Sensors, Motors and Stuff

Started by c04203420 October 2, 2005
Im very new to the world of electronics so forgive my apparent lack
of knowledge.

Input Devices
=============

Could someone point me in the right direction for these. Ideally I
want to spend as little as possible whilst still retaining longivity
and stability of components. Not necessarily pin point accuracy.

I would like a hygrometer sensor if possible. Failing that two
seperate sensors for temp/humidity. I've seen a nice digital temp
sensor. Would this make things easier?
Submersible temp sensors. Any ideas?

A sensor to measure light levels. Perhaps lumen count or something a
little more sophisticated.

Would I be better buying analogue or digital fans. Considering my
project will be working with varying fan speeds then would it be
significantly easier to work with the analog type fans that are
available?

PH level sensors. This I know nothing about yet!

Finally but not 'el ultimo' is the question of motors. I plan on
lowering and highering a High Intensity Discharge lamp relative to
the height of my greens. Will one motor be sufficient or would two be
more reliable or just plain overkill. I had an idea of highering the
lamp when plant tips broke an infared sensor for example. That would
be cool.

Thanks in advance.

Marc



>Input Devices
>=============
>
>Could someone point me in the right direction for these. Ideally
I
>want to spend as little as possible whilst still retaining
longivity
>and stability of components. Not necessarily pin point accuracy.
>
>I would like a hygrometer sensor if possible. Failing that two
>seperate sensors for temp/humidity. I've seen a nice digital temp
>sensor. Would this make things easier?
>Submersible temp sensors. Any ideas?
>

If you do not want to spend too much time on interface circuits,
consider using 1-wire sensors from Maxim/Dallas. All you need is a
4k7 resistor!!! There are plenty of code examples for these
devices available on these pages, and on Netmedia pages. They can
also supply a combined humidity/temp sensor (DS1923). Then you
will have a RTC as well!!.

For submersible sensors I attach a DS18B20 to a circular 1-pair
cable and then I put on a double layer of heat shrink tubing (the
type with glue inside). I have had one of these survive in the sea
at 1m depth for almost two years now. Or you could mould it in
some other way that suit your needs.

Good Luck

Tore Fintland