//----------------------------------------------------------------------------------
char sht_do_measure(unsigned char Sensor){
//----------------------------------------------------------------------------------
// sample program that shows how to use SHT11 functions
// 1. connection reset
// 2. measure humidity [ticks](12 bit) and temperature [ticks](14 bit)
// 3. calculate humidity [%RH] and temperature [°C]
// 4. calculate dew point [°C]
// 5. print temperature, humidity, dew point
unsigned int humi_val_i;
unsigned int temp_val_i;
Values humi_val;
Values temp_val;
unsigned char error,checksum;
unsigned int i;
float humi_val_f;
float temp_val_f;
error=sht_SetSensor(Sensor);
sht_connectionreset();
SHTdevice_table[CurrentSensorIndex].valid = 0;
error+=sht_measure(HUMI); //measure humidity
humi_val_i = CurrentValue;
error+=sht_measure(TEMP); //measure temperature
temp_val_i = CurrentValue;
if(error!=0) {
sht_connectionreset();
} //in case of an error: connection reset
else
{ humi_val_f = (float)humi_val_i; //converts integer to float
temp_val_f = (float)temp_val_i; //converts integer to float
calc_sth11(&humi_val_f,&temp_val_f);
SHTdevice_table[CurrentSensorIndex].humidity = (unsigned char)humi_val_f;
SHTdevice_table[CurrentSensorIndex].temperature = (int)(temp_val_f*100);
SHTdevice_table[CurrentSensorIndex].valid = 1;
}
return error;
}
//----------------------------------------------------------------------------------
// measure and check crc (with waiting)
//----------------------------------------------------------------------------------
unsigned char sht_measure_check(unsigned int *value, unsigned char mode)
{
unsigned char checksum;
unsigned int val;
unsigned char data[3];
if (sht_measure((unsigned char*)&val,&checksum,mode)!=0) return 1;
switch (mode)
{
case TEMP: data[0]=MEASURE_TEMP; break;
case HUMI: data[0]=MEASURE_HUMI; break;
default: return 1;
}
data[1]=(unsigned int)val>>8;
data[2]=val;
if (checksum!=sht_crc(data,3)) return 1;
*value=val;
return 0;
}
