Hi gusp,

I see in your order that you bough to us the following sensors:

https://www.cooking-hacks.com/no2-gas-sensor-5370
https://www.cooking-hacks.com/volatile- ... ensor-5369

They are sensors for Waspmote and we have never tried it with Arduino or Raspberry. All the information available for these sensors is in the product page of each one and in this document for Waspmote:

http://www.libelium.com/downloads/docum ... rd_3.0.pdf

About the MQ-135 and the htu21d, we have never integrated them with Arduino or Raspberry. You need to contact with the manufacturer of the sensor.

Regards

Hi,

the above two Mics-sensors work perfectly also with Arduino, if you do some preparation of the sensors with resistors to get the right voltages.
I miss from your data sheet as well as from the Figaro-data-sheet some information, how the sensors react to different temperatures and humidities.

Regards,
gusp

Hi,

for all that, its a general question related to gas sensors, whether the quotient of resistances

R(temp,hum,conc)/R(temp,hum,conc0)

remains the same, whatever value temp and hum may take (temperature, humidity).
Libelium-staff members you should know this at least for your gas-sensors.

Regards,
gusp

Hi,

the constancy of this expression enters my temperature-humidity-calibration algorithm in two ways:
1) in the line marked // correct for c1==c0
2) During the calculation of the log10(conc)-value
from the linear relationship of
log10(R(temp,hum,conc)/R(temp,hum,conc0)) = log10(R(temp0,hum0,conc)/R(temp0,hum0,conc0)) to log10(conc).

The linear relationship of log10(R(temp0,hum0,conc)/R(temp0,hum0,conc0)) to log10(conc) is given in most sensor data-sheets.

Regards,
gusp

Hi gusp,


Its nice to see that the sensors works correctly in Arduino. About the information in the datasheet we can't do more, the datasheet is developed by the manufacturer of the sensor not by us.

We know that it is not easy to calibrate them, that's why in Waspmote We have got a board with calibrated sensors.

If you need help with our sensors maybe you can see the Waspmote library of our gas sensor board:
http://www.libelium.com/development/plu ... lications/

Regards