search

practicalarduino / SHT1x

Arduino library to support SHT1x-series (SHT10, SHT11, SHT15) temperature / humidity sensors from Sensirion
http://www.practicalarduino.com/
153 stars 118 forks source link

linear humidity coefficients out of date for newer sensors ( after 2008 ? ) #7

Open cenau opened 10 years ago

cenau commented 10 years ago

Sensors after v3 use a new set of more 'optimised' coefficients. The lib only uses the old ones.

New coefficients

C1 = -2.0468;
C2 = 0.0367;
C3 = -0.0000015955;

relevant lines 82 to 84 in SHT1x.cpp

Most recent datasheet http://www.sensirion.com/fileadmin/user_upload/customers/sensirion/Dokumente/Humidity/Sensirion_Humidity_SHT1x_Datasheet_V5.pdf

Older datasheet explaining the change http://courses.cs.tau.ac.il/embedded/docs/TelosB/SHT11.pdf

LittleHelper00 commented 8 years ago

This optimisation of the coefficients instroduced in Dec 2011 is valid for both Sensirion families SHT1x (SHT10, SHT11, SHT15) and SHT7x (SHT71, SHT75). The lib needs updating with the new values.

Thanks Giulio https://twitter.com/giuliotamberi