[Weather] 1-wire humidity sensor for outdoor use?

[Steinar Midtskogen]

[Paul Davis]

> There is a potential alternative in the Humirel HTM1735. It's spec'ed at
> 0-100% RH operating range. And they say "HTM1735 is specified for accurate
> measurements within 10% to 95%" and "Excursion out of this range (<10% or
> >95%) does not affect the reliability of HTM1735 characteristics." That
> sounds like that's about as good as it's going to get.

Would it be possible to run it on parasite power?  The datasheet says
that it needs 5V and 2.8 mA (4 max).

> This is a linear voltage output sensor, like the HIH-3610/HIH4000. I'm sure
> the slope is different, so you'd need to adjust in software.

I think the Honeywell needs temperature correction in software, while
the Humirel doesn't seem to require that, so the software should be
simpler.  And it should work fine in Oww as of today.  Simply say that
it's a barometer with a suitable slope and offset.

-- 
Steinar