求怎么破 DHT11一直显示00的问题

ID:210834 · 发表于 2017-12-20 12:14

pic单片机程序如下
#include"lian_pic.h"
#include"DHT11.h"
#include"DELAY.h"
#include"LCD.h"
#define _XTAL_FREQ 4000000
uchar data_byte;
uchar RH,RL,TH,TL,R,T;
void start(void)
{

      DH_out;
      DH_io=1;
      __delay_us(8);
      DH_io=0;
      __delay_ms(25);//主机拉低总线发送开始信号大于18ms
      DH_io=1;
      __delay_us(8);
      __delay_us(8);//主机发送开始信号结束，延时20-40us等待DHT11响应
      __delay_us(8);
}
unsigned char receive_byte(void)
{
      uchar i,temp;
      DH_in;
      for(i=0;i<8;i++)
      {
            while(!DH_io);
            __delay_us(8);
            __delay_us(8);
            __delay_us(8);
            temp=0;
            if(DH_io==1)
            temp=1;
            while(DH_io);
            data_byte<<=1;
            data_byte|=temp;
      }
      return data_byte;
}

void receive()
{
      uchar T_H,T_L,R_H,R_L,check,num_check,i;
      start();
      DH_in;
      if(!DH_io)
      {
            while(!DH_io);
            while(DH_io);
            R_H=receive_byte();
            R_L=receive_byte();
            T_H=receive_byte();
            T_L=receive_byte();
            check=receive_byte();
            DH_out;
            DH_io=0;
            for(i=0;i<8;i++)
            __delay_us(8);
            DH_io=1;
            num_check=R_H+R_L+T_H+T_L;
            if(num_check==check)
            {
                     RH=R_H;
                     RL=R_L;
                     TH=T_H;
                     TL=T_L;
                     check=num_check;
            }
      }

}
void show_DHT11(void)
{
      write_com(0x80+2);
      write_data(RH/10+0x30);
      write_data(RH%10+0X30);
      write_com(0x80+0x40+2);
      write_data(TH/10+0x30);
      write_data(TH%10+0x30);
}

ID:288213 · 发表于 2019-4-29 10:05

解决了吗你这个

帐号		自动登录	找回密码
密码			立即注册