Ideas on making an acurate pedometer

Projects General Guidance
1

Hi,

I'm living in Iran and here I couldn't find any good pedometers with reasonable prices, so I decided to make my own pedometer using Arduino. Now, the problem is that I couldn't find sample projects online in which their final outcome would be a helpful device. I mean, they are bulky and power-hungry and simply they are not made and designed for actually using them as one uses a commercially manufactured pedometer. I've tried a few apps on my phone and didn't like them, maybe because there aren't good pedometers for my phone (Nokia Lumia 520 - Microsoft Windows Phone).

My goals in this project are to make a wearable small device (not bulky) with a simple design and an acceptable accuracy which would store time and steps log files onboard (or inside a memory card). A small display screen would be great, but power efficiency and battery usage are one of the most important things to consider. I would further process the data and display them into charts and diagrams, just like Fitbit!

I'm an EE freshman so I don't know much about electronics yet. I'd like to hear your ideas and suggestions. Which Arduino board (or other boards) and sensor do you recommend for this project? Are there any better ways than using accelerometers?

I've also thought of a mechanism like an Electric eye, but with a magnet, but I doubt if it would work well.

2

Is it really not possible for you to order items from places like dx.com or aliexpress?

If not, how will you get parts for your project?

3

jremington:
Is it really not possible for you to order items from places like dx.com or aliexpress?

If not, how will you get parts for your project?

I have access to a lot of accelerometer modules and almost every popular DIY electronics parts locally. I don't trust those cheap chineese devices as they are usually very poor in quality and it's not easy to have them shipped overseas to Iran due to many factors.

Decent pedometers are found here in Iran, but they are overpriced and expensive in Iranian currency. For example, Fitbit Zip is not considered 'cheap' anyway here but it has been designed as a cheap and low-end activity tracker for people in the USA, which is actually cheap there although many users have claimed that it's too fragile and it doesn't last too long.

4

A fitbit costs a lot even in the US (I think the Zip is ~$50+tax and for many that is a lot), but pedometers should be dirt cheap, as the technology has been around for probably decades now. In the US I can get a generic pedometer for $5 if I really wanted, they just aren't Bluetooth enabled or linked up with fancy online accounts but they do the exact same thing (count steps). You may call them cheap Chinese junk, but they are essentially the same as a fitbit minus the "smarts", fancy look, and extremely rough calorie estimates (which can be done more accurately with 2 scales).

If I was going to build a pedometer though I probably wouldn't use an arduino as even the smallest with enough pins (Lilypad) would require soldering to additional components and would probably get too big. The best bet would be a custom PCB with everything on one board with all SMD components. However, that'll be more expensive than buying a cheap pedometer, and probably more than a used fitbit. (You didn't define SWaP, so take this as you will)

Also, you haven't defined acceptable accuracy so people may give you advise that isn't beneficial to you. In my mind pedometers are a waste of time and all of them are accurate enough. Off by 10%, who really cares? 10k steps (an arbitrary number that people love) vs 9k steps doesn't make a difference. Step counting is inherently inaccurate anyways because you are essentially trying to equate motion to steps, so people who talk with their hands get way more steps in then those that don't.

5

I have one of the "cheap Chinese pedometers" and it works amazingly well.

Certainly worth the ~$2 I spent.

But, by all means develop your own. Modern accelerometer chips are all pretty similar in their sensitivity and noise figures, so it really doesn't matter which you choose. It will be your algorithm to determine "steps" that matters.

6

why arduino? Use MIT APP 2 download to your laptop/desktop - windows 10 - read instructions - very easy. Installing App Inventor 2 Setup on Windows - it uses accelerometer. APP works fine on phone - fairly accurate. why go for a hardware device when your phone can do the job?

7

nordlead:
A fitbit costs a lot even in the US (I think the Zip is ~$50+tax and for many that is a lot), but pedometers should be dirt cheap, as the technology has been around for probably decades now. In the US I can get a generic pedometer for $5 if I really wanted, they just aren't Bluetooth enabled or linked up with fancy online accounts but they do the exact same thing (count steps). You may call them cheap Chinese junk, but they are essentially the same as a fitbit minus the "smarts", fancy look, and extremely rough calorie estimates (which can be done more accurately with 2 scales).

If I was going to build a pedometer though I probably wouldn't use an arduino as even the smallest with enough pins (Lilypad) would require soldering to additional components and would probably get too big. The best bet would be a custom PCB with everything on one board with all SMD components. However, that'll be more expensive than buying a cheap pedometer, and probably more than a used fitbit. (You didn't define SWaP, so take this as you will)

Also, you haven't defined acceptable accuracy so people may give you advise that isn't beneficial to you. In my mind pedometers are a waste of time and all of them are accurate enough. Off by 10%, who really cares? 10k steps (an arbitrary number that people love) vs 9k steps doesn't make a difference. Step counting is inherently inaccurate anyways because you are essentially trying to equate motion to steps, so people who talk with their hands get way more steps in then those that don't.

I agree. I bought a Rossmax PA-S20, but I'll try making my own pedometer project just for fun and learning later. However, this pedometer that I've just bought is not cheap but I purchased it anyway.

The Arduino Lilypad or custom PCB project that you mentioned also sounds cool. I enjoy making DIY things.

jremington:
I have one of the "cheap Chinese pedometers" and it works amazingly well.

Certainly worth the ~$2 I spent.

But, by all means develop your own. Modern accelerometer chips are all pretty similar in their sensitivity and noise figures, so it really doesn't matter which you choose. It will be your algorithm to determine "steps" that matters.

I didn't mean to offend all Chinese products of course, but believe it or not, I have had lots of bad experience with some of them.
I haven't found those $2 pedometers, but If I could, I would have bought them.

SunilV:
why arduino? Use MIT APP 2 download to your laptop/desktop - windows 10 - read instructions - very easy. Installing App Inventor 2 Setup on Windows - it uses accelerometer. APP works fine on phone - fairly accurate. why go for a hardware device when your phone can do the job?

MIT APP Inventor is great, but my phone's OS is not Android.

8

$2 pedometer

9

jremington:
$2 pedometer

I meant finding them in local shops.