Gadgetbridge: Support for fitbit devices

[ghost]

Your issue is:

Dev with some spare time to help with Fitbit integration

Your wearable device is:

Fitbit Charge HR 2

Your android version is:

Samsung A5 (2016) Running Stock 6.0.1

This will be the first OS adventure I will partake in, do you know if you can pair the device to two apps ? Let's see :)

For Ref.

50

• John

[ghost]

from #50
That would be the first steps. What features of the fitbit are you most interested in?

Step Counting and Heart-Rate

My Medical-Aid provider has a scheme where you earn points for rigorous exercise. Would like the app to help me stay in the appropriate heart-rate zone for a particular time-period.

-John

[ghost]

I'll try to build from source later today, and start with the FitbitCoordinator as suggested in #50 .

[ksala]

Hey, that would be great! I used to have a Fitbit Charge HR, but returned it for a refund when I got sick of needing "the cloud" to do anything with it (you even need to be connected to the internet to change your alarms!).

Sadly, it might not be easy. I did a bit of research before giving my Fitbit back, hopefully it might be helpful. Everything is from what I remember, so it might not be correct.

• Connecting to the fitbit itself might be easy enough. There is this project, written in python, which implements the connection and synching protocol: https://bitbucket.org/benallard/galileo
• Once connected, you can easily get access to the "live data". That's your current data, such as your current number of steps and stairs, your hearth rate and so. No historical data tho.
  From some BT dumps, you could see that the fitbit app was just writing a tiny bit of data to the Charge, and then the Charge would start broadcasting this data back every ~5 seconds or so.
• As for historical data, it might be much harder/impossible. From my understanding, this data is encrypted on the Fitbit itself, and then sent to the application as an opaque binary blob. The application then send the blob to the Fitbit's server, which process it and return back the data and their analysis of it.
  There is some analysis about this here: https://github.com/mrquincle/fitbit-fatbat

Hope it helps, and good luck! Fitbit hardware is quite good, I would love to use it with Gadgetbridge.

[ghost]

That's cool info will definitely check it out. For starters I just want to
pair and get live data.

Still need to check out how to interact with the rest of the app for the
gui stuff.

// edited out the github email stuff
.

[cpfeiffer]

Feel free to ask us anything :-)

[dbrgn]

34c3 fitbit talk: https://media.ccc.de/v/34c3-8908-doping_your_fitbit

[GitHorst]

I think this might be the corresponding manuscript (the 2nd author should be the one from the CCC talk):

https://arxiv.org/pdf/1706.09165.pdf

-- looks very relevant, no? ( @cpfeiffer )