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Ask HN: Is there a fitness wristband that is hackable?

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Re: Ask HN: Is there a fitness wristband that is hackable?

#31
post #25
post #19

Earlier quoted context omitted.

I looked at Pebble and I was surprised to see they were out of business.

Which, from your point of view, isn't a bad thing. It's no longer dependant on external servers, yet still enjoys a lot of support, is easy to code for, plus it's superb as smart watches go. Charging 3 times a month rather than every night means you can track your sleep with it effectively as well.

The alta HR I bought this year and use for sleep tracking has 5 days of battery.

Re: Ask HN: Is there a fitness wristband that is hackable?

#32

Anything is hackable.

Was just about to post a very similar comment. If I was OP I'd buy something cheap (so it doesn't matter if I break it while hacking) and pick it apart until I could get the data.

I'm surprised that you're getting downvoted for this sentiment on a forum that is supposedly "Hacker News". Come on people, where's your hacker spirit?

Re: Ask HN: Is there a fitness wristband that is hackable?

#34
post #27

Anything is hackable.

That's true, I hacked the rear view camera of my car to draw guide lines connected to the wheel position using a pi[1], but it took me tons of effort to reverse engineer the wiring system and CANBUS of my car, I learned a lot (CANBUS is a lot of fun:P), but I don't want that level of involvement here. But I'd like something easier to work with, the "data accessible on the filesystem" of the Garmin seems to be the per…

Having worked extensively with CANBUS and other vehicle interfaces, I cannot remember ever using the word "fun" to describe that line of hacking... :)

Re: Ask HN: Is there a fitness wristband that is hackable?

#35
If you have an iPhone, an Apple Watch meets your description perfectly. It has GPS, heart monitor, and pedometer data, and stores it in your local HealthKit database, which you can easily read and write with your own Swift code running on an iPhone. You can also write apps for the watch directly, and there is a non-LTE model.

Re: Ask HN: Is there a fitness wristband that is hackable?

#36
Amazfit Pace [1]

I just bought one for ~£80 from Gearbest and you can pull the GPX routes from it, and also add routes. You can access all of the files, by plugging a USB lead into the charging dock. It then appears as a USB drive that you can copy files to and from. I've designed my own watch face, as it's just XML and image files and taken GPX data. I'm not sure how or if you can get the heartrate or pedometer data but there is a community on XDA [2] around it so they might be able to help.

The thing that I'm most impressed by is the screen. It is a transreflective display which means that it is always on and just uses the latent light for you to be able to see it, much like a black and white LCD. It does have a backlight, but you only need to put this on when it is dark and you actually need to see the display - much like watches used to be.

1. https://us.amazfit.com/shop/pace?variant=25112

2. https://forum.xda-developers.com/smartwatch/amazfit

Re: Ask HN: Is there a fitness wristband that is hackable?

#38
Some people have hacked the fitbit's synching to save to your personal computer instead of to their servers. I haven't done it since I went with the FitBit Ionic, and it auto syncs. I do like how easy it is to make apps for it though.

Edit: Check out Shimmer:

http://www.getshimmer.co/

Apparently syncs with different devices.

Re: Ask HN: Is there a fitness wristband that is hackable?

#39

Amazfit Pace [1] I just bought one for ~£80 from Gearbest and you can pull the GPX routes from it, and also add routes. You can access all of the files, by plugging a USB lead into the charging dock. It then appears as a USB drive that you can copy files to and from. I've designed my own watch face, as it's just XML and image files and taken GPX data. I'm not sure how or if you can get the heartrate or pedometer data…

What sort of in-use battery life do you get on that? If I were to use it for an ultra run next year, would it be able to last 12 to 18 hours with GPS tracking on for most of that time?

I see the "5 day" claim on the site but these tend to be vastly exaggerated (based on absolutely perfect conditions with everything other than just the watch and maybe step counter functions turned off) in my experience.

Re: Ask HN: Is there a fitness wristband that is hackable?

#40
I have a Garmin Forerunner FR220. When plugged into a Windows 7 computer by the USB device, it shows up as a USB Mass Storage Device, initializing a "Garmin FR620 Flash USB Device", and connects as FAT formatted Flash storage.

Seeing 620 does cause me a bit of annoyance, as I know that my 220, which lacks a number of features of the 620, watch is physically identical just with the speed inhibitor turned off [1]. Makes me miss my TI 430 Chronos, but that didn't have GPS. The FR225 is the first version with the optical heart rate monitor, but I believe it and the current FR235 will behave similarly.

All the activity data is stored on the mass storage device in .FIT files. Here's an example file [2] which you can compare to my Strava upload at [3]. Use the tools at [4] to convert and edit it into GPX format, and the schema at [5] to tease out pedometer/heart rate data from this XML text. You'll probably end up using GPSBabel [6] to analyze it.

Garmin is probably the most common activity tracker for actually running, biking and so on. For just sleep tracking and resting heart rate tracking, or daily step counters, Fitbits that lack GPS are much more popular. But they don't allow manual export of data [7]:

> Welcome to the Fitbit Family @JohnDiver! The stored data on your Fitbit Flex can be taken out only via Bluetooth with an internet connection. It can be synchronized with a computer or with a supported mobile device. Your tracker stores at least 7 days of detailed minute-by-minute data. Summary data (calories, distance, and steps) will be stored for 30 days. If you are experiencing syncing issues, please take a look at the basic troubleshooting steps.

> If the above doesn't help you please let us know what type of difficulties are you having to transfer your data to your Dashboard? Looking forward to your new comments!

The new Garmins do have activity tracking features; I'd be interested to see if their data can be accessed as easily as the .FIT activity files.

[1]: https://www.joelonsoftware.com/2004/12/15/camels-and-rubber-...

[2]: https://drive.google.com/file/d/1H6sBu3XaQgUyTyAhO1Oz7jKL0hx...

[3]: https://www.strava.com/activities/1287343609

[4]: https://www.dcrainmaker.com/tools

[5]: https://www8.garmin.com/xmlschemas/TrackPointExtensionv2.xsd

[6]: https://www.gpsbabel.org/

[7]: https://community.fitbit.com/t5/Flex/Retrieve-raw-data-from-...

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