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Topic: peizo knock Example (Read 2 times) previous topic - next topic

afremont



I also read somewhere that if you increase the size of resister, it will increase sensitivity,  any body know anything about that?


I'm pretty sure that the resistor is there to bleed off any DC that might try to build up between the sensor and the high impedance input pin.  A bigger resistor will still do that function, but lengthen the time constant allowing for higher signal peaks I think.  The extra amplification benefits will probably taper off fast as the value is increased.
Experience, it's what you get when you were expecting something else.

Aarwhy

I thank all who have commented, it all helps me. It helps in joining the Dots
You can probably see by my comments, I am mentally challenged when it comes to Electronics, and forums also for that matter.

I just tried another 1K resistor   and it DID improve the sensitivity.
My objective with my Arduino Knock is to make an peizo digitizing sensor for my DIY cnc  machine. 
I have been experimenting with mechanical digitizing probes, but with the vast amount of make & break contacts,  the points give out at about 30 - 40,000.

So I saw this fellows idea,  but I cant contact him.  I wish I could,  I can probe and  produce Gcode  no problem, we could help each other.
So it's trial and error,  and with the the help from others I hope to finally have some success.
http://www.youtube.com/watch?v=DIiWoGUPP78


JimboZA

#13
Mar 09, 2013, 10:34 am Last Edit: Mar 09, 2013, 11:11 am by JimboZA Reason: 1
I did a bit of experimenting with thresholds and resistances, didn't seem to make any difference and I stopped when my eyes glazed over.

Maybe my piezo is indeed configured to buzz only, not sense.

Oh, and on the subject of buzzing, here's a big BZZZZZZZZZZZZZZZZZZZZZZZZZZTTTTTTTT to Erdin (representing the Spelling Police) for this unnecessary pedantry:

Quote
Please modify the Subject in your first post. Peizo -> Piezo

Roy from ITCrowd: Have you tried turning it off an on again?
I'm on LinkedIn: http://www.linkedin.com/in/jimbrownza

Erdin

#14
Mar 09, 2013, 11:03 am Last Edit: Mar 09, 2013, 11:05 am by Erdin Reason: 1

BZZZZZZZZZZZZZZZZZZZZZZZZZZTTTTTTTT to Erdin


I was thinking that if someone searches the forum for "piezo", this thread would not be found. But also the text of the posts is searched. So it isn't a problem.

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