frequencymeter.c

使用3310液晶的数字频率计（AVR）.

#include <iom8v.h>
#include <macros.h>
#include "lcd.h"
#include "bmp.h"

unsigned long counter;
unsigned char countlow;
unsigned char fre[]="00.000000";
unsigned char time[]="00:00:00";

#pragma interrupt_handler timer2_ovf_isr:iv_TIMER2_OVF
void timer2_ovf_isr(void)
  {
    unsigned char i;
    //TCCR2=0;
    
    PORTB &= ~0X02;                   //关闭闸门  
    
    //读取计数值
    counter = TCNT1;                  //读取T/C1计数值（频率值的高16位）
    counter = counter*256;            //计算频率值的高16位
    countlow = (PIND & 0b11000000)|(PINC & 0b00111111);
                                      //读取计数值的低8位
    counter = counter + countlow;     //计算频率值
    
    PORTD |= 0X01;                     //74LS393清零
    TCNT1  = 0; 
    
    PORTD &= ~0X01;                     //关闭清零
    TCNT2 = 0X80;                       //定时时间1秒
    
    PORTB |= 0X02;                     //打开闸门
    
    //实时时钟显示
    time[7]++;                         
    
    fre[0]=counter  /10000000+0x30;
    counter=counter %10000000;
    fre[1]=counter  /1000000+0x30;
    counter=counter %1000000;
    fre[3]=counter  /100000+0x30;
    counter=counter %100000;
    fre[4]=counter  /10000+0x30;
    counter=counter %10000;
    fre[5]=counter  /1000+0x30;
    counter=counter %1000;
    fre[6]=counter  /100+0x30;
    counter=counter %100;
    fre[7]=counter  /10 + 0x30;
    fre[8]=counter  %10 + 0x30;
    
    LCD_write_String(0,2,fre);
    LCD_draw_map(14,2,Bmp003,7,14);                  //显示小数点
    LCD_draw_map(62,2,MHz,22,14);                    //显示频率单位
    
    if ( time[7] > (9+0x30) ) 
      {  
      	time[6] ++;
      	time[7] -= 10;
      }
    if ( time[6] > (5+0x30) )
      {
      	time[4] ++;
      	time[6] -= 6;
      }
    if (time[4]> (9+0x30))
      {
      	time[3]++;
      	time[4]-=10;
      }
    if (time[3] > (5+0x30))
      {
      	time[1]++;
      	time[3]-=6;
      }
    if (time[1]>(9+0x30))
      {
      	time[0]++;
      	time[1]-=10;
      }
    LCD_write_String(2,4,time);
    LCD_draw_map(16,4,Bmp002,7,14);           //显示“：”字符
    LCD_draw_map(37,4,Bmp002,7,14);
    
  }

/******************************************************************************/
void main(void) 
  {
    unsigned char i;
    OSCCAL=0xA3;                              // 8M系统内部时钟校准
    
    //设置MCU的I/O口
    DDRB |= LCD_RST | LCD_DC | LCD_CE | SPI_MOSI | SPI_CLK ;
    
    DDRB |= 0x02;                             //计数闸门
    DDRD |= 0X01;                             //74LS393清零
    //DDRD |= 0X08;                             //LED
    //DDRD &= ~0X20;   
    DDRC &= 0B11000000;                         
    DDRD &= 0B00111111;
    
    SPSR |= BIT(SPI2X);                        // 设置SPI时钟倍速
    SPCR |= BIT(SPE)|BIT(MSTR);		       // 使能SPI接口，主机模式，4M时钟
 
    LCD_init();
    //LCD_clear();	                       // 清屏
    LCD_draw_map(12,0,Bmp001,60,13);
    
    ASSR  = 1 <<AS2;                           //选择异步时钟
    TCNT2 = 0X80;                              //定时时间1秒
    TCCR2 = (1<<CS22)|(1<<CS21);               //T/C2预分频比256
    TIMSK |= BIT(TOIE2);                       //允许TC2溢出中断
     
    TCCR1B |= BIT(CS12)|BIT(CS11)|BIT(CS10);   //时钟外部T1输入，上升源驱动
    
    SEI();
    
    while(1)  
      {
        
      }
  }