Speed detector

JTB

I've worked through most of the WAM workbook for beginners.· Using my BS2, I want to build a combination metronome and speed detector to improve my golf swing (it needs a lot of help).· The speed detector part is the most uncertain.· My first approach·is to have the·club interrupt a two beams (Infrared or laser?) about 5 cm.·apart in the impact zone.· Under these conditions with a club head speed of 100 mph (I wish) we are talking about time measurements in the·1 msec. range.· The flickering light beams would trigger·switching transistors on and off to start and stop a timer loop.

An alternative would the equivalent of a radar gun or mabe a sonic range finder that can process signal changes rapidly.··I like the idea of tight laser beams as·opposed to the fan out of IR but I am not sure of·laser interfacing with·my BS2.

Anybody have any ideas?

Julian

steve_b

An accelerometer would be another way to determine speed. You certainly have to work more on the calculations part of it, but it's doable!

Even putting 2 reflective stickers on the bottom of your club (at a measured distance apart), then have a photodiode/detector pointing up at the swing path.
Then you might be able to get away with using the COUNT command.
Not sure if you'd have issues with sunlight false triggering the detector....

You might also look at hall affect sensors....not sure what the magnetics will do with a metal club head, but the same idea as the relfective tape (at measured difference apart).

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Steve
http://ca.geocities.com/steve.brady@rogers.com/index.html
"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."

KenM

One challenge·to the two beam approach is the sensors sensitivity to ambient light, as steve mentioned, but it can be done.

Have a look at:

http://www.parallax.com/sx/contest/contest_door_velocity.asp

And I think steve may actually have intended to use the·suggest the PULSIN·command, opposed to COUNT. Using COUNT with two sensors a known distance apart will yield two, whereas PULSIN will give you the time between tripping the first and second sensor.

$0.02


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トヨタは　すばらし　です！！

Post Edited (KenM) : 5/13/2005 7:24:45 PM GMT

steve_b

Yes...what KenM said!

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Steve
http://ca.geocities.com/steve.brady@rogers.com/index.html
"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."