int
TemperGetOtherStuff(Temper *t, char *buf, int length)
{
TemperSendCommand(t, 10, 11, 12, 13, 0, 0, 2, 0);
TemperSendCommand(t, 0x52, 0, 0, 0, 0, 0, 0, 0);
TemperSendCommand(t, 10, 11, 12, 13, 0, 0, 1, 0);
return TemperGetData(t, buf, length);
}
int
TemperGetTempAndRelHum(Temper *t, double *tempC, double *relhum)
{
char buf[256];
int ret, temperature, rh, i;
double temp_hum;
TemperSendCommand(t, 10, 11, 12, 13, 0, 0, 2, 0);
TemperSendCommand(t, 0x48, 0, 0, 0, 0, 0, 0, 0);
for(i = 0; i < 7; i++) {
TemperSendCommand(t, 0, 0, 0, 0, 0, 0, 0, 0);
}
TemperSendCommand(t, 10, 11, 12, 13, 0, 0, 1, 0);
/* According to Sensirion datasheet for SHT1x the time for
8/12/14 bit measurements is 20/80/320 ms. Trial and error
suggests that sleeping less that 400ms can produce spurious
measurements */
usleep(400000); ret = TemperGetData(t, buf, 256); if(ret < 2)
{ return -1; }
if(t->debug) {
printf("TempAndRelHum (%d bytes):\n", ret);
for(i = 0; i < ret; i++) {
printf(" %02x", buf[i]);
if(i % 16 == 15) {
printf("\n");
}
}
printf("\n");
}
/* Numerical constants below come from the Sensirion SHT1x
datasheet (Table 9 for temperature and Table 6 for humidity */
temperature = (buf[1] & 0xFF) + (buf[0] << 8);
*tempC = -39.7 + .01*temperature;
rh = (buf[3] & 0xFF) + ((buf[2] & 0xFF) << 8);
temp_hum = -2.0468 + 0.0367*rh - 1.5955e-6*rh*rh;
*relhum = (*tempC-25)*(.01 + .00008 * rh) + temp_hum;
return 0;
}
int
TemperGetTemperatureInC(Temper *t, float *tempC)
{
char buf[256];
int ret, temperature, i;
TemperSendCommand(t, 10, 11, 12, 13, 0, 0, 2, 0);
TemperSendCommand(t, 0x54, 0, 0, 0, 0, 0, 0, 0);
for(i = 0; i < 7; i++) {
TemperSendCommand(t, 0, 0, 0, 0, 0, 0, 0, 0);
}
TemperSendCommand(t, 10, 11, 12, 13, 0, 0, 1, 0);
ret = TemperGetData(t, buf, 256);
if(ret < 2) {
return -1;
}
temperature = (buf[1] & 0xFF) + (buf[0] << 8);
temperature += 1152; // calibration value
*tempC = temperature * (125.0 / 32000.0);
return 0;
}
