It loos like DHT11 only gives rounded values for temperature like 17.0*C.
Is it just how sensor works?
What is the better sensor that can give better precision for temperature and also measures humidity?
I'm fairly certain the rounding is done by the print() member function of the Serial class. The temperature has many places beyond the decimal - you just never see them unless you do "Serial.println(value, precision);"
According to the DHT11 data sheet, the sensor reports the temperature as an 8 bit integer, with resolution 1 degree C and accuracy +/- 2 degrees C, over the range 0 to 50 C.
Use a DS18B20 to measure the temperature.
It is indeed sensor's limitation
Serial.println(temperature, 4);
Just printed 19.0000
Can we conclude that you agree with the information provided in the DHT11 data sheet, summarized in reply #2?
afedorov:
What is the better sensor that can give better precision for temperature and also measures humidity?
The DS18B20 is an obvious choice for temperature and, if you are prepared to go for that, adding two more for the humidity, using wet and dry bulbs, makes some sense. This presupposes you are serious about this, and are prepared to maintain the wet bulb wick.