View Full Version : How to monitor voltage ?

03-03-2005, 11:29 AM
I'm still a novice !!
I would like to know how to monitor voltage such as 1-100 vdc both in terms of hardware and code. Thank you.(I did search the forums first but, couldn't find it)

03-03-2005, 10:23 PM
Do you want know when a certain threshold has been reached?! or do you want to know the actual voltage at any time!?

An A/D converter would be one thing that might work...but you'd have to scale it down. And with 100Vdc I'd look to some isolation (optoisolators)!

You could use either a simple voltage divider for the scaling or an op-amp. This is where the experimenting comes in to it...which might work better.

As far as the code goes....look up some of the Nutz&Voltz articles off the Parallax webpage (downloads section I believe). There is an article in there about someone using a photocell and an LED across a battery terminal to determine the voltage on the battery.

I attached the PDF of the article (I think it's the right one)....
Read thru the "What's A Microcontroller" text too! It's a free download from the parallax site. Good beginner material in there!


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