Sensirion SHT temp & hum sensor
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I want to use the SHT chip to measure the dewpoint to determine when
to switch between refrigerated and evaporative cooling in my BS2p
based air conditioner controller.
I checked out Tracy's programs for the SHT chip. They will be a great
help expecially when it comes to the heavy math. But the dewpoint
calculation is still in the "stay tuned" category. [noparse]:([/noparse] I'm staying
tuned.
The range for the temperature is 90 to 120 degrees F and the
relative humidity 5 to 20%. The dewpoint formula on the SHT website
seems to be beyond the capability of the stamp. I was considering a
lookup table (4 colums for temp x 4 rows for humidity) which would
require three linear interpolations to get the dewpoint.
Is this a practical way to do this? Any ideas would be appreciated.
> Marylou
to switch between refrigerated and evaporative cooling in my BS2p
based air conditioner controller.
I checked out Tracy's programs for the SHT chip. They will be a great
help expecially when it comes to the heavy math. But the dewpoint
calculation is still in the "stay tuned" category. [noparse]:([/noparse] I'm staying
tuned.
The range for the temperature is 90 to 120 degrees F and the
relative humidity 5 to 20%. The dewpoint formula on the SHT website
seems to be beyond the capability of the stamp. I was considering a
lookup table (4 colums for temp x 4 rows for humidity) which would
require three linear interpolations to get the dewpoint.
Is this a practical way to do this? Any ideas would be appreciated.
> Marylou
Comments
>to switch between refrigerated and evaporative cooling in my BS2p
>based air conditioner controller.
>
>I checked out Tracy's programs for the SHT chip. They will be a great
>help expecially when it comes to the heavy math. But the dewpoint
>calculation is still in the "stay tuned" category. [noparse]:([/noparse] I'm staying
>tuned.
Okay, dewpoint is there now, in the second program listing at:
http://www.emesystems.com/OL2sht1x.htm
Also a demo of Stamp dew point calculation with keyboard entry
(instead of the Sensirion sensor).
http://www.emesystems.com/programs/dewpoint.bsx
>
>The range for the temperature is 90 to 120 degrees F and the
>relative humidity 5 to 20%. The dewpoint formula on the SHT website
>seems to be beyond the capability of the stamp. I was considering a
>lookup table (4 colums for temp x 4 rows for humidity) which would
>require three linear interpolations to get the dewpoint.
>
>Is this a practical way to do this? Any ideas would be appreciated.
>
> > Marylou
is beyond the capability of a stamp.
Marylou
____________________________________________________
> Okay, dewpoint is there now, in the second program listing at:
> http://www.emesystems.com/OL2sht1x.htm
> Also a demo of Stamp dew point calculation with keyboard entry
> (instead of the Sensirion sensor).
> http://www.emesystems.com/programs/dewpoint.bsx