MSP5438驱动温湿度传感器SHT11，debug有数据，而连续运行得不到数据

2万 · 2020-12-3 09:40

430系列5438A驱动温湿度传感器SHT11，单次debug可以测得温度和湿度值，而连续运行得不到结果。求问原因。
以下为部分代码：

void delay_1us(void)
{
  int sec;
  for(sec=0;sec<8;sec++)
  {
_NOP();
  }
}
void Transmit_Start(void)
{
  P9DIR|=0x02;
  SDA_1(); SCL_0();
  delay_1us();
  SCL_1();
  delay_1us();
  SDA_0();
  delay_1us();
  SCL_0();
  delay_1us();
  SCL_1();
  delay_1us();
  SDA_1();
  delay_1us();
  SCL_0();
}
void Connection_Reset(void)
{
  unsigned int i;
  delay_1us();
  SDA_1();
  delay_1us();
  SCL_0();
  delay_1us();
  for(i = 0; i < 9 ; i++)
  {
SCL_1();
delay_1us();
SCL_0();
delay_1us();
}
  Transmit_Start();
}
char Write_Byte (unsigned char value)
{
  unsigned char k,error=0;
  P9DIR|=0X02;P9REN&=0xFD;//1OUT
  delay_1us();
  for(k=0;k<8;k++,value<<=1)
  {
if(value & 0x80)
{
   SDA_1();
}
else
{
   SDA_0();
}
delay_1us();
SCL_1();
delay_1us();
SCL_0();
delay_1us();
  }
  P9DIR&=0XFD;P9REN|=0x02;P9OUT|=0x02;//9.1Input with pullup resistor

  SCL_1();
  delay_1us();
  error =P9IN&0X02;
  SCL_0();
  delay_1us();

  P9DIR|=0x02;
  delay_1us();
  SDA_1();SDA_1();
  return error;
}

char Read_Byte(unsigned char ack)
{
  unsigned char i,val =0x00;
  P9DIR&=0XFD;P9REN|=0x02;P9OUT|=0x02;//9.1输入模式，选择上拉电阻
  for(i=0;i<8;i++)
  {
val<<=1;
SCL_1();
delay_1us();
if(P9IN&0X02) val =(val|0x1);
SCL_1();
delay_1us();
  }
  P9DIR|=0X02;P9REN&=0xFD;//9.1 OUT
  delay_1us();
  if(ack==1)
  {
SDA_0();
  }
  else
  {
SDA_1();
  }
  _NOP();
  SCL_1();
  delay_1us();
  SCL_0();
  delay_1us();
  P9DIR&=0XFD;P9REN|=0x02;P9OUT|=0x02;//9.1输入模式，选择上拉电阻
  delay_1us();
  return val;
}

char Measure_Mode(unsigned char *P_Value,unsigned char *P_Checksum,unsigned char Mode)
{
unsigned char error=0;
unsigned int i,j;
      Transmit_Start();
switch(Mode)
{
case 0: error+= Write_Byte(measure_temp); break;
case 1: error+= Write_Byte(measure_humi); break;
default: break;
}
      for(j=125;j>0;j--)
      {
      for(i=65535;i>0;i--)
      {
if(P9IN&0X02==0) break;
      }
      if(P9IN&0X02==0) break;
      }
if(P9IN&0X02) error+=1;
*P_Value =Read_Byte(ACK);
*(P_Value+1) =Read_Byte(ACK);
*P_Checksum =Read_Byte(noACK);
      P9DIR|=0x02;
return error;
}

void Cal_SHT11(float *P_Temp,float *P_Humi)
{
const float C1 =-2.0468;
const float C2 =+0.0367;
const float C3 =-0.0000015955;
const float T1 =+0.01;
const float T2 =0.00008;
float rh =*P_Humi;
float t =*P_Temp;
float rh_near,rh_true,t_c;
t_c =t*0.01-40.1;
rh_near =C1+C2*rh+C3*rh*rh;
rh_true =(t_c-25)*(T1+T2*rh)+rh_near;
if(rh_true>100) rh_true=100;    //cut if the value is outside of
      if(rh_true<0.1) rh_true=0.1;    //the physical possible range

*P_Temp =t_c;          //返回温度
*P_Humi =rh_true; //返回相对湿度（rh%）
}

void Data_To_String(SHTscatter *Time,float DATA,float DATA1)
{
unsigned int i;char gewei,shiwei;
   i=(int)DATA;
shiwei=i/10;
gewei =i%10;
   Time->DATAstrings1[0] = shiwei + '0';
Time->DATAstrings1[1] = gewei + '0';
i=(int)((DATA-i)*10);
Time->DATAstrings1[2] ='.';
Time->DATAstrings1[3] = i + '0';
Time->DATAstrings1[4] = '\0';

   i=(int)DATA1;
shiwei=i/10;
gewei =i%10;
   Time->DATAstrings2[0] = shiwei + '0';
Time->DATAstrings2[1] = gewei + '0';
i=(int)((DATA1-i)*10);
Time->DATAstrings2[2] ='.';
Time->DATAstrings2[3] = i + '0';
Time->DATAstrings2[4] = '\0';
}

void Show_Tehu(void)
{
SHTscatter S;
SHTValue Temp_Value,Humi_Value;
unsigned char error,checksum;

error =0;
error =Measure_Mode((unsigned char*) &Humi_Value.i,&checksum,1)+error;  //湿度
error =Measure_Mode((unsigned char*) &Temp_Value.i,&checksum,0)+error;  //温度
      if(error!=0)
      {
      Connection_Reset();
      }
      else
      {
      Humi_Value.f =(float)Humi_Value.i;
      Temp_Value.f =(float)Temp_Value.i;
      Cal_SHT11(&Humi_Value.f,&Temp_Value.f);
      Data_To_String(&S,Temp_Value.f,Humi_Value.f);
      PutStringEN24(188,200,S.DATAstrings1); //温度值
      PutStringEN24(140,200,S.DATAstrings2); //相对湿度值(%)
      }
}

MSP5438驱动温湿度传感器SHT11，debug有数据，而连续运行得不到数据

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