RaresPlescan edited this page Nov 7, 2013 · 10 revisions
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SHT11 is a digital temperature sensor SHT11

It has a nice sensitivity and accuracy and for us was the perfect choice because of the price / features ratio.

Ratings :

Supply voltage : 2.4 V to 5.5 V

Temperature : -40 .. +123 C, resolution 0.01 C, accuracy +- 0.4 C

Humidity ( RH ) : 0 .. 100 %, resolution 0.05 %, accuracy +- 4.5 %

Output : digital, proprietary protocol similar to I2C

Producer's page and documentation :

Product page


The C code is taken from this site : and some modifications were made in order to make its output AWK friendly .

Besides the regular commands for reading temperature and relative humidity and a formula for computing analytical dew point, it features an interesting "heating" command aimed to dry the sensor's reading chamber and provide a feedback check for the temperature ( it is not implemented yet in the current version of the C code.

Our modified code is here : SHT11 source code for Daisy Pi

The executable will output in one line the following values:


-relative humidity

-dew point