//boolean S == Scale. True == Farenheit; False == Celcius
float DHT_ReadTemperature()
{
bool S = false;
float f;
if (DHT_read()) {
switch (_type) {
case DHT11:
f = data[2];
if (S)
f = DHT_ConvertCtoF(f);
return f;
case DHT22:
case DHT21:
f = data[2] & 0x7F;
f *= 256;
f += data[3];
f /= 10;
if (data[2] & 0x80)
f *= -1;
if (S)
f = DHT_ConvertCtoF(f);
return f;
}
}
return NAN;
}
// return values:
// DHTLIB_OK
// DHTLIB_ERROR_CHECKSUM
// DHTLIB_ERROR_TIMEOUT
int DHT_Read22(dht_t *self)
{
// READ VALUES
int rv = DHT_read(self);
if (rv != DHTLIB_OK)
{
self->humidity = DHTLIB_INVALID_VALUE; // invalid value, or is NaN prefered?
self->temperature = DHTLIB_INVALID_VALUE; // invalid value
return rv;
}
// CONVERT AND STORE
self->humidity = WORD(self->_bits[0], self->_bits[1]) * 0.1;
if (self->_bits[2] & 0x80) // negative temperature
{
self->temperature = WORD(self->_bits[2]&0x7F, self->_bits[3]) * 0.1;
self->temperature *= -1.0;
}
else
{
self->temperature = WORD(self->_bits[2], self->_bits[3]) * 0.1;
}
// TEST CHECKSUM
uint8_t sum = self->_bits[0] + self->_bits[1] + self->_bits[2] + self->_bits[3];
if (self->_bits[4] != sum) return DHTLIB_ERROR_CHECKSUM;
return DHTLIB_OK;
}
float DHT_ReadHumidity(void)
{
float f;
if (DHT_read()) {
switch (_type) {
case DHT11:
f = data[0];
return f;
case DHT22:
case DHT21:
f = data[0];
f *= 256;
f += data[1];
f /= 10;
return f;
}
}
return NAN;
}
// return values:
// DHTLIB_OK
// DHTLIB_ERROR_CHECKSUM
// DHTLIB_ERROR_TIMEOUT
int DHT_Read11(dht_t *self)
{
// READ VALUES
int rv = DHT_read(self);
if (rv != DHTLIB_OK)
{
self->humidity = DHTLIB_INVALID_VALUE; // or is NaN prefered?
self->temperature = DHTLIB_INVALID_VALUE;
return rv;
}
// CONVERT AND STORE
self->humidity = self->_bits[0]; // bit[1] == 0;
self->temperature = self->_bits[2]; // bits[3] == 0;
// TEST CHECKSUM
uint8_t sum = self->_bits[0] + self->_bits[2]; // bits[1] && bits[3] both 0
if (self->_bits[4] != sum) return DHTLIB_ERROR_CHECKSUM;
return DHTLIB_OK;
}
