Can you use data field as basic metrics?

ddje 2 days ago

Hi everyone,

This is my first project here so it may be a dumb question.

I'm working on an phone app + garmin data field to get my ebike info into Garmin.

So far so good, I've manage to get all my metrics Cadence, Power, Motor Power, Battery and Assist Level into a CIQ field and saved in the fit file with fit contributor.

They are correctly logged when use the Datafield trouh Connect IQ.

I'm now wondering if they would be a way for one of those to be recognize "as if it was a sensor". For exemple with a power meter, garmin would calculate Normalize, average etc, thew would also be synced to third party (Strava etc...). Would it be possible for my Datafield power to be treated as such?

flocsy🤠 2 days ago

if your e-bike broadcasts power meter data as such (ANT+ or Bluetooth), then pair it as such to the garmin device.

ddje 1 day ago in reply to flocsy🤠

It doesn't. I decrypted the value trough the Bluetooth signal it sends to its own app. It is not an official CPS or CPC.

flowstate 1 day ago

You can get some 3rd party sites (like Strava) to recognize a developer FIT field recorded by your CIQ data field *in place* of certain native fields (like power), but you will never get Garmin Connect to use such a developer FIT field as if it was native.

Use the :nativeNum option of createField() with the integer value corresponding to the native field you want to "replace". You can look up native field numbers in the FIT profile: profile.xlsx in the Garmin FIT SDK (https://developer.garmin.com/fit/download/)

e.g. to find (instant) power:

- look in the Messages tab

- look for Activity File Messages > Message Name = record

- power is field number 7, and it's a uint16

As mentioned, Garmin Connect completely ignores nativeNum fields (and so does the watch), in the sense that they won't treat such data as if it was native. Your data will still be displayed in Connect, but it won't be treated any differently than any other 3rd-party data.

This technique does work with some 3rd party sites (like Strava) and power, since it's the only way Stryd can record running power in such a way that any site other than Stryd can use it. At least I'm sure it works with power for running activities. Not sure if it works with power for cycling activities.