A Pedometer in the Real World (2015) | Hacker News Reader

A Pedometer in the Real World (2015)

aosabook.org

109 pointstest_user_12312 comments

I've done this back in iPhone 3 era, and even made a few thousand dollars on the App Store when you could still make money there.

You could improve this by adding a state machine to the algorithm. Basically, only count _repeat_ events, not single events. When you start walking, you start "provisionally" recording the peaks, which can be done fairly easily, but unless it's N peaks or more (IIRC 4 was a good number) within a certain period of time, you don't count those events and don't display them. Once you enter the steady state, count all events. This eliminates a lot of the "steps" that would be recorded due to user fumbling with the device, or other singular, non-step events. This, plus some tuning of the LPF yields an excellent pedometer.

I don't know how it is now, but back in the day the phone would turn off the accelerometer if you lock the screen, and there were also no background tasks of any kind, other than those pre-installed by Apple. So I also had a music player in the app, as well as a fake "lock screen" that would leave the program running, but looked like a real lock screen. The battery would be gone in about 3 hours - this was before the advent of "energy efficient" cores. Total hack, but people paid for it and left good reviews.

> when you could still make money there.

What has changed since? Speaking as someone who has never written apps before but have also wanted to in my spare time, what has changed from before?

People don't pay for little utility apps anymore since Apple/someone else will always end up providing a better version for free.

There is still plenty of money to be made in more powerful apps though. I recently spent $15 on Procreate (A drawing app) and it is currently ranked #1 in its category. The other alternative is subscription pricing which is also very popular with apps these days and often bypasses the Apple tax

Lots of competition, and you have to put in a _ton_ of work to get noticed. Most devs lose money on Apple's App Store I'm sure.

In French, we say podomètre so let’s just say I thought a pedometer measured something else than steps.

I once almost told someone I was going to look for pedophile sites when I was trying to find pedometer nerd sites. Fortunately I realized early enough in the sentence that pedophile is not the right word for "lover of pedometers" and avoided an embarrassing situation.

I didn’t know there were pedometer nerd sites! As someone who has worked on a widely used pedometer, I’d love to see what is being discussed.

Can you please share a link?

This was a long time ago, maybe 20 years or so. I don’t remember if I actually found any.

In English, as long as you pedometer instead of pedo-meter you shouldn't have any misunderstandings.

Bears?

Nice! I recently got a M5Stack Stick controller, which comes with an accelerometer, but the demo pedometer implementation is super basic compared to this! [1]

What other interesting applications have you seen for an acelerometer?

1: https://github.com/Moddable-OpenSource/moddable/blob/public/...

interesting work. I don't see the need for detecting the G vector and multiplying acceleration with that vector, you can use the module and you'd probably get a very similar waveform in any case. Modern accelerometers have built-in logic for step counting and sometimes they are surprisingly accurate.

I worked in this space a little, all the algos are open sourced: https://oxford-step-counter.github.io/

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