Well I have seen these things that you can get in the states that control 15
devices or something like that, that you can plu things like heaters or tvs
or what ever into, and control them from you PC's Parrallel port...I have
had mixed results with playing with devices I have made that are controlled
via LPT prot in the past, But these wee black boxes from the stats, ONLY run
on 117v ! so thats no good to me...and they are only about $200 US or there
abouts.
I have a book called, Controlling Your World From The PC", and it says there
are savety thinks you can to to protect your PC from being fried...like
using Solid State Relays, as they can deal with Spikes as they are optical
etc.
Jeremy Coulter
Application Developer
Application Development Centre
Compaq Computer New Zealand Ltd.
Phone: 64 3 371 5724 (DD)
Fax: 64 3 371 5744
Cell: 021 2150435
E-mail: [EMAIL PROTECTED]
Private E-Mail: [EMAIL PROTECTED]
-----Original Message-----
From: Alistair George [mailto:[EMAIL PROTECTED]]
Sent: Friday, May 21, 1999 09:46
To: Multiple recipients of list offtopic
Subject: RE: [DUG-OFFTOPIC]: Controlling external devices from PC
Yes. I agree totally with Peter, Jeremy.
Depending on the situation it can be relatively easy to set one of these up.
For instance, in our application (and Paul Lowman's various) we have been
using a micro called and 8051 (variant) with reasonably low-cost compilers
you can program these beasts in C, or if ur a masochist ASM and in this
family you can even reprogram the source code from a PC via the serial port.
That particular variant has a code kernel which lets you do that, in the
event of remote location code alteration.
Depending on what you are doing of course; if expense and time is a problem
you would be hard-pressed to better what Peter is talking about with the
'Stamp'. If you are going to manufacture plenty I would suggest the 8051
route. There is a plethoria of info on the net - I can send you some urls.
To get up and running you would be looking at Programmer cost of about $200,
a good C assembler (Hitech) for about $700. I could sell you one of my
emulators for about $200 (thats a bit you can plug into your PC and debug
trace and operate ports (similar to running Delphi debug, but with hardware
control as well). Cost of the 8051 micros for a 20k is about $18, for 2k is
about $4. With 20k you can do a hellofalotof program.
Cheers,
Al+
> A 'safer' way would be to interface your computer to a microcontroller via
> serial port, and have the microcontroller deal with the switching of high
> current loads. This means if you screw up only the microcontroller gets
> fried, rather than your expensive computer. You can get a neat little
> microcontroller from dick smith for $150.
>
> This approach also gives you the advantage of not having to have your
> computer on all the time. You can program the micro to do quite complex
> programs - and not even need to talk to your computer. The micro I'm
> thinking of is the Basic Stamp 2, which I have been using for
> over a year in
> small robotic projects.
>
> There are much cheaper micro's, but they require expensive
> programmers, and
> are harder to program. The BS2 is hooked directly to your serial
> port, uses
> easy to learn Token Based Basic, and is pretty robust (I havn't
> broken mine
> yet dispite mistreating it quite a bit).
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