ATmega16输入捕获功能测方波频率
软件平台：AVR Stadio4硬件平台：ATmega16最小系统
程序功能：用输入捕获功能计算方波频率
存在问题：输出频率有时对有时不对
想请教大家程序哪里有问题？
#include <avr/io.h>
#define F_CPU 8000000UL
#include <util/delay.h>
#include <avr/interrupt.h>
#include "LCD1602.h"
#define uint unsigned int
#define uchar unsigned char
uint Rising_Edge,Falling_Edge;
volatile uchar i=0;
uint count; //the number of Overflow
uint Freq;
uchar F_Num;
void Convert_Num(uint Num)
{
F_Num=Num/10000+0x30;
F_Num=Num%10000/1000+0x30;
F_Num=Num%1000/100+0x30;
F_Num=Num%100/10+0x30;
F_Num=Num%10+0x30;
F_Num='\0';
}
int main(void)
{
LCD_Init();
DDRD&=0x00;
PORTD|=0xFF;
TCCR1A=0x00; //all normal mode
TCNT1=0x0000;
TIMSK=0x24; //input capture interrupt enable,and overflow enable
TIFR=(1<<ICF1);
TCCR1B=0x44; //input capture enable rising_edge,Freq:F(I/O)/256,
sei();
LCD_Display(1,1,"Freq:");
while(i<2)
{;}
TCCR1B&=0xF8;
TCNT1=0x0000;
Convert_Num(Rising_Edge);
LCD_Display(1,6,F_Num);
Convert_Num(Falling_Edge);
LCD_Display(1,12,F_Num);
Convert_Num(count);
LCD_Display(2,1,F_Num);
Freq=(uint)(31250.0/((float)(Falling_Edge)+((float)(count)*65536.0)-(float)(Rising_Edge))); //the cycle of the waveform
Convert_Num(Freq);
LCD_Display(2,7,F_Num);
}
ISR(TIMER1_CAPT_vect)
{
if(i==0)
Rising_Edge=ICR1;
else if(i==1)
Falling_Edge=ICR1;
else ;
i++;
}
ISR(TIMER1_OVF_vect)
{
count++;
} 回复【楼主位】chenccl
-----------------------------------------------------------------------
另外：在程序中加入输入捕获的滤波后，程序就不能正常运行了，似乎是停留在While死循环那里 程序调试通过了，出错原因是：信号的幅值不够，应到3v左右。
页:
[1]