Looking for a sensor to detect steps

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kk6gm
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Posted by kk6gm: Wed. Apr 20, 2022 - 12:15 AM
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Often, for reasons of weather or otherwise, I will exercise on a step platform.  I count the steps mentally, but I want to wire up an AVR to do it for me so I can just zone out on music or the TV.  So what I'd like to find is some way to detect each time I step on the platform.  I was thinking of some kind of impact sensor, but I'm not wedded to that.  What's important is that it is easy to interface to an AVR, perhaps via comparator or ADC.  Each impact is in the form BUMP-bump (leading foot - trailing foot).  Any ideas?

 

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Learning and Information, General Electronics, Bosch, Mouser
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gchapman
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Posted by gchapman: Wed. Apr 20, 2022 - 12:26 AM
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BMP581 Barometric Pressure Sensor - Bosch | Mouser

[1/3 page]

FITNESS EXAMPLE: STAIR WALKING

... 

 

"Dare to be naïve." - Buckminster Fuller

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valusoft
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Posted by valusoft: Wed. Apr 20, 2022 - 01:21 AM
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Magnet plus reed switch;

led plus opto sensor;

microphone

microswitch

balloon plus pressure sensor

string plus spring switch

cam plus switch

 

Ross McKenzie, Melbourne Australia

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avrcandies
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Posted by avrcandies: Wed. Apr 20, 2022 - 01:27 AM
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piezo impact sensor (you don't have to directly impact it)

https://www.te.com/usa-en/produc...

 

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allano
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Posted by allano: Wed. Apr 20, 2022 - 01:34 AM
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I used a simple 2g, two axis accelerometer from dimensions engineering  https://www.dimensionengineering... as a sensor and attached it to my leg with an elastic strap just below the knee.  My purpose was to record my pace when I ran.

 

I connected the accelerometer with wires to the analog input of a ATtiny84 and sampled the accelerometer's output at a 5Hz rate, recording its values to external flash memory for processing later on a PC.  I suspect you could find positive and negative acceleration peaks in real time and record a step count.

 

I did put a switched capacitor filter with a cut-off at 2.5hz between the accelerometer and tiny84 but found that for walking or running, that filter was not needed.

 

Alan

 

BTW the waveform of vertical acceleration for a walk is not a simple pseudo sine wave but one that has a smaller, local dip caused  by swinging the leg forward during a walk.

 

Also, my old Garmin Vivofit2 is pretty good a recording and displaying steps .

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Bronze Markjs
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Posted by js: Wed. Apr 20, 2022 - 05:14 AM
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Doesn't any old mobile phone have this built in? ...Or are you looking for a vacuum tube version?.....

John Samperi

Ampertronics Pty. Ltd.

https://www.ampertronics.com.au

* Electronic Design * Custom Products * Contract Assembly

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grohote
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Posted by grohote: Wed. Apr 20, 2022 - 05:39 AM
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kk6gm wrote:
BUMP-bump

 

I remember an unorthodox use of Differential Pressure Sensor mpx100a/mpx200a as a low-frequency sound sensor (microphone).

 

Comment: this is an old module, needs compensations (to be precise as meter)... probably cheep today.

 

 

Last Edited: Wed. Apr 20, 2022 - 05:50 AM
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N.Winterbottom
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Posted by N.Winterbottom: Wed. Apr 20, 2022 - 07:23 AM
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kk6gm wrote:
Each impact is in the form BUMP-bump

Each bump, preceded by a creak & crack from the knees.

 

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meslomp
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Posted by meslomp: Wed. Apr 20, 2022 - 10:35 AM
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I think reading out an accelero meter should be not to big a deal. You could also go for Piezo elements, but then have to find a way to attach and make sure they do not blow up the AVR as with real hard impacts they can punsh a high voltage out. Another one I have seen in the past is a simple read contact. when you run or walk the ground impact migcht be enough to just close the switch without a magnet nearby, I have seen a pace counter like that a number of years ago.

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jgmdesign
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Posted by jgmdesign: Wed. Apr 20, 2022 - 11:43 AM
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Strap a FitBit around your ankle and set it to count steps.  Then multiply the number by two when you are done.

 

used ones can be had on eBay very cheaply.

 

Jim

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kk6gm
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Posted by kk6gm: Wed. Apr 20, 2022 - 03:07 PM
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N.Winterbottom wrote:

kk6gm wrote:
Each impact is in the form BUMP-bump

Each bump, preceded by a creak & crack from the knees.

True, a creak sensor would work as well. :)

 

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kk6gm
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Posted by kk6gm: Wed. Apr 20, 2022 - 03:09 PM
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js wrote:

Doesn't any old mobile phone have this built in? ...Or are you looking for a vacuum tube version?.....

Come to think of it, I'm sure I could find a microphonic tube in my stash... :)

 

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DocJC
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Posted by DocJC: Thu. Apr 21, 2022 - 02:17 AM
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Place a MEMS mic on the floor and filter the output signal.

Each footstep landing on the floor will generate a suitable signal for detection.

Benefit is you don't have to wear it.

 

I used an accelerometer to detect motion before.

I will have to look up the model, but it had several G-scale ranges.

In the most sensitive range, it, too, could detect footsteps approaching it.

 

JC

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kk6gm
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Posted by kk6gm: Tue. Apr 26, 2022 - 10:36 PM
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UPDATE: I've tested these switches and I think they're workable, with proper installation and software debouncing.  They're under a dollar each, which is a plus.  They sometimes miss a step, but I think that's mostly a mounting issue.  Besides, if I miss an occasional step, that just means a slightly longer workout, which is not a bad thing.

 

https://www.adafruit.com/product...

 

As to why not get a FitBit or some other wearable device, it's because I want to watch my progress.  Rather than just knowing how many steps I've done at the end of a session, I want to see a running count of the steps.  This is because I switch leading legs after every 50 steps, and I define a workout as X hundred steps.

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barnacle
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Posted by barnacle: Wed. Apr 27, 2022 - 05:17 AM
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Surely you need a Dalek. If universe cannot be conquered, then steps exist...

 

 

Neil

Neil Barnes
www.nailed-barnacle.co.uk

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Posted by Jeckson: Wed. Apr 27, 2022 - 05:40 AM
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valusoft wrote:
Magnet plus reed switch;

 

This is the cheap solution.

www.tokopedia.com/madagang .Buy and Donated cheap electronics and manuscripts.

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tepalia02
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Posted by tepalia02: Wed. Apr 27, 2022 - 12:36 PM
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You can get some idea from this pedometer tutorial. https://circuitdigest.com/microc...

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