python SDK weight_scale, weight - potential bug

8294519 14 days ago

I wrote an encoder based on the pythonSDK test_encode_activity_recipe.py. It seemed to work well except for the weight key like below:

mesgs.append({
    'mesg_num': Profile['mesg_num']['WEIGHT_SCALE'],
    'timestamp': scale_date,
    'weight': 8400, #decoding issue?
    'muscle_mass': 66.0,
    })Code

The 'weight' is a weight type and supposed to be in kilograms; however, it seems to scale incorrectly (8400 instead of 84.0kg). The other keys that use mass (eg/ muscle_mass) all convert from to kilograms okay when uploading the FIT file to Connect. Perhaps it's a type weight vs type unit16 issue? Thoughts?

Thanks!

PS Hopefully I'm writing this in the correct place, apologies if not.

0 Eli FIT 13 days ago

Hello, this is the correct place to raise this question.

You are right that the issue is due to the weight field in the weight_scale mesg having a type of weight (enum) rather than a uint16. The weight type is a uint16 value under the hood but is interpreted by the Python and JavaScript SDKs as an enum rather than the intended numeric type.

This causes both the encoder and decoder to handle the value without applying or reversing the scale/offset. For example, when encoding a weight with a decimal e.g. 85.56, the encoder will currently truncate the value to 85 rather than apply the scale of 100.

'weight': {
    '0xFFFE': 'calculating',
},

Thanks for bringing this to our attention! We'll work on getting this fixed in both SDKs and address this post when it has been released.