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lightsout
02-13-2005, 11:38 AM
I am very much an amature at basic stamps (BS2p24) and struggle to learn it although my basic electronic/electrical are very good.Anyhow I have spent quite some time trying to figure out how (internet)·to get the stamp to read/sense a signal from an inductive proximity (magnetic wirewound) sensor when being used for shaft RPM. it wil be a 2x signal @ 1000-8000·RPM so I figure a sine wave @ 30 to 300 times a second. I only need to sense differences of 200-500 RPM.·DO I use a capaciter and a resistor then use COUNT on the stamp?? I seen to have found mixed info as to weather the stamp has an onboard AD Converter. Would I be much better off going with a hall effect sensor.Also a simple sample program would be nice of you with a debug of RPM's. I hope thats not too many questions ! Thank you.

Jon Williams
02-13-2005, 11:40 AM
If you can clean-up your sine signal (make it square) you'll be able to use COUNT very reliably.

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Jon Williams
Applications Engineer, Parallax
Dallas, TX· USA

steve_b
02-13-2005, 12:33 PM
I don't know if a schotky will switch fast enough for you, but that's an option maybe.
Might have to amplify first before going in to that.

A Hall sensor is prepackaged and ready to go.· No fuss no muss....not sure if you have to amplify their outputs though.

A reflective pad and a phototran/op will make a reflective counter....

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Steve
http://members.rogers.com/steve.brady (http://members.rogers.com/steve.brady)
"Inside each and every one of us is our one, true authentic swing. Something we was born with. Something that's ours and ours alone. Something that can't be learned... something that's got to be remembered."

Paul Baker
02-13-2005, 02:02 PM
A fast analog comparator may also work. An advantage of those over schotky is you can set the switching voltage, there are also methods for adding hysterisis like a schotky has if you so desire (switch high and switch low voltages are different, it can help with noisy signal)