51单片机产生pwm波控制舵机
pwm波形状是怎样的,是一个脚上不断输出方波(高电平持续一段固定时间再输出低电平,静态),还是高电平时间在不断变化,到达某一指定时间又归零(动态),帮我看下这个程序,为啥mg995舵机不动。
#include "reg52.h"
#define uchar unsigned char
#define uint unsigned int
sbit pwm=P2^1;
uchar count=0;
void time()
{
TMOD|=0X10;
TH1 = 0xFc;
TL1 = 0x18;
ET1=1;
EA=1;
TR1=1;
}
void Time1() interrupt 3
{
TH1 = 0xFc;
TL1 = 0x18;
count++;
}
void main(){
while(1){
pwm=1;
time();
if(count>=1)
pwm=0;
if(count==19)
{count=0;}
}