先发程序:
#include <reg52.h>
//#include <at89x52.h>
//#include <keyscan.h>
extern void scan_full(void);
extern unsigned char key_scan(void);
extern bit key_ok;
unsigned char pwm_set,key_value;
unsigned char count;
sbit PWM=P3^6;
bit up,down,set_flag;
unsigned char code BCD[]={0x3f,0x06,0x5b,0x4f, //此处是将0-F转换成相应的BCD码
0x66,0x6d,0x7d,0x07,
0x7f,0x6f,0x77,0x7c,
0x39,0x5e,0x79,0x71};
void delay1(unsigned char t)
{
while(t--);
}
void pwm(void) interrupt 5//定时器2产生PWM波形
{
TF2=0; //定时器2的溢出标志要软件清除,
//但当RCLK或TCLK为1时由硬件清除
if((count>=pwm_set)&&(count<10))
PWM=1;
else PWM=0;
count++;
if(count==10)
count=0x00;
}
void key_pwm(unsigned char x)//把键值转化为PWM设置值
{
switch(x) //把矩阵键盘转化为独立键盘
{
case 1:up=1;break;
case 2:down=1;break;
case 3:set_flag=!set_flag;break;
default:break;
}
if(up&&set_flag) //设置PWM参数:pwm_set
{
pwm_set++;
up=0;
if(pwm_set>=10)
pwm_set=0x00;
}
if(down&&set_flag)
{
pwm_set--;
down=0;
if(pwm_set==0xff)
pwm_set=9;
}
if(!set_flag)
{
up=0;
down=0;
}
}
void main(void)
{
TH2=0xb1; //定时20MS
TL2=0xe0;
RCAP2H=0xb1;//定时器2溢出时会把这个单元的内容送到TH2和TL2中
RCAP2L=0xe0;
EA=1;
ET2=1;
TR2=1;
while(1)
{
scan_full(); //看是否有键按下
if(key_ok) //有键按下,则判断到底是哪个键按下
{
key_value=key_scan();//键值送key_value暂存
P0=~BCD[key_value]; /*此三句是将键值显示出来*/
P2=0xfe; /** */
delay1(200); /*************************/
key_pwm(key_value); //调用键值转PWM设置参数函数
key_value=0x00; //清除键值,以免一次按下,多次响应
}
P0=~BCD[pwm_set]; /***此三句是将pwm_set值显示出来*/
P2=0xfd; /******* */
delay1(200); /****************************/
}
}
电路图和仿真文件下载:
PWM调温.rar
(48.18 KB, 下载次数: 418)
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