char X, unsigned char Y)
{
    LCD_write_byte(0x40 | Y, 0);   
    LCD_write_byte(0x80 | X, 0);      
}

/////////////////Character display program/////////////////////
void LCD_write_char(unsigned char c)
{
    uint line;
    c=c-32;
    for (line=0; line<6; line++)
    LCD_write_byte( font6x8[c][line], 1);
}

/////////////////打印字符串/////////////////////////
void LCD_write_english_string(unsigned char X,unsigned char Y, const unsigned char *s)
  {
    uchar i = 0;
    LCD_set_XY(X,Y);
    while(*s) {LCD_write_char(*s++);} 
  }

////////////Write data to LCD//////////////////////
void LCD_write_byte(unsigned char data, unsigned char command)
{
uchar i;
    LCD_CE=0 ; // Enable LCD
    
    if (command == 0)
      {LCD_DC=0 ;} // Send commandelse
    {
      LCD_DC=1 ;} // Send datafor
 
(i=0;i<8;i++)
{
if(data&mask_table[i])
{SPI_MOSI=1;}
else
{SPI_MOSI=0;}
SPI_CLK=0;
NOP();
SPI_CLK=1;
}

    LCD_CE=1; // Turn off LCD
}

/////////////Main program///////////////////////////
void main (void)
{

 Init();//初始化程序 
 LCD_clear();   //LCD清屏
 delayms(1000);
 LCD_write_english_string(0,0,"   AD Test   " ); 
 LCD_write_english_string(0,1,"AD4 Vref=3.3V" ); 

 ADCON0=ADCON0|0B00000010;//开始AD转换
     LCD_set_XY(0,3);
    LCD_write_char('D');
    LCD_write_char('x');
    LCD_write_char(' ');
    LCD_write_char('=');

 
 LCD_set_XY(0,5);
    LCD_write_char('V');
    LCD_write_char('i');
    LCD_write_char('n');
    LCD_write_char('='); 
 LCD_set_XY(72,5);
    LCD_write_char('V');
  while(1)
  {
  LCD_set_XY(30,3);
  LCD_write_char((temp3/1000)+16+32);
 LCD_write_char( (temp3%1000)/100+16+32);
 LCD_write_char( ((temp3%1000)%100)/10+16+32);
 LCD_write_char( ((temp3%1000)%100)%10+16+32);

//ad_data=ad_data*10000;
temp3=(uint)ad_data;
LCD_set_XY(30,5);
 LCD_write_char((temp3/10000)+16+32);
LCD_write_char('.');
 LCD_write_char( (temp3%10000)/1000+16+32);
 LCD_write_char( ((temp3%10000)%1000)/100+16+32);
LCD_write_char( (((temp3%10000)%1000)%100)/10+16+32);
LCD_write_char( (((temp3%10000)%1000)%100)%10+16+32);

delayms(100);
 ADCON0=ADCON0|0B00000010; //Start AD conversion
 
  }
 

}