|
|
- #include "reg52.h"
- unsigned char count; //0.5ms次數(shù)標(biāo)識
- sbit pwm =P0^1 ; //PWM信號輸出
- sbit jia =P3^2; //角度增加按鍵檢測IO口
- sbit jan =P3^3; //角度減少按鍵檢測IO口
- unsigned char jd; //角度標(biāo)識
- void delay(unsigned char i)//延時
- {
- unsigned char j,k;
- for(j=i;j>0;j--)
- for(k=125;k>0;k--);
- }
- void Time0_Init() //定時器初始化
- {
- TMOD = 0x01; //定時器0工作在方式1
- IE = 0x82;
- TH0 = 0xff;
- TL0 = 0xa3; //11.0592MZ晶振，0.1ms
- TR0=1; //定時器開始
- }
- void Time0_Int() interrupt 1 //中斷程序
- {
- TH0 = 0xff; //重新賦值
- TL0 = 0xa3;
- if(count< jd) //判斷0.1ms次數(shù)是否小于角度標(biāo)識
- pwm=1; //確實小于，PWM輸出高電平
- else
- pwm=0; //大于則輸出低電平
- count=(count+1); //0.1ms次數(shù)加1
- count=count%40; //次數(shù)始終保持為40 即保持周期為20ms
- }
- void keyscan() //按鍵掃描
- {
- if(jia==0) //角度增加按鍵是否按下
- {
- delay(10); //按下延時，消抖
- if(jia==0) //確實按下
- {
- jd++; //角度標(biāo)識加1
- count=0; //按鍵按下 則20ms周期從新開始
- if(jd==26)
- jd=25; //已經(jīng)是180度，則保持
- while(jia==0); //等待按鍵放開
- }
- }
- if(jan==0) //角度減小按鍵是否按下
- {
- delay(10);
- if(jan==0)
- {
- jd--; //角度標(biāo)識減1
- count=0;
- if(jd==0)
- jd=1; //已經(jīng)是0度，則保持
- while(jan==0);
- }
- }
- }
- void main()
- {
- jd=13;
- count=0;
- Time0_Init();
- while(1)
- {
- keyscan(); //按鍵掃描
- }
- }
|
|
