I'm sure this is the solution to implement.
I know almost zero about electronics but am always looking for fun things
to do with 1wire and Raspberry.
Thanks again,
Peter
On Sun, Jul 7, 2013 at 5:34 PM, Jerry Scharf <sch...@lagunawayconsulting.com
> wrote:
> Peter,
>
> KISS says use a multimeter, I started with the 1-wire solution because
> that was the thread. This will work fine but I have to admit the sugar cube
> seems even nicer. Again, measuring with a multimeter is all it takes.
>
> They make wire that is specifically designed to prevent water ingress down
> the length.
>
> jerry
>
>
> On 07/07/2013 01:05 PM, Peter Hollenbeck wrote:
>
> Elegant solution. Would I need a computer? Could I just do it with a
> multimeter? I love my Raspberry Pis but maybe one isn't required in this
> case.
>
> "If I understand the job right, doesn't that mean that you will be doing major
> surgery to dry the compartment and solve the water ingress issues?"
> Absolutely right.
>
> Thank you,
> Peter
>
>
> On Sun, Jul 7, 2013 at 12:18 PM, Jerry Scharf <
> sch...@lagunawayconsulting.com> wrote:
>
>> On 07/06/2013 08:40 AM, Peter Hollenbeck wrote:
>> > I am building a 26 foot wood power boat. The bilge below the cabin and
>> > afterdeck floor is 7 sealed water tight (hopefully) compartments. I
>> > plan no inspection ports but would like a way to detect moisture. If
>> > there were an appropriate sensor I could embed one in each compartment
>> > and occasionally hook up a Raspberry Pi and check for the presence of
>> > water. Cost is a consideration.
>> >
>> > I would appreciate suggestions.
>> > Thanks,
>> > Peter
>> >
>> >
>>
>> Peter,
>>
>> If I understand the job right, doesn't that mean that you will be doing
>> major surgery to dry the compartment and solve the water ingress issues?
>> If so, I think you could just go with a pair of bare copper wires spaced
>> 1/2 inch apart near the back bottom part of the compartment (replacing
>> the wire is the least of your problems if it gets wet.) (Make sure you
>> use separate pieces of tape for the two wires.)
>>
>> You have one wired to ground and the other that is pulled to a fixed
>> voltage with a pair of high resistance resistors (~10^5 range) with one
>> to supply voltage and the one to ground. With no conductance, the wire
>> will stay at the voltage of the resistor voltage divider, with water in
>> the bottom it will drop toward ground. This can be measured with just
>> about any of the voltage sensing 1-wire chips. I would have the
>> resistors and the sense chip attached to the pi and not to the wires. I
>> would just solder the lengths of copper to insulated, waterproof wire
>> and bring them to a small dry box. In the box you would tie all the
>> grounds together and bring the sense wires to test contacts.
>>
>> You take a first reading for each sense line and record the voltage.
>> When you take follow-on readings, you just need to make sure that the
>> bottom of the boat is tilted so that any water sits at the back of each
>> compartment (I think this is usually the case in motor boats.) Then you
>> connect up a lead, give the sense wire a little while to charge up and
>> take the reading. There may be some systemic error do to
>> time/temperature variations in the system and resistors, This can be
>> factored out by taking a reading with no sense wire attached. It's
>> ability to sense moisture is limited, but significant moisture in the
>> wood would change the resistance between the wires at least somewhat.
>>
>> YMMV
>>
>> jerry
>>
>>
>> ------------------------------------------------------------------------------
>> This SF.net email is sponsored by Windows:
>>
>> Build for Windows Store.
>>
>> http://p.sf.net/sfu/windows-dev2dev
>> _______________________________________________
>> Owfs-developers mailing list
>> Owfs-developers@lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/owfs-developers
>>
>
>
>
> ------------------------------------------------------------------------------
> This SF.net email is sponsored by Windows:
>
> Build for Windows Store.
> http://p.sf.net/sfu/windows-dev2dev
>
>
>
> _______________________________________________
> Owfs-developers mailing
> listOwfs-developers@lists.sourceforge.nethttps://lists.sourceforge.net/lists/listinfo/owfs-developers
>
>
>
>
> ------------------------------------------------------------------------------
> This SF.net email is sponsored by Windows:
>
> Build for Windows Store.
>
> http://p.sf.net/sfu/windows-dev2dev
> _______________________________________________
> Owfs-developers mailing list
> Owfs-developers@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/owfs-developers
>
>
------------------------------------------------------------------------------
This SF.net email is sponsored by Windows:
Build for Windows Store.
http://p.sf.net/sfu/windows-dev2dev
_______________________________________________
Owfs-developers mailing list
Owfs-developers@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/owfs-developers
