Laptop SPST

Oct 24, 2008 14 Replies

What's the easiest, cheapest way to get a SPST switch capability out of a typical laptop computer these days?



I need a control voltage to switch an external relay, and ideally, an input to confirm that the relay did in fact engage.



Is there a USB or even a PCMCIA doo-hickey thing out there that can do this? My control software will probably be in VB, unless there's good reason to use something else.



No idea is too stupid. :) Thanks.


-mpm



USB to serialport converter, use the control signals

-Lasse

Buy a mechanical SPST switch. Use the laptop as a stick to toggle the switch. Stupid, or genius? You decide.

I stand corrected... :)

These will be USB-only laptops (no legacy serial RS232).

By any chance, does your laptop have a serial port or parallel printer interface? You can directly manipulate the control/handshaking bits, so a SPST function, even with feedback, should be almost trivial.

I'm not even going to hazard a guess if USB or PCMCIA are involved. ;-)

Good Luck! Rich

check out:

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Don...

Don McKenzie Site Map: http://www.dontronics.com/sitemap E-Mail Contact Page: http://www.dontronics.com/email http://www.dontronics-shop.com/super4-usb-relay-module.html http://www.wizard-from-oz.com 1000\'s of electronic items

No parallel port either?

Gee, progress happened, huh?

serial port, via USB if necessary, you get 5 inputs and 3 outputs each.

Bye. Jasen

I've got this one. Not exactly cheap at around $100 but you'd have the feedback thing licked and VB should not be an issue either:

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Comes with a complimentary small edition of a factory automation software. Which is really easy to handle. Just if you want to have fancy looking buttons, and this stuff can more or less be mouse-clicked together.

Check whether it has enough oomph to drive you load.

Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.

Do you like the labjack? I was thinking of getting one.

Joe Chisolm Marble Falls, TX

Yes, I absolutely like it. Simple, works, comes with oodles of SW and has a nice support forum. Once at a client I needed more channels so we bought a $5 USB splitter from Walmart and just kept stacking them.

The only thing I don't like is its blood-red color. Oh well.

Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.

Thanks for the info. I'll have to order one. Bang for the buck seems pretty high.

Joe Chisolm Marble Falls, TX

Supposedly people have automated whole garage-sized breweries with those. Can't really go wrong with a LabJack.

If you do automate stuff with it always keep in mind that if the PC hangs so will (usually) the LabJack. So don't ditch any hardware shut-off techniques.

Also, before you sink a lot of time into writing your own code and programs check out the DAQFactory software that comes with it. Not the full version but who knows, it might already do everything you want.

Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.

Joerg,

Is DAQFactory something like... LabView Lite?

I don't know LabView Lite. DAQFActory is not geared towards research lab type jobs, it is all about factory automation. Basically SCADA:

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The nice thing is that their guys participate in a forum on the LabJack site. So when I found what I'd consider a bug someone got right on it. That impresses me a whole lot more than sales guys in dark suits ;-)

Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.

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