# Create a pocket pedometer just with accelerometer

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1. Dec 15, 2015

### rushi121

Can I create a pocket step counter / pedometer just with accelerometer? If yes, can you explain how can I do that?

The device should detect step irrespective of direction of device.

2. Dec 15, 2015

### Khashishi

Certainly. The easy part is to get it to detect something. The hard part is calibrating it and adjusting it so it properly registers one step per step.

3. Dec 15, 2015

### rushi121

Will that device give false alarm if it is in the car?

4. Dec 15, 2015

### Khashishi

You would want to program it so that it only counts jounces in a certain range of frequencies corresponding to normal human paces. It wouldn't eliminate false counts but it would cut them down.

5. Dec 15, 2015

### A.T.

Depends on what you do in the car.

6. Dec 15, 2015

### Staff: Mentor

I would think all electronic pedometers work this way already.

7. Dec 16, 2015

### meBigGuy

The algorithms to extract footsteps from accelerometers is a high art. Everyone who builds such a product has their own secret sauce for the filters, correlations, etc. There are open source examples for android.
https://www.openhub.net/p/pedometer for example.

Lots of helpful information if you search for "open source pedometer" or "pedometer algorithms"

What about "that's the way everybody does it" and "the hard part is calibrating it" are considered as useful answers?

8. Dec 16, 2015

### Staff: Mentor

You're saying "everybody does it that way" isn't a useful answer? The OP asked if it can be done that way, so saying "everybody does it that way" is a resounding "yes". It's a clear answer to exactly the question asked.

9. Dec 16, 2015

### Staff: Mentor

You can buy pedometers with LCD displays and battery included on alibaba.com for $0.275 each. The cheapest accelerometer chip I can find costs$0.81. That suggests that there must be a much simpler, less expensive, eclectronic way to do it.

10. Dec 16, 2015

### davenn

my wife has owned a number of pedometers (5 - 6) and having looked inside them when doing battery changes
NONE of them use accelerometers
ALL of them used a sprung pendulum arrangement to generate pulses either by a magnet on the pendulum and a hall sensor or a physical switch
being activated as the pendulum bounced up and down

Dave

11. Dec 17, 2015

### Staff: Mentor

My mistake - I would have expected that's obsolete technology that had gone away. So I guess they are still around, though reviewers seem to be steering people away from them:
https://www.walkingwithattitude.com...eter-vs-accelerometer-pedometer-piezoelectric

A lot of people are using mobile phones as pedometers; those as well as fitbit type fitness bands use accelerometers.

12. Dec 17, 2015

### davenn

no mistake made ..... just an observation on my part :)
it would still be the simplest way to DIY build one

yup indeed

13. Dec 17, 2015