为什么我用的基于430的DHT11温湿传感器每次测得温度都是2倍

只看该作者 · 2015-6-7 16:07

哪个大神带我看一下
#include <msp430x14x.h>
#define uchar unsigned char
#define uint  unsigned int
#define LCD_RS_EN P3OUT |= BIT0       //寄存器选择输入
#define LCD_RS_CLR  P3OUT &= ~BIT0
#define LCD_RW_EN P3OUT |= BIT1       //液晶读/写控制
#define LCD_RW_CLR  P3OUT &= ~BIT1
#define LCD_EN_EN P3OUT |= BIT2       //液晶使能控制
#define LCD_EN_CLR  P3OUT &= ~BIT2
#define LCD_PSB_EN  P6OUT |= BIT2       //串/并方式控制
#define LCD_PSB_CLR P6OUT &= ~BIT2
//#define LCD
#define HIGH P2OUT|=BIT1;
#define LOW P2OUT&=~BIT1;
char temph,templ,humdh,humdl,check,cal;
uchar address=0;
uchar string[]={"温湿测试系统"};
uchar str_t[]={"温  度："};
uchar str_r[]={"湿  度："};
uchar str_suit[]={"适宜度："};
uchar str1[]={"适  宜"};
uchar str2[]={"不适宜"};
void delay_1ms(uint z)
{
uint i,j;
for(i=z;i>0;i--)
for(j=80;j>0;j--);
}

void DelayNus(uint n)//延时1US函数
{

TACTL|= TASSEL_2+TACLR+ID_3;//定时器A，时钟为SCLK，8分频；
TACTL |= MC_1;          //增计数到CCR0
TACCR0 = n;
while((TACTL & BIT0)!=0x01);  //等待
TACTL &= ~MC_1;       //停止计数
TACTL &= ~BIT0;       //清除中断标志
}

void write_date(uchar date)//12864 写数据
{
LCD_RS_EN;
LCD_RW_CLR;
P4OUT = date;
delay_1ms(5);
LCD_EN_EN;
delay_1ms(5);
LCD_EN_CLR;
}
void write_cmd(uchar cmd)//12864 写指令

{
LCD_RS_CLR;
LCD_RW_CLR;
P4OUT = cmd;
delay_1ms(5);
LCD_EN_EN;
delay_1ms(5);
LCD_EN_CLR;
}

void init12864()//初始化 12864
{

LCD_PSB_EN;          //bingxing
write_cmd(0x30);       //jiben zhi lin ji
delay_1ms(5);
write_cmd(0x0c);
delay_1ms(5);
write_cmd(0x01);
delay_1ms(10);
}

void port_int()
{
  P4DIR |= 0XFF;
  P3DIR |= 0XFF;
}
void init_clk()
{
int i;
WDTCTL=WDTPW+WDTHOLD;
BCSCTL1&=~XT2OFF;
do
{
   IFG1 &=~OFIFG;
   for(i=0xff;i>0;i--);
}
while(IFG1&OFIFG);
BCSCTL2|= SELM_2+SELS;//SCLK，MCLK都选择为外部时钟

}

void display(uchar pos_x,uchar pos_y,uchar string1[],int str_length)
{
  uchar i;
  if(pos_x==1)
   address=0x80+pos_y;
  else if(pos_x==2)
   address=0x90+pos_y;
  else if(pos_x==3)
   address=0x88+pos_y;
  else
   address=0x98+pos_y;
  write_cmd(0x80);
  write_cmd(address);
  delay_1ms(10);
  for(i=0;i<str_length;i++)
write_date(string1[i]);
}

char receive(void)             //接受函数
{
  char temp,cnt=0;                   //临时变量用于存储接受数据
  while(cnt<8)
  {
   while((P2IN&BIT1)==0);             //等待50us的低电平结束
   DelayNus(35);
   if(P2IN&BIT1)                      //长于30us定义为1
   {
      temp++;
      temp<<=1;
      while(P2IN&BIT1);          //结束高电平，即下一位数据的到来
   }
   else
   {
      temp<<=1;
   }
   if(cnt!=7)
      while(!(P2IN&BIT1));             //最后一次给函数返回留下时间
   cnt++;
  }
  return temp;
}
void work_data(void)//DHT11 的初始化函数
{
  P2DIR |= BIT1; //设置P2.1为输出状态
  HIGH;
  _NOP();_NOP();_NOP();
  LOW;
  DelayNus(18000); //开始信号
  HIGH;
  DelayNus(30);
  P2DIR&=~BIT1; //设置P2.1为输入状态,检测传感器响应
  DelayNus(20);    //20US后  P2IN  是否为低电平，不为低电平说明复位失败，重新开始
  while((P2IN&BIT1)!=0)//如果没有检测到响应信号继续发送开始信号，如果没有检测到以上的复位，则重复执行
  {
   P2DIR |= BIT1; //设置P2.1为输出状态
   HIGH;
   _NOP();_NOP();_NOP();
   LOW;
   DelayNus(18000); //开始信号
   HIGH;
   DelayNus(30);
   P2DIR&=~BIT1; //设置P2.1为输入状态,检测传感器响应
   DelayNus(20);
  }
  while((P2IN&BIT1)==0);//等待拉高，准备输出数据
  while(P2IN&BIT1);  //等待低电平，输出数据
                  //下面开始接受数据
  humdh=receive();
  humdl=receive();
  temph=receive();
  templ=receive();
  check=receive();
  cal=humdh+humdl+temph+templ;

}
void main()
{
char R_shi,R_ge,T_shi,T_ge,T_xs1,T_xs2,R_xs;
init_clk();
port_int();
init12864();
display(1,1,string,12);
display(2,0,str_t,8);
display(3,0,str_r,8);
display(4,0,str_suit,8);
delay_1ms(2000);       //越过传感器不稳定状态
while(1)
{
   work_data();
   if(check==cal)
   {
      R_shi = 0x30+humdh / 10;
      R_ge = 0x30+humdh % 10;
      R_xs = 0x30+humdl /10;
      T_shi = 0x30+temph / 10;
      T_ge = 0x30+temph % 10;
      T_xs1 = 0x30+templ/10;
      T_xs2 = 0x30+templ%10;
      write_cmd(0x94);
      write_date(T_shi);
      write_date(T_ge);
      write_date('.');
      write_date(T_xs1);
      write_date(T_xs2);
      write_date(' ');
      write_date(str_t[4]);
      write_date(str_t[5]);
      write_cmd(0x8C);
      write_date(R_shi);
      write_date(R_ge);
      write_date('.');
      write_date(R_xs);
      write_date(' ');
      write_date('%');
      write_date('R');
      write_date('H');
   }
   if(temph>10 && temph<30 && humdh>30 && humdh<60)
      display(4,4,str1,6);
   else
      display(4,4,str2,6);

   delay_1ms(3000);//等待下次采样
}
}