Re: Re: Moisture sensor

[Chris Hunter <cjhunter@xxxxxxxxxxxx>]

Karam -

thanks ... as always !

Chris


On 15 Apr 2007, at 00:32, k2kyhu wrote:

> 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
>>>
>>>
>>>
>>>
>>>
>>>
>>
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