SHT7X 시리즈는 I2C 통신으로 온/습도를 읽어올 수 있는 센서입니다.

모아콘에는 CSG (세븐세그먼트 모듈)을 위한 I2C포트가 있습니다. 이 포트를 활용해서 SH17XX를 연결해 보았습니다.

다음은 동작 동영상입니다.

다음은 모아콘 소스코드입니다.

소스 다운로드

#include "moacon500.h"
//#include "csg.h"
 
#define __dataPin 83
#define __clockPin 82
#define csg_delay_clock 26
 
#define LSBFIRST  0
#define MSBFIRST  1
                            //adr  command  r/w
#define STATUS_REG_W 0x06   //000   0011    0
#define STATUS_REG_R 0x07   //000   0011    1
#define MEASURE_TEMP 0x03   //000   0001    1
#define MEASURE_HUMI 0x05   //000   0010    1
#define RESET        0x1e   //000   1111    0
 
void __SCK(u8 val){
 portMode(__clockPin,__OUTOD);
 if(val)portHigh(__clockPin);
 else   portLow(__clockPin);
}
 
void __DATA(u8 val){
 portMode(__dataPin,__OUTOD);
 if(val)portHigh(__dataPin); 
 else   portLow(__dataPin);
}
u8 __RDATA(void){
 u8 i;
 portMode(__dataPin,__IN);
   i = portIn(__dataPin);
   return i;
}
 
void _nop_(void){
  asm ("nop");
  //delaymicro(csg_delay_clock);
}
void s_transstart(void)
//----------------------------------------------------------------------------------
// generates a transmission start 
//       _____         ________
// DATA:      |_______|
//           ___     ___
// SCK : ___|   |___|   |______
{  
   __DATA(1); __SCK(0);                   //Initial state
   _nop_();
   __SCK(1);
   _nop_();
   __DATA(0);
   _nop_();
   __SCK(0);  
   _nop_();_nop_();_nop_();
   __SCK(1);
   _nop_();
   __DATA(1);     
   _nop_();
   __SCK(0);     
}
void s_connectionreset(void)
//----------------------------------------------------------------------------------
// communication reset: DATA-line=1 and at least 9 SCK cycles followed by transstart
//       _____________________________________________________         ________
// DATA:                                                      |_______|
//          _    _    _    _    _    _    _    _    _        ___     ___
// SCK : __| |__| |__| |__| |__| |__| |__| |__| |__| |______|   |___|   |______
{  
  unsigned char i; 
  __DATA(1); __SCK(0);                    //Initial state
  for(i=0;i<9;i++)                  //9 SCK cycles
  { __SCK(1);
    __SCK(0);
  }
  s_transstart();                   //transmission start
}
 
void I2C_shiftOut(u8 bitOrder, u8 val)
{
     u8 i;
     for (i = 0; i < 8; i++)  {
           if (bitOrder == LSBFIRST){
                 if(!!(val & (1 << i))){ __DATA(1); _nop_(); }
                 else           { __DATA(0); _nop_(); }
           }
           else{
                 if( !!(val & (1 << (7 - i)))){ __DATA(1)   ;_nop_(); }
                 else              { __DATA(0)   ;_nop_(); }
           }   
           __SCK(1);_nop_();
           _nop_();_nop_();_nop_();
           __SCK(0);
           _nop_();
     }
}
 
u8 I2C_shiftIn(u8 bitOrder) {
 u8 value = 0, i;
 
 for (i = 0; i < 8; ++i) {
   __SCK(1);_nop_();
   if (bitOrder == LSBFIRST) value |= __RDATA() << i;
   else{ value |= __RDATA() << (7 - i);
         __SCK(0);_nop_(); }
  }
 return value;
}
 
//____________________________________________________________________________________
 
void SHT_sendCommand(u8 command)
{
  s_transstart();
  I2C_shiftOut(MSBFIRST, command);
 
  __SCK(1); _nop_();
  if (__RDATA())printf("ACK ERROR 0\r\n");
  __SCK(0);_nop_();
  if (!__RDATA())printf("ACK ERROR 1\r\n");
}
 
void SHT_waitForResult() {
  // wait for the SHTx answer
  int ack; //acknowledgement
  int i;
  //need to wait up to 2 seconds for the value
  for ( i=0; i<1000; ++i){
    delay(2);
    ack = __RDATA();
    if (ack == 0) break;
  }
  if (ack == 1) printf("ACK ERROR 2\r\n");;
}
 
int SHT_getData() {
 
  u8 MSB = I2C_shiftIn(MSBFIRST);
 
  __DATA(1);
  __DATA(0);
  __SCK(1);
  __SCK(0);
 
  u8 LSB  = I2C_shiftIn(MSBFIRST);
  return ((MSB << 8) | LSB); //combine bits
}
 
void SHT_skipCrc() {
  __DATA(1);   
  __SCK(1);
  __SCK(0);
}
 
float getHumidity() {
  //Return  Relative Humidity
  SHT_sendCommand(MEASURE_HUMI);
  SHT_waitForResult();
  int val = SHT_getData();
  SHT_skipCrc();
  return -4.0 + 0.0405 * val + -0.0000028 * val * val;
}
 
float getTemperature() {
  //Return Temperature in Celsius
  SHT_sendCommand(MEASURE_TEMP);
  SHT_waitForResult();
 
  int val = SHT_getData();
  SHT_skipCrc();
  //return (float)val * 0.01 - 40; //convert to celsius
  return (float)val * 0.01 - 40.1; //convert to celsius
}
 
void cmain(void)
{
 clcdI2cInit(0); // 슬레이브 어드레스는 0 으로 합니다.
 clcdPower(1); // clcd 에 전원을 공급합니다.
 delay(100); 
 
 
 while(1){
  s_connectionreset();
  float humidity = getHumidity();
  float temperature = getTemperature();
 
 
  debugLocate(5,5);
  printf("humidity = %f\r\n",humidity );
  debugLocate(5,8);
  printf("temperature = %f\r\n",temperature );
  delay(20);  
 
 
  clcdPrint (0,0, "=MOACON SHT7x TEST="); 
  clcdPrint (2,1, "Temp : %4.2f C",temperature); 
  clcdPrint (2,2, "Humi : %4.2f %""%",humidity); 
  clcdPrint (1,3, "Humi&Temp Sensor"); 
  delay(30);
 }
}

MOACON 어플리케이션 노트