iar9-5.c

手把手教你学AVR单片机C程序设计实验程序

#include <iom16.h>
#include<intrinsics.h>
#include "lcd1602_8bit.c"
uchar __flash title[]={"PWM test"};
#define uchar unsigned char
#define uint unsigned int
#define xtal 8
#define GET_BIT(x,y) (x&(1<<y))
uchar wide;

void port_init(void)
{
 PORTD = 0x70; 
 DDRD  = 0xF0;
 __no_operation();
 DDRD  = 0x80;
}

void timer2_init(void)
{
 TCCR2 = 0x00; //stop
 ASSR  = 0x00; //set async mode
 TCNT2 = 0x01; //setup
 OCR2  = 0xFF;
 TCCR2 = 0x61; //start
}

//call this routine to initialize all peripherals
void init_devices(void)
{
 
 port_init();
 timer2_init();

 MCUCR = 0x00;
 GICR  = 0x00;
 TIMSK = 0x00; //timer interrupt sources
 
}

void scan_s1(void)
{
if(GET_BIT(PIND,4)==0)
 {
  Delay_nms(10);
  if(GET_BIT(PIND,4)==0)
  {if(wide<255)wide++;
  Delay_nms(200);}
 }
}

void scan_s2(void)
{
if(GET_BIT(PIND,5)==0)
 {
  Delay_nms(10);
  if(GET_BIT(PIND,5)==0)
  {if(wide>0)wide--;
  Delay_nms(200);}
 }
}

void main(void) 
{
uint voltage;
init_devices();
Delay_nms(400);
DDRA=0xff;PORTA=0x00;
DDRB=0xff;PORTB=0x00;
InitLcd();
ePutstr(4,0,title);
DisplayOneChar(1,1,'O'); 
DisplayOneChar(2,1,'C');
DisplayOneChar(3,1,'R');
DisplayOneChar(4,1,'2');
DisplayOneChar(5,1,':');
DisplayOneChar(12,1,'.'); 
DisplayOneChar(15,1,'V');
  while(1) 
  {
  scan_s1();
  scan_s2();  
  DisplayOneChar(6,1,(wide/100)+0x30); 
  DisplayOneChar(7,1,(wide/10)%10+0x30); 
  DisplayOneChar(8,1,(wide%10)+0x30); 
  OCR2=wide;
  voltage=(uint)wide;
  voltage=(voltage*196)/100;
  DisplayOneChar(11,1,(voltage/100)+0x30); 
  DisplayOneChar(13,1,(voltage/10)%10+0x30); 
  DisplayOneChar(14,1,(voltage%10)+0x30); 
  }						
}