Compressed Speed Distance

Question

Can anyone confirm that speed is a 14 bit number when it's compressed with distance ? I have only one FIT file to base this assumption on.

Ben FIT · Answer

"12 +12 bits over three bytes" is correct. With speed having a scale of 100 and distance having a scale of 16. Speed is an instantaneous value, whereas distance should be accumulated. Look at the decode.c example in the C SDK. It shows how to unpack the values.

nwillink · Answer

Thanks very much for the scales. Yes, I gathered distances are accumulated, which cleverly solves the problem of registering infintely long distances using 12 bits.