Garmin Watch Serial Number on GC vs FIT file

Has anyone stumbled on an explanation for why the watch's serial number on GC differs so much from what the watch itself sends in the FILE_ID and DEVICE_INFO messages? GC displays my EPIX2's serial number with alphabetics in it, while the FIT file field is defined and sent as UINT32Z. I can't identify any encoding/decoding system to get from the unsigned integer the watch knows itself as to the string displayed on GC. Anyone have any secrets to share? Thanks!

0 BunBun! over 2 years ago

Like FIT to CSV shows?

Then it's deviceId.

It's used, for example, here: connect.garmin.com/modern/device/***ID***

0 7494571 over 2 years ago in reply to BunBun!

We're on the same page of the hymnal.

The SDK defines the first field of the FILE_ID message as "serial number". My watch sends the unsigned integer 3407959653 in those 32 bits.

/modern/device/3407959653 contains:

There almost has to be an algorithm to get from the unsigned integer to the above code.

0 BunBun! over 2 years ago in reply to 7494571

The Connect just reads it, deviceId and serialNumber are separate fields.

It uses: .../device-service/deviceservice/device-info/***ID*** to get serialNumber, it returns JSON with data about a device, you can check on Network in DevTools (F12). Directly the service doesn't reply, you need correct headers.

So probably it's just wrongly described for FIT.

0 7494571 over 2 years ago in reply to BunBun!

Not the answer I hoped for, but appreciated information nonetheless. I was hoping to be able to derive the integer to use in the FIT from the Serial Number displayed on the web page, but that's looking less and less likely to be possible.

0 MostafaMossaad 10 months ago

Hello,
This seems like the right place to ask, but I think my question is the opposite of this. I have the "serial number" from the .FIT file using https://www.fitfileviewer.com/ (It's for an HRM Pro), and I need the Garmin (proper?) serial number.
I tried to use the connect.garmin.com/modern/device/***ID*** but I got an error "Sorry, we're having trouble with this page.". Even though I get the right page if I used the "serial number" for the watch itself. Can anyone help? Thank you.

0 7494571 10 months ago in reply to MostafaMossaad

I wouldn't have guessed peripheral devices like a heart rate strap would be accessible through /modern/device/ID. Its not clear what information would be available for such devices even if there is a secret way to get to the resource. Good luck.