Re: Moisture sensor

["k2kyhu" <kzkaram@xxxxxxxxxxx>]

Chris,

The analogue input route is easier to implement for the U/S level
sensor than the RS232 route.

As for the Hi-Fi - as far as I can remember the idea was to do this
via Infra-Red and it required a design and hardware update to our
exsiting ITR (IR transceiver) module which would introduce
reprogramable firmware capability. This has infact been done but no
new firmware has yet been written.

As for the moisture sensor - it needs ac excitation to avoid
electrolytic polarisation then some means of measuring the current
flow. AC excitation can in principle be done using 2 digital outputs
with capacitive filtering. The current flow is likely to be small
(though I have no idea what sort of range) so likely need some
amplification and conversion to voltage before being measurable by,
say, a QAI. So a small bit of electronics between the sensor and a
standard module would be required.

Karam

--- In ukha_d@xxxxxxx, Chris Hunter <cjhunter@...> wrote:
>
> Paul -
>
> Interesting !   A while back I did mention it to Karam, even tried
to
> interest him in adapting the RS232 interface to talk with such
things
> (plus my hi-fi), without success ...
>
> Chris
>
>
> On 14 Apr 2007, at 12:25, lexfordparc wrote:
>
> > Chris,
> >
> > Been there, seen it, got it ;o)
> >
> > This is what I am using to monitor the level of my water butt
> > (eventually I plan to automate the filter on the drain pipe to
turn on
> > and off depending on level in the butt). The Sonic sensor ranges
from
> > 6" to 255" inches with a voltage step for each inch. I
feed this
> > into a
> > Idratek QAI (slightly customised by the guys before dispatched to
go
> > from 0 to 3V instead of the normal 0 to 5v) and it can then be
scaled
> > in Cortex.
> >
> > Paul
> >
> >
> >
> >
> >
> >
>