some ideas

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CharlieM
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some ideas

Post by CharlieM » Mon Jul 11, 2011 10:57 pm

Hello All,

Ok I have been doing some thinking on my ignition. What I think will work the best is to use a timer and measure the time the input is low. kinda like dwell. and from there I can work on what delay I need to get the spark curve I need. Does this seem like a accurate way to measure for engine speed?
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Senacharim
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Post by Senacharim » Tue Jul 12, 2011 6:02 pm

Isn't there a built-in location for connecting an RPM sensor?
I'd think that would be an easier way to gauge speed...
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CharlieM
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Post by CharlieM » Tue Jul 12, 2011 9:43 pm

Hi Senacharim,

This is for model airplane use. the only way I know of reading rpm is off the prop hub using a magnet and a hall sensor.
Running version 2.2.1.9
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Senacharim
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Post by Senacharim » Tue Jul 12, 2011 9:47 pm

Oh!

If your hall effect sensor changes state rapidly enough, then it should be fairly straightforward to wire it to one of the interrupt pins on the PIC.

You'll need a clock or some method of guesstimating when 1 second and/or 1 minute have passed...

IMHO that should work fine.
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Senacharim
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Post by Senacharim » Tue Jul 12, 2011 9:50 pm

Sry, should read a little more into your original reply.

I think so long as your sensor isn't too greatly modifying the electrical characteristics of the ignition then your proposed method should also work... of course you'll need to take steps to blunt the amperage of the ignition from ever reaching your PIC.
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CharlieM
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Post by CharlieM » Tue Jul 12, 2011 11:03 pm

Yesa I have the hardware done. I just to code up a pic.
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Post by bitfogav » Sat Jul 16, 2011 6:07 pm

What exactly does the hardware consists of? :roll:

CharlieM
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Post by CharlieM » Sat Jul 16, 2011 6:53 pm

The hardware consists of a pic,some resistors a npn transistor and two caps.
Running version 2.2.1.9
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