> Hi all,
>=20
> I'm looking for a relatively cheap (~$10 for humidity sensor, ~$5 or less
> for temperature sensor) for my project.
>=20
> Right now, I'm looking at the following:
>=20
> Temperature: DS18B20 (
> http://ca.mouser.com/ProductDetail/Maxim-Integrated-Products/DS18B20+/?qs=
=3DsGAEpi
> MZZMvbyeSUH4qH%2fLbikZ7SIep9 )
>=20
> Humidity: HIH-5031-001 (
> http://ca.mouser.com/ProductDetail/Honeywell-Microswitch/HIH-5031-001/?qs=
=3DsGAEpi
> MZZMseu6oguAZpqee7rmuRi3v3z4pHD5zNNiU%3d )
>=20

What are your requirements for accuracy?

You can make a 1-wire temp/humidity sensor using a DS2438 + the HIH-5031-00=
1.=20
The DS2438 also contains a temperature sensor but it is only accurate to +/=
-2=20
degrees C while the DS18B20 is accurate to +/-0.5 degrees C, if I remember=
=20
correct.

Here is the circuit:=20

<http://www.sensorsmag.com/sensors/humidity-moisture/a-1-wire-humidity-sens=
or-
1080>

Note that the HIH sensors give you relative humidity and not absolute. You =
also=20
need to do some calculations to get from voltage to RH. This is a lot easie=
r=20
using a high level language and floating point.

/Ruben

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D
Ruben J=F6nsson
AB Liros Electronic
Box 9124, 200 39 Malm=F6, Sweden
TEL INT +46 40142078
FAX INT +46 40947388
ruben@pp.sbbs.se
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D

--=20
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