I have a DHT11 temp sensor that I'm using for a project. Currently, using the DHT-sensor-library-master library, I get a precision of 1c. Since My project uses F, I'd like that refined down to 1f.
Is there any way to increase the precision of the readings to about 1 degree F? I'm not worried about accuracy, +/- a few degress is ok for accuracy, but precision needs increased.
The DHT11 is the cheapest of those sensors. It is for fun, but not very serious. I think it outputs the temperature in 0.1 degrees Celsius. Which library do you use ? Can you give a link to the library ?
The DS18B20 is a good temperature sensor. It is 0.5 degrees Celsius accurate, that is about 1 degree Fahrenheit. It can be set to 12-bits, that is 0.0625 degrees Celsius. You can even use 4 of them and calculate the average and (in theory) double the accuracy.
The DHT11 is only good for 1 C resolution.
A better sensor in the same series is the DHT22 which provides 0.1 C resolution.
Is there any way to increase the precision … I’m not worried about accuracy
What’s the point of increasing the precision if the reading’s wrong in the first place. You’re looking for (b) in the diagram attached?
Thanks mauried for correcting. Now I remember how it was. The datasheet tells that it can do for example "15.6" but the decimal after the dot is always zero, and it returns "15.0" or "16.0".
It's for a thermostat. I really don't care that if the actual temperature is 58f, if it's reading 92f, I'm still cold.
I just didn't like the steps for the thermostat, 1.8f steps makes for jumpy relays.
The issue isn't that serious. I'm not going to replace the sensor if I can't change the precision.
Replace it now or regret it later
The DHT22 humidity/temperature sensor is better, but still not very good. For temperatures the DS18B20 is still the cheapest and best solution for this.
I'm still in pre-deployment with my project, so swapping out a sensor is still feasible.
What makes the DS18B20 superior?
If you arnt concerned about the precision of the readings , then just round up or down the values to the nearest
eg if the reading is 51.5F or less, then round down to 51F, if its greater than 51.5F then round up to 52 F.
To get rid of any jumpiness, average a number of readings over time .
This will give the appearance of 1 F resolution , even if its not all that accurate.