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sparkfun / SparkFun_SCD4x_Arduino_Library

An Arduino library for the Sensirion SCD4x (SCD40 and SCD41) family of CO2 sensors
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SCD41 sensor returns temperature, humidity but shows CO2=0 #2

Closed kapyaar closed 2 years ago

kapyaar commented 2 years ago

Hi,

I bought both the sensor module by itself (Digikey# 1649-SCD41-D-R2CT-ND), as well as the dev kit for scd41 (digikey# 1649-SEK-SCD41-SENSOR-ND) from digikey. Running the basicReadings example, All works OK with the dev kit. Sample Serial output shows

CO2(ppm):751.00 Temperature(C):20.5 Humidity(%RH):41.7

but with the sensor module (Digikey# 1649-SCD41-D-R2CT-ND), CO2 reading is coming out as zero.

CO2(ppm):0 Temperature(C):21.1 Humidity(%RH):40.8

I have two different modules, This is happening with both modules. Any Idea why?

kapyaar commented 2 years ago

Turns out the VDDH line needs to be powered. A continuity check was beeping between VDD and VDDH but an ohm test showed 8ohms, so definitely not a short. We ran power to both, and now it is working.

nseidle commented 2 years ago

Thanks for coming back to report the fix!