freqe.c

测量T0管脚出入的方波频率

/******************************************
功能：测量T0管脚出入的方波频率，只限0---250Hz
*******************************************/
#include<reg52.h>

sbit LED_DIG = P1^3;
sbit LED_COM = P1^2;
unsigned char counter = 0;
unsigned char Disbuf[]={0,0,0};
unsigned char code DisCode[] = {0x0C0,0xF9,0xA4,0xB0,0x99,0x92,
								0x82,0xF8,0x80,0x90,0xFF};
								//共阳极数码管码表，定位在ROM中
/********************************
	显示延时
*********************************/
void Delay(void)
{
	unsigned char i = 10;
	while(i--);
}
/********************************
	带参数传递的显示程序
*********************************/
void Display(unsigned char Dat[3])
{
	static unsigned char i = 0;
	unsigned LED_Posit = 0x01;
	for(i = 0;i<3;i++)			//只用3个数码管
	{
		P0 = DisCode[Dat[i]];	//送段选
		LED_DIG = 1;
		LED_DIG = 0;
		P0 = LED_Posit;				//选通一个数码管
		LED_COM = 1;
		LED_COM = 0;
		Delay();
		P0 = 0;				//消隐
		LED_COM = 1;
		LED_COM = 0;
		LED_Posit<<=1;
	}
}/********************************
	主函数
*********************************/
void main()
{
	TMOD = 0x15;
	TH1 = 50000>>8;		//一次定时50ms
	TL1 = 50000;
	TL0 = 0;
	TR0 = TR1 =ET1 = EA = 1;
	while(1)
	{
		Display(Disbuf);
	}
}
/********************************
	T1中断服务子函数
*********************************/
void T1_SR() interrupt 3
{
	TH1 = 50000>>8;		//一次定时50ms
	TL1 = 50000;
	if(counter++==20)	//定时一秒
	{
		counter = 0;
		TR0 = 0;
		Disbuf[2] = TL0/100;
		Disbuf[1] = (TL0%100)/10;
		Disbuf[0] = TL0%10;
		TL0 = 0;
		TR0 = 1;
	}
}