Linking FIT data with watch generated non - FIT data

Nick 8 months ago

I have a watch app that is generating an array of long strings ( up to 400 characters, and up to 300 times in the array ), that I need to display on a website. The website also recieves the Garmin FIT file, and then needs to associate one with the other.

I want this to be automatic and to survive the user uninstalling and reinstalling the application.

I am already using all the fields in the FIT file to transport session summary data, but starting to think the only way I can possibly associate the two, is to also include a custom FIT field that is the unique_ID from the System, device settings.

That way, when the FIT is sent, I can effectively identify the user, and if the app data is sent seperately, I can also identify the same source to link the two together.

Are there other ways ? or is it possible to simply put the array in the FIT file ( not for display on the Garmin website, but so it is available when pushed to the external website? )

Top Replies

Ultra 8 months ago +1

400 characters is too long to record in a single fit developer field. Can you compress that somehow and is the data tied to timestamps? Feels like question better in Connect IQ as your watch app will be…

All Replies

0 Ultra 8 months ago

400 characters is too long to record in a single fit developer field. Can you compress that somehow and is the data tied to timestamps? Feels like question better in Connect IQ as your watch app will be IQ.

In short needs more detail as you’ve given no clue as to what this data represents and how it might be tied to the data in a fit file.

0 Ben FIT 8 months ago

I assume you will be using a CIQ app or data field on the watch, and that the watch will be recording the Activity file. If so, in your CIQ App you can use FIT Contributions to add data to the Session, Lap, or Record messages. You probably want to add the identifying value that links the two data sets to the Session message. This is the relevant topic in the CIQ docs. The CIQ forum would be a good place to ask questions about this as well.
https://developer.garmin.com/connect-iq/core-topics/activity-recording/

Once the data is in the file, you will need to decode it. This recipe in the FIT SDK cookbook contains information on how to do that.
https://developer.garmin.com/fit/cookbook/developer-data/

0 Nick 8 months ago in reply to Ultra

Thanks ultra, that was my concern ( 400 string long being too much ), and why I considered app sent messages instead. No need for timestamps ( they are encoded in the text anyway ) I have up to 300 of these up to 400 strings.

0 Nick 8 months ago in reply to Ultra

Is there any documentation on the string character limit ( assuming worse case of 4 bytes per character ) I mainly use numbers, wit a few letters ?

0 Ultra 8 months ago in reply to Nick

Limit is 255 bytes for a fit field. Assuming your strings have a limited range of characters you could likely compress it from 400 to 255 to fit. Why 300 occurrences though? Presumably you could just write to fit file activity record when each one is required and then no need to embed timestamp:either.