Measuring watch ticks with microphone

Hello,

As an Arduino and watch enthusiast, I'd like to build a watch analyzer by myself, using our favorite boards.

A "watch analyzer" is a device where you place your watch, and it tells you if it is running late or in advance, and by how many seconds per day.

Yesterday I tried using an FC-109 microphone board, which has a MAX9812 chip : it was a real failure, as I don't understand why the measured sound using analogRead() moves that much, and nothing interesting was recorded.

Today I found a KY-037 board that has an analog mode like the FC-109, but also a digital one : above a given threshold, the measured value is high, else it is low.

Using this digital mode, I'd like to trigger an action on each measured tick, but first I have to be sure that the ticks would be recorded. I'd place my watch on a table, glass down, and would place the microphone on the back of the case where the movement is.

That's where I need your advice : would that work ? Do you have any other idea ? Would the KY-037 detect the small ticks if it very close to the case ?

Thank you.

Try it and you know it.

I would expect not, those are typically designed to pick up hand clapping kind of noise levels. You need a pretty sensitive microphone to pick up such light noises.

A contact microphone is what you need, with quite a lot of amplification. An electret is the wrong sort and
has little sensitivity for vibrations in the body.

You might even find a standard flat piezo element does a good job as a contact mic.

wvmarle:
I would expect not, those are typically designed to pick up hand clapping kind of noise levels. You need a pretty sensitive microphone to pick up such light noises.

That's what I thought, yes... :confused:

MarkT:
A contact microphone is what you need, with quite a lot of amplification. An electret is the wrong sort and
has little sensitivity for vibrations in the body.

You might even find a standard flat piezo element does a good job as a contact mic.

I have a flat piezo buzzer like this one.

Would that work or do I need an even flatter one like this one ?

Just the bare piezo element. I said element, not buzzer.

MarkT:
Just the bare piezo element. I said element, not buzzer.

Like this ?

Aren't piezo buzzers capable of being outputs (making a buzzing sound) and inputs (triggering voltage when detecting vibrations) ?

Thank you for your help.

How much is your time worth?

Sparkfun do a neat little “elephant gun” for $11 which may take you closer to what you want in a single giant step forward…

https://learn.sparkfun.com/tutorials/sound-detector-hookup-guide?_ga=2.39883746.1353709168.1512492984-156026858.1474184854

More than you “need”, of course. But “gets you (most of the way) there”, I would guess!

A small box full of cotton wool, in which you can place watch, with microphone of the sensor in direct contact, and close… to isolate watch and sensor… would probably help a lot. Do be careful about heat build up.

No, that's not a contact microphone, it'll not help.

Pinhapple:
Like this ?

Aren't piezo buzzers capable of being outputs (making a buzzing sound) and inputs (triggering voltage when detecting vibrations) ?

Thank you for your help.

Yes. You need a bare element because you need direct contact, not via air.

tkbyd:
How much is your time worth?

Sparkfun do a neat little "elephant gun" for $11 which may take you closer to what you want in a single giant step forward...

Sound Detector Hookup Guide - learn.sparkfun.com

More than you "need", of course. But "gets you (most of the way) there", I would guess!

A small box full of cotton wool, in which you can place watch, with microphone of the sensor in direct contact, and close... to isolate watch and sensor... would probably help a lot. Do be careful about heat build up.

Elephant gun?

That's not a contact microphone.

This is assuming that the Arduino is an accurate time base.

Elektuur magazine (Dutch), now Elektor, published such a watch "time ballance" project in the Jan 1990 issue.
They used a big 1" piezo disk as contact microphone, and a preamp with threshold detector.
Pictures in post#18 of this thread.
Leo..

http://ihc185.infopop.cc/eve/forums/a/tpc/f/1086047761/m/13710508

MarkT:
No, that's not a contact microphone, it'll not help.
Yes. You need a bare element because you need direct contact, not via air.

Ok, I'll get one.
When using it, would I place the element on a table and then the watch above it, or would I place the watch glass down on a table and then press the element on it ?

I assume I'd have issues with the latter solution as my fingers would be pressed against the element.

Wawa:
Elektuur magazine (Dutch), now Elektor, published such a watch "time ballance" project in the Jan 1990 issue.
They used a big 1" piezo disk as contact microphone, and a preamp with threshold detector.
Pictures in post#18 of this thread.
Leo..

Thank you for the link !

MasterT:
Timing machine sounds - Topic

Thank you too for the link !