51 PWM脉冲信号发生器 proteus仿真

#include <REGX52.H> #include "Delay.h" #include "Key.h" #include "Nixie.h" #include "Timer0.h" #include "LM1602.h" #define uint unsigned int #define uchar unsigned char sbit BZ=P1^5; //蜂鸣器输出端口 sbit PWM=P2^0; //P2^0口输出PWM sbit key1=P3^0; sbit key2=P3^1; sbit key3=P3^2; sbit key4=P3^3; uint time, upper, floor; //time为中断计数变量，upper为占空比上限，floor为占空比下限， uint count=25,cyc=50,t=100000; //count为占空比初始值，cyc为周期中间变量，注：周期=cyc*10. uchar i=4; /***********延时xms程序***********/ void Delayxms(uint z) { uchar x, y; while(z--) { x = 2; y = 239; do { while (--y); } while (--x); } } /***********定时器0初始化***********/ void T0_init() { TMOD=0x01; //定时器0工作于方式1 TH0=(65536-10)/256; //定时器0初值，每10us产生一次中断 TL0=(65536-10)%256; TR0=1; ET0=1; EA=1; } /***********初始化***********/ void init() { LCD_Init (); LCD_display(count*100/cyc); LCD_display0(100/cyc); } /*********主函数********************/ void main() { T0_init(); init(); while(1) { Delayxms(2); if(key1==0) //占空比上调键按下； { Delayxms(2); //按键消抖 while(key1==0); Delayxms(2); count+=cyc/10; //步进加50/10=10； if(count>90) { count=100; } LCD_display(count*100/cyc); } if(key2==0) //占空比下调键按下； { Delayxms(2); while(key2==0); Delayxms(2); count-=cyc/10; if(count<10) { count=0; } LCD_display(count*100/cyc); } if(key3==0) //周期中间变量上调键按下； { Delayxms(2); while(key3==0); Delayxms(2); cyc+=10; if(cyc>100) cyc=100; LCD_display0(100/cyc); LCD_display(count*100/cyc); } if(key4==0) //周期中间变量下调键按下； { Delayxms(2); while(key4==0); Delayxms(2); cyc-=10; LCD_display0(100/cyc); LCD_display(count*100/cyc); if(cyc<1) cyc=1; } } } /**************定时0中断处理******************/ void timer0_int() interrupt 1 { TR0=0; //设置定时器初值期间，关闭定时器 TH0=(65536-10)/256; //定时器0初值，每10us产生一次中断 TL0=(65536-10)%256; TR0=1; time++; if(time<count) PWM=1; //输出高电平 else if(time>=count && time<cyc) PWM=0; //输出低电平 else time=0; if(count > cyc) count=cyc; }