Re: H/W Development question

["Dave McLaughlin" <dave@xxxxxxx>]

Hi Robert,

This is easy with the likes of the PIC or AVR microcontrollers. A
simple
transistor, a couple of resistors and you can detect the state and send
an
RS232 command to the PC. You can could buy an off the shelf module such
as
the Basic Stamp as this would be the quickest way to get it working if
you
don't have any PIC or AVR dev kit. Check out www.milinst.com for the BS2
dev
kit. Might be higher in cost than the likes of the VIOM module from
Phaedrus
(http://www.phaedrusltd.co.uk/system/index.html)
but you will easily find
other interesting projects to put the stamp to good use with. The VIOM
is
also quite large compared to the stamp.

USB is harder but not difficult. Check out the last few issues of Elektor
as
there was an article about using the Cypress USB controller. A mate is
currently trying it out and is most inpressed so far.

Good luck
Dave...


----- Original Message -----
From: "Robert Welsh" <bob-ukha@xxxxxxx>
To: <ukha_d@xxxxxxx>
Sent: Friday, December 06, 2002 9:48 AM
Subject: [ukha_d] H/W Development question


> One for the hardware techies out there...
>
> I discovered last night that my alarm system has a number of
output
> terminals which can be use to drive external devices e.g. ARC or
> diallers.
>
> One of the terminals is a "set" indicator - which is exactly
what I'm
> looking for.
>
> This terminal is 12V normally and drops to 0V on "set"
condition.
> There's also a 13V and a 0V terminal offered on the PCB.
>
> What I'm not sure is how to start designing something simple that
I
> could connect to a serial port to monitor this.
> It seems to me that it's probably the kind of thing that must have
been
> developed 100 times by 100 different people.
>
> Any pointers would be appreciated.
>
> Robert



http://www.automatedhome.co.uk
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